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1
Sulistiarini, Diah, e Eka Fatmawati Tihurua. "Leaf Anatomy of Three Varians of Arundina graminifolia (D. Don.) Hochr". Jurnal Natur Indonesia 11, n. 2 (20 novembre 2012): 78. http://dx.doi.org/10.31258/jnat.11.2.78-82.
Testo completoAbstract (sommario):
Three variations of Arundina graminifolia flowers have been recognized, (1) group of big flower with reddish violetlip and purplelish white sepals and petals (2) group of small flower with white lip and white sepals and petals (3)similar to second variation but with purple color on the lip apex. In order to clarify the taxonomy status of thosethree variations, a leaf anatomical study had been carried out. Results of this study showed that there were somedifferences among them in trichome shape and number mesophyll layers. Big flower group of Arundina hastrichome club shape and thick mucous in the apex with mesophyll layer 9-11; for small flower group has white lip,trichome club shape, thick mucous and granulate in the apex, but only 2 mesophyl layers; whereas for other smallflower group with purple lip has trichome cup shape and 10-13 layers of mesophyll. Based on the differences inflower size and their color variation, and combined with leaf anatomical study, we suggested the three variationsof A. graminifolia should be in separated groups.
2
Liljebjelke, Karen A., e Vincent R. Franceschi. "Differentiation of Mesophyll and Paraveinal Mesophyll in Soybean Leaf". Botanical Gazette 152, n. 1 (marzo 1991): 34–41. http://dx.doi.org/10.1086/337860.
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3
Lersten, Nels R., e Curt L. Brubaker. "Paraveinal mesophyll, and its relationship to vein endings, in Solidago canadensis (Asteraceae)". Canadian Journal of Botany 67, n. 5 (1 maggio 1989): 1429–33. http://dx.doi.org/10.1139/b89-190.
Testo completoAbstract (sommario):
Paraveinal mesophyll is described from leaves of a common goldenrod species, Solidago canadensis L. (tribe Astereae). This is the first report of paraveinal mesophyll from the Asteraceae. It is a uniseriate middle layer consisting of horizontally lobed cells that form a lacy meshwork between veins. It abuts the tightly cylindrical bundle sheath at the level of the xylem in all vascular bundles. Vein endings, however, differ from other vascular bundles in two ways: sieve tube members may extend to the vein tip, end at an intermediate point, or be absent, and lateral bundle sheath cells distal to the terminal sieve tube member swell greatly or protrude horizontally and interdigitate with adjacent paraveinal mesophyll cells. Cells of both paraveinal mesophyll and bundle sheath have fewer and smaller chloroplasts than other mesophyll cells; the chloroplasts mostly lie adjacent to intercellular spaces. During leaf development, the paraveinal mesophyll layer differentiates before other mesophyll layers. Solidago canadensis paraveinal mesophyll resembles the well-studied paraveinal mesophyll of Glycine max, except for differences in its anatomical relationship to minor veins and vein endings.
4
Kevekordes, K. G., M. E. McCully e M. J. Canny. "The occurrence of an extended bundle sheath system (paraveinal mesophyll) in the legumes". Canadian Journal of Botany 66, n. 1 (1 gennaio 1988): 94–100. http://dx.doi.org/10.1139/b88-014.
Testo completoAbstract (sommario):
The tissue previously described as paraveinal mesophyll in soybean leaves is shown to have the characters of bundle sheath rather than mesophyll cells and is renamed "extended bundle sheath" (EBS) tissue. Its presence was surveyed by leaf clearing in 66 species of legumes of all three subfamilies. A complete extended bundle sheath system similar to that previously described in soybean was identified in 21 of the species. This system is a paradermally oriented tissue, one cell deep, between the spongy and palisade mesophylls, consisting of extended bundle sheath cells, which join each other across the interveinal space either directly or via bridging cells of somewhat similar shape and size. A newly recognized, attenuated extended bundle sheath system, in which bundle sheath cells extend but do not form a continuum except in very narrow interveinal spaces, is described; it was found in 32 species. Extended bundle sheath tissue was absent from 13 of the species. The presence or form of extended bundle sheath tissue does not follow traditional taxonomic divisions. Extended bundle sheath systems were also found in 3 of 5 nonlegume species.
5
Kim, InSun, e David G. Fisher. "Structural aspects of the leaves of seven species of Portulaca growing in Hawaii". Canadian Journal of Botany 68, n. 8 (1 agosto 1990): 1803–11. http://dx.doi.org/10.1139/b90-233.
Testo completoAbstract (sommario):
Seven species of Portulaca growing in Hawaii can be divided into two groups based on the morphology, anatomy, and ultrastructure of their leaves. Portulaca oleracea, P. molokiniensis, P. lutea, forming group A, have spatulate to obovate leaves, paradermal minor veins, and mesophyll cells that completely encircle the minor veins. The chloroplasts in their bundle sheath cells are larger than those in the mesophyll cells and have well-developed grana and reduced peripheral reticulum. Bundle sheath mitochondria are larger and more numerous than those in the mesophyll, and chloroplasts in the mesophyll cells have well-developed grana and peripheral reticulum. Portulaca pilosa, P. villosa, P. sclerocarpa, and P. "ulupalakua," forming group B, have lanceolate to oblong–oblanceolate leaves, peripheral minor veins, and incomplete wreaths of mesophyll cells. The choroplasts in their bundle sheath cells are about the same size as those in the mesophyll and have reduced grana and well-developed peripheral reticulum. The bundle sheath mitochondria are about the same in size and number as those in the mesophyll, and the mesophyll chloroplasts have well-developed grana and reduced peripheral reticulum. Groups A and B may be equivalent, respectively, to types ii and i of R. C. Carolin, S. W. L. Jacobs, and M. Vesk (Aust. J. Bot. 26: 683–698, 1978) and to coronary subtypes B and A of E. V. Voznesenskaya and Y. V. Gamalei (Bot. Zh. Leningrad, 71: 1291–1306, 1986), which constitute groupings of Portulaca species studied by those authors.
6
Pshennikova, L. M. "The implication of leaf anatomical structure for the selective breeding of lilacs". Vavilov Journal of Genetics and Breeding 25, n. 5 (10 settembre 2021): 534–42. http://dx.doi.org/10.18699/vj21.060.
Testo completoAbstract (sommario):
The cultivars of the common lilac (Syringa vulgaris) grown in the south of the Russian Far East are not always winter-hardy and are often damaged by fungal diseases due to a very humid climate. A promising trend in the selective breeding of lilacs in Russia is the creation of new breeding material based on the gene pool of the broadleaf lilac (S. oblata) and its hybrids in order to introduce valuable adaptive traits into cultivars. The present work aimed to identify the traits of leaf anatomy in species and cultivars of Syringa resistant and susceptible to Pseudocercospora lilacis, the causative agent of brown leaf spot disease. The study was carried out on the living collection of the Botanical Garden-Institute, Far Eastern Branch, Russian Academy of Sciences (Vladivostok). The leaf anatomical structure of two Syringa species showing different degrees of resistance to P. lilacis in the monsoon climate of the Far East (resistant S. oblata and weakly resistant S. vulgaris, and also their hybrid cultivars) has been analyzed. The differences between species, subspecies, and cultivars are quantitative: they differ in the number of spongy mesophyll layers, the cell height in the first layer of palisade mesophyll, the cell height in the upper and lower epidermises, and the thickness of both mesophylls. The interspecific hybrids resistant or weakly resistant to P. lilacis (brown leaf spot disease) mainly retain the leaf anatomy structure of the maternal plant. One of the traits determining the resistance of hybrid lilac cultivars is an increased number of spongy mesophyll layers in the leaf blade. The study of leaf anatomy has shown that the four-layered spongy mesophyll leaf parenchyma correlates with the resistance of lilacs from the subsection Euvulgaris to P. lilacis. In S. oblata, this trait is inherited down the maternal line. To establish lilac cultivars resistant to fungal diseases, it is advisable to cross the two species (S. oblata and S. vulgaris) or their cultivars using one of S. oblata subspecies as a maternal plant.
7
Théroux-Rancourt, Guillaume, Adam B. Roddy, J. Mason Earles, Matthew E. Gilbert, Maciej A. Zwieniecki, C. Kevin Boyce, Danny Tholen, Andrew J. McElrone, Kevin A. Simonin e Craig R. Brodersen. "Maximum CO 2 diffusion inside leaves is limited by the scaling of cell size and genome size". Proceedings of the Royal Society B: Biological Sciences 288, n. 1945 (24 febbraio 2021): 20203145. http://dx.doi.org/10.1098/rspb.2020.3145.
Testo completoAbstract (sommario):
Maintaining high rates of photosynthesis in leaves requires efficient movement of CO 2 from the atmosphere to the mesophyll cells inside the leaf where CO 2 is converted into sugar. CO 2 diffusion inside the leaf depends directly on the structure of the mesophyll cells and their surrounding airspace, which have been difficult to characterize because of their inherently three-dimensional organization. Yet faster CO 2 diffusion inside the leaf was probably critical in elevating rates of photosynthesis that occurred among angiosperm lineages. Here we characterize the three-dimensional surface area of the leaf mesophyll across vascular plants. We show that genome size determines the sizes and packing densities of cells in all leaf tissues and that smaller cells enable more mesophyll surface area to be packed into the leaf volume, facilitating higher CO 2 diffusion. Measurements and modelling revealed that the spongy mesophyll layer better facilitates gaseous phase diffusion while the palisade mesophyll layer better facilitates liquid-phase diffusion. Our results demonstrate that genome downsizing among the angiosperms was critical to restructuring the entire pathway of CO 2 diffusion into and through the leaf, maintaining high rates of CO 2 supply to the leaf mesophyll despite declining atmospheric CO 2 levels during the Cretaceous.
8
Gibadulina, I. I., M. V. Larionov e N. N. Maslennikova. "Anatomical and Morphological Features of the Leaves of Tilia Cordata Mill. As an Indicator of the Adaptive Capabilities of the Species to the Conditions of the Urban Environment". IOP Conference Series: Earth and Environmental Science 988, n. 3 (1 febbraio 2022): 032082. http://dx.doi.org/10.1088/1755-1315/988/3/032082.
Testo completoAbstract (sommario):
Abstract Study of the anatomical and morphological features of the photosynthetic apparatus of Tilia cordata Mill. showed that the volume of leaf mesophyll cells in an urbanized environment is higher than in natural plantings. The cells of the palisade mesophyll of the leaf have a greater variability of this indicator during the growing season as compared to the cells of the spongy mesophyll. Positive correlations of the indicator of the volume of cells of the palisade mesophyll with the indicator of the air pollution index, the content of phenol, formaldehyde, benzo(a)pyrene and negative correlations with the content of nitrogen dioxide were noted. The indicator of the volume of cells of the leaf spongy mesophyll positively correlates only with the indicator of the atmospheric pollution index and the content of formaldehyde.
9
Zvereva, G. K. "The structure of the mesophyll and assimilative apparatus of the chloridoid grasses leaves". Проблемы ботаники южной сибири и монголии 19, n. 2 (8 ottobre 2020): 202–6. http://dx.doi.org/10.14258/pbssm.2020103.
Testo completoAbstract (sommario):
The structure of the mesophyll and assimilative apparatus of leaf blades and leaf sheaths was studied atchloridoid grasses Aeluropus intermedius, Cleistogenes squarrosa, Crypsis aculeata and Tripogon chinensis, growing indifferent habitats of Siberia. All plant species are characterized by the manifestation of C4-coronary syndrome. Spatialforms of mesophyll cells radially arranged around Kranz cells and intercostal zone cells were considered. It is shown, thatleaf mesophyll at xerophytes Cleistogenes squarrosa and Tripogon chinensis is composed of cellular cells. At the grasses of saline habitats Aeluropus intermedius and Crypsis aculeata, a simplification of the shape of mesophyll cells is observed, primarily in the intercostal zone and to a greater extent, in leaf sheaths. According to the density of chloroplasts inthe leaf mesophyll, chloridoid С4-grasses approach to mesophytic and xeromesophytic С3-grasses.
10
Fujita, Takashi, Ko Noguchi, Hiroshi Ozaki e Ichiro Terashima. "Confirmation of mesophyll signals controlling stomatal responses by a newly devised transplanting method". Functional Plant Biology 46, n. 5 (2019): 467. http://dx.doi.org/10.1071/fp18250.
Testo completoAbstract (sommario):
There are opposing views on whether the responses of stomata to environmental stimuli are all autonomous reactions of stomatal guard cells or whether mesophyll is involved in these responses. Transplanting isolated epidermis onto mesophyll is a potent methodology for examining the roles of mesophyll-derived signals in stomatal responses. Here we report on development of a new transplanting method. Leaf segments of Commelina communis L. were pretreated in the light or dark at 10, 39 or 70Pa ambient CO2 for 1h. Then the abaxial epidermises were removed and the epidermal strips prepared from the other leaves kept in the dark at 39Pa CO2, were transplanted onto the mesophyll. After illumination of the transplants for 1h at 39Pa CO2, stomatal apertures were measured. We also examined the molecular sizes of the mesophyll signals by inserting the dialysis membrane permeable to molecules smaller than 100–500Da or 500–1000Da between the epidermis and mesophyll. Mesophyll pretreatments in the light at low CO2 partial pressures accelerated stomatal opening in the transplanted epidermal strips, whereas pretreatments at 70Pa CO2 suppressed stomatal opening. Insertion of these dialysis membranes did not suppress stomatal opening significantly at 10Pa CO2 in the light, whereas insertion of the 100–500Da membrane decelerated stomatal closure at high CO2. It is probable that the mesophyll signals inducing stomatal opening at low CO2 in the light would permeate both membranes, and that those inducing stomatal closure at high CO2 would not permeate the 100–500Da membrane. Possible signal compounds are discussed.
11
Johnston, M., CPL Grof e PF Brownell. "Chlorophyll a/b Ratios and Photosystem Activity of Mesophyll and Bundle Sheath Fractions From Sodium-Deficient C4 Plants". Functional Plant Biology 16, n. 6 (1989): 449. http://dx.doi.org/10.1071/pp9890449.
Testo completoAbstract (sommario):
Significantly lower chlorophyll a/b ratios were observed in mesophyll thylakoids extracted from sodium-deficient than normal C4 plants of Amaranthus tricolor, Chloris gayana and Kochia childsii. The chlorophyll a/b ratio of bundle sheath thylakoids was not generally as significantly affected by sodium nutrition as the mesophyll thylakoids. The lower chlorophyll a/b ratio in mesophyll thylakoids of sodium-deficient plants was associated with a lower photosystem II activity. The effect of sodium nutrition on photosystem I activity in the mesophyll thylakoids was dependent upon the species. Although no effect of sodium nutrition on photosystem I was observed in mesophyll thylakoids of K. childsii, photosystem I activity was greater in sodium-deficient than normal plants in A. tricolor. The photosystem II and I activities of the bundle sheath thylakoids were not affected by sodium nutrition in either K. childsii or A. tricolor.
12
Fambrini, M., E. Degl'Innocenti, G. Cionini, C. Pugliesi e L. Guidi. "mesophyll cell defective1, a mutation that disrupts leaf mesophyll differentiation in sunflower". Photosynthetica 48, n. 1 (1 marzo 2010): 135–42. http://dx.doi.org/10.1007/s11099-010-0018-3.
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Hotto, Amber M., Coralie Salesse-Smith, Myat Lin, Florian A. Busch, Isabelle Simpson e David B. Stern. "Rubisco production in maize mesophyll cells through ectopic expression of subunits and chaperones". Journal of Experimental Botany 72, n. 13 (30 aprile 2021): 4930–37. http://dx.doi.org/10.1093/jxb/erab189.
Testo completoAbstract (sommario):
Abstract C4 plants, such as maize, strictly compartmentalize Rubisco to bundle sheath chloroplasts. The molecular basis for the restriction of Rubisco from the more abundant mesophyll chloroplasts is not fully understood. Mesophyll chloroplasts transcribe the Rubisco large subunit gene and, when normally quiescent transcription of the nuclear Rubisco small subunit gene family is overcome by ectopic expression, mesophyll chloroplasts still do not accumulate measurable Rubisco. Here we show that a combination of five ubiquitin promoter-driven nuclear transgenes expressed in maize leads to mesophyll accumulation of assembled Rubisco. These encode the Rubisco large and small subunits, Rubisco assembly factors 1 and 2, and the assembly factor Bundle sheath defective 2. In these plants, Rubisco large subunit accumulates in mesophyll cells, and appears to be assembled into a holoenzyme capable of binding the substrate analog CABP (carboxyarabinitol bisphosphate). Isotope discrimination assays suggest, however, that mesophyll Rubisco is not participating in carbon assimilation in these plants, most probably due to a lack of the substrate ribulose 1,5-bisphosphate and/or Rubisco activase. Overall, this work defines a minimal set of Rubisco assembly factors in planta and may help lead to methods of regulating the C4 pathway.
14
Yudina, P. K., L. A. Ivanov, D. A. Ronzhina e L. A. Ivanova. "Functional differences in leaves and carbon-assimilating tissues between steppe and forest plants in the Altai Mountains". Проблемы ботаники Южной Сибири и Монголии 21, n. 1 (6 giugno 2022): 205–8. http://dx.doi.org/10.14258/pbssm.2022043.
Testo completoAbstract (sommario):
The quantitative traits of the leaf mesophyll were studied for 31 steppe and forest plant species belonging to 21 families in the Altai Mountains at an altitude of 1600-2150 m above sea level. Herbaceous perennials predominated among the studied species. The studied species had an isopalisade, homogeneous and dorsoventral type of leaf meso-phyll structure. Among the species of the forest zone, the dorsoventral type of leaf structure prevailed, in the steppe zone the proportion of species with dorsoventral mesophyll is lower due to the appearance of succulents and species with an isopalisade structure of leaf mesophyll. The species of the forest belt were distinguished low leaf density by larger mesophyll cells and their low number per unit of leaf area compared to steppe plants. As a result the integral leaf mesophyll parameters of the steppe belt species - the number of chloroplasts and the total surface of chloroplasts per unit area of the leaf had higher values compared to the forest belt. It is concluded that the integral parameters of the mesophyll of the leaf strictly correspond to the conditions of species growth.
15
Costigan, Stephen A., Vincent R. Franceschi e Maurice S. B. Ku. "Allantoinase activity and ureide content of mesophyll and paraveinal mesophyll of soybean leaves". Plant Science 50, n. 3 (gennaio 1987): 179–87. http://dx.doi.org/10.1016/0168-9452(87)90072-0.
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Piwonka, Edward J., Jennifer W. MacAdam, Monty S. Kerley e John A. Paterson. "Separation of Mesophyll from Non‐Mesophyll Cell Wall Tissue in Indiangrass Leaf Blades". Agronomy Journal 83, n. 2 (gennaio 1991): 327–30. http://dx.doi.org/10.2134/agronj1991.00021962008300020013x.
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van den Berg, Abby K., Thomas C. Vogelmann e Timothy D. Perkins. "Anthocyanin influence on light absorption within juvenile and senescing sugar maple leaves - do anthocyanins function as photoprotective visible light screens?" Functional Plant Biology 36, n. 9 (2009): 793. http://dx.doi.org/10.1071/fp09030.
Testo completoAbstract (sommario):
Foliar anthocyanins are hypothesised to function as photoprotective visible light screens, preventing over-excitation of the photosynthetic system, and decreasing the likelihood of photo-oxidative stress by absorbing green light and reducing the amount of light available to be absorbed by chloroplasts in deeper tissue layers. Chlorophyll fluorescence imaging was used to test the hypothesis that anthocyanins in the palisade mesophyll of juvenile and senescing sugar maple (Acer saccharum Marsh.) leaves function as visible light screens by assessing their influence on light absorption profiles within leaves. We hypothesised that an effective anthocyanic light screen should reduce light absorption, particularly of green wavelengths, by chloroplasts in the spongy mesophyll. Both anthocyanic juvenile and senescing leaves absorbed greater amounts of green light than corresponding nonanthocyanic leaves. However, profiles of green light absorption by chlorophyll within anthocyanic leaves were not shifted to reflect reduced absorption of green light by spongy mesophyll chloroplasts. Further, the spongy mesophyll of both anthocyanic juvenile and senescing leaves absorbed proportions of green light equal to or greater than the spongy mesophyll of corresponding nonanthocyanic leaves. These results indicate that though they may provide a general source of photoprotection by reducing the total quantity of light available to be absorbed by chlorophyll, the anthocyanins in juvenile and senescing sugar maple leaves do not attenuate light in a manner consistent with that expected for an anthocyanic screen in the palisade mesophyll.
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Mizuki, Inoue, Yoshiharu Sango, Kiyoshi Ishida, Yuko T. Hanba, Masaaki Chiwa, Yoshitoshi Uehara e Atsushi Kume. "Effects of sex and soil water chemistry on leaf morphology and physiology of Myrica gale var. tomentosa". PLOS ONE 17, n. 9 (22 settembre 2022): e0275024. http://dx.doi.org/10.1371/journal.pone.0275024.
Testo completoAbstract (sommario):
Plants respond to environmental stressors, such as an oligotrophic environments, by altering the morphological and physiological functions of their leaves. Sex affects these functions because of the asymmetric cost of reproduction in dioecious plants. We compared the leaf mass per leaf area (LMA), ratio of intercellular air space in leaf mesophyll tissue (mesophyll porosity), palisade thickness, and carbon isotope ratio (δ13C) of leaves of the dioecious shrub Myrica gale based on sex and gradients of soil water chemistry across habitats in the field. The PCA showed that the first three principal components accounted for 84.5% of the variation. PC1 to PC3 were associated with the origin of soil water, nitrogen status of habitats, and sea–salt contributions, respectively. LMA varied from 5.22 to 7.13 μg/cm2, and it was positively related to PC2 and negatively related to PC3, but not to PC1 or sex, suggesting that LMA was low under poor nitrogen conditions and varied with salinity. Mesophyll porosity values were over 50% for all habitats. Mesophyll porosity was positively affected by PC3 and smaller in females than in males. This suggests that M. gale exhibits differences in mesophyll anatomy according to sex. Palisade thickness ranged from 0.466 to 0.559 mm/mm. The leaves of females had thinner palisade layers per mesophyll layer than those of males; however, the habitat did not affect the thickness of the palisade layer per mesophyll layer. The δ13C values of leaves varied from −32.14 to −30.51 ‰. We found that δ13C values were positively related to PC2 but not to PC1, PC3, and sex. Under poor nitrogen conditions, the δ13C of M. gale leaves decreased, suggesting that nutrient deficiency would decrease more under the long-term averaged ratio of photosynthesis than stomatal conductance, leading to low water use efficiency.
19
Thiesen, Leonardo Antonio, Marcos Vinícius Marques Pinheiro, Evandro Holz, Anderson Werner, Elder Eloy, Braulio Otomar Caron e Denise Schmidt. "Phenotypic plasticity of Aloysia citrodora: anatomical changes to water availability and seasons". Comunicata Scientiae 13 (12 giugno 2022): e3590. http://dx.doi.org/10.14295/cs.v13.3590.
Testo completoAbstract (sommario):
The objective was to evaluate the anatomical changes of the leaves of Aloysia citrodora submitted to different water availability during the seasons. The experiment was conducted in a greenhouse, in a randomized block design, bifactorial 4x4, with four seasonal factors (autumn, winter, spring, and summer) and simulations of water availability (25, 50, 75 and 100% of field capacity) with four repetitions. They were evaluated in μm: the thickness of the adaxial and abaxial cuticles, adaxial and abaxial epidermis, palisade and lacunous parenchyma, mesophyll and leaf thickness of the transversal section and the mesophyll and thickness of the main rib and the length and width of the vascular system. In the autumn season, there was a reduction in the width of the vascular system and the thickness of the adaxial cuticle under greater water availability. In winter and under low water availability, there was a reduction in the thickness of the cuticle and adaxial epidermis, lacunous parenchyma, mesophyll and leaf thickness, mesophyll and main rib thickness. In the spring with greater water availability increased in the adaxial and abaxial epidermis, mesophyll and thickness of the main rib, and length of the vascular system; and low water availability provided the greater thickness of the adaxial cuticle, palisade parenchyma, and leaf thickness. In the summer season with the greatest water availability, there was an increase in leaf thickness and adaxial cuticle and a reduction in palisade parenchyma, while low water availability increased the thickness of leaf mesophyll.
20
THOLEN, DANNY, GILBERT ÉTHIER e BERNARD GENTY. "Mesophyll conductance with a twist". Plant, Cell & Environment 37, n. 11 (21 agosto 2014): 2456–58. http://dx.doi.org/10.1111/pce.12401.
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Kakutani, Tadaaki, Shigeo Shibatani e Mitsugi Senda. "Electrorotation of barley mesophyll protoplasts". Bioelectrochemistry and Bioenergetics 31, n. 1 (maggio 1993): 85–97. http://dx.doi.org/10.1016/0302-4598(93)86108-d.
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Cervantes-Martinez, Teresa, Harry T. Horner, Reid G. Palmer, Theodore Hymowitz e A. H. D. Brown. "Calcium oxalate crystal macropatterns in leaves of species from groups Glycine and Shuteria (Glycininae; Phaseoleae; Papilionoideae; Fabaceae)". Canadian Journal of Botany 83, n. 11 (novembre 2005): 1410–21. http://dx.doi.org/10.1139/b05-119.
Testo completoAbstract (sommario):
Calcium oxalate crystal macropatterns in leaves were characterized for 69 species (and two Glycine tomentella cytotypes) from 14 of 16 genera in two legume groups, Glycine and Shuteria, to determine whether they share a common macropattern. A leaf clearing method was used to visualize the crystals. All 69 species (and two Glycine tomentella cytotypes) displayed prismatic crystals associated with leaf veins and vein endings. In contrast, mesophyll crystals occurred in 76.8% of 69 species and two G. tomentella cytotypes, and varied from a few to many. Conversely, only 40.9% of 22 Glycine species (in group Glycine) lacked mesophyll crystals, while 8.7% of 23 species of six genera associated with Glycine (in group Glycine) lacked mesophyll crystals. Thus 24.4% of 45 species of seven combined genera in group Glycine lacked mesophyll crystals. With seven genera in group Shuteria, 20.8% of 24 species lacked mesophyll crystals. The consistently present vein crystals varied in size and shape, so their length–width (Stubby versus Long) crystal ratios were determined for primary, secondary, and tertiary veins, and vein endings. Two trends were evident: Long-crystal ratios increased from primary veins to vein endings in species in both groups, and the perennial and annual Glycine species showed this condition to a greater extent than all the non-Glycine species. In some cases, taxonomically closely associated species were quite similar in their macropattern and presence or absence of mesophyll crystals. These results should be of value to future studies dealing with taxonomy and phylogeny of species in these two leguminous groups.
23
Klauer, Stephen F., Vincent R. Franceschi e Maurice S. B. Ku. "Protein Compositions of Mesophyll and Paraveinal Mesophyll of Soybean Leaves at Various Developmental Stages". Plant Physiology 97, n. 4 (1 dicembre 1991): 1306–16. http://dx.doi.org/10.1104/pp.97.4.1306.
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Romanowska, Elzbieta, e Anna Drozak. "Comparative analysis of biochemical properties of mesophyll and bundle sheath chloroplasts from various subtypes of C4 plants grown at moderate irradiance." Acta Biochimica Polonica 53, n. 4 (14 novembre 2006): 709–19. http://dx.doi.org/10.18388/abp.2006_3298.
Testo completoAbstract (sommario):
The photochemical characteristics of mesophyll and bundle sheath chloroplasts isolated from the leaves of C4 species were investigated in Zea mays (NADP-ME type), Panicum miliaceum (NAD-ME type) and Panicum maximum (PEP-CK type) plants. The aim of this work was to gain information about selected photochemical properties of mesophyll and bundle sheath chloroplasts isolated from C4 plants grown in the same moderate light conditions. Enzymatic as well as mechanical methods were applied for the isolation of bundle sheath chloroplasts. In the case of Z. mays and P. maximum the enzymatic isolation resulted in the loss of some thylakoid polypeptides. It was found that the PSI and PSII activities of mesophyll and bundle sheath chloroplasts of all species studied differed significantly and the differences correlated with the composition of pigment-protein complexes, photophosphorylation efficiency and fluorescence emission characteristic of these chloroplasts. This is the first report showing differences in the photochemical activities between mesophyll chloroplasts of C4 subtypes. Our results also demonstrate that mesophyll and bundle sheath chloroplasts of C4 plants grown in identical light conditions differ significantly with respect to the activity of main thylakoid complexes, suggesting a role of factor(s) other than light in the development of photochemical activity in C4 subtypes.
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Al-Nema, Qutaiba, e Mozahim AL-Mallah. "Electrofusion of mesophyll protoplasts from two varieties of sugar beet, (Beta vulgaris L.)". Journal of Life and Bio Sciences Research 1, n. 1 (23 aprile 2020): 22–25. http://dx.doi.org/10.38094/jlbsr117.
Testo completoAbstract (sommario):
Somatic hybridization between different plants through protoplast fusion represent an efficient experimental approach to produce genetically transformed plant species. Electrofution of mesophyll protoplasts in sugar beet was occurred to overcome the barriers faced breeding program of this economically industrial crop Protoplasts were successfully isolated from leave's mesophyll of two varieties of sugar beet (Beta vulgaris L.). Various enzyme solutions were assessed for the cell wall degrading ability. They express different efficiency in isolation of mesophyll protoplasts of var. Baraka. The protoplasts yield was 18 × 104 cell ml-1 using the mixture consisting of 0.5% Cellulase RS, 1.0% Hemicellulase and 0.1% Pectolyase Y-23 with 13% mannitol. A total of 16 hrs. for cell wall digestion, and protoplast viability approached 93%. Protoplasts were isolated from leaf mesophyll of var. Carola using the same enzymatic mixtures. High protoplasts yield 20 × 104 cell ml-1 was obtained, requiring the same period 16 hrs. to approach viability 96%. The protoplasts were spherical in shape, varied in chloroplast distribution, having size ranged 12 – 52 µm. The present study succeeded in electrofusion between Baraka × Carola mesophyll protoplasts, producing somatic hybrid cells under conditions of 1MHz, 1000 Vcm-1, 2 pulses, 1.5 msec./pulse with fusion percent of 73%.
26
Cao, Jianbo, Chuanliang Chu, Meng Zhang, Limin He, Lihong Qin, Xianghua Li e Meng Yuan. "Different Cell Wall-Degradation Ability Leads to Tissue-Specificity between Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola". Pathogens 9, n. 3 (4 marzo 2020): 187. http://dx.doi.org/10.3390/pathogens9030187.
Testo completoAbstract (sommario):
Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) lead to the devastating rice bacterial diseases and have a very close genetic relationship. There are tissue-specificity differences between Xoo and Xoc, i.e., Xoo only proliferating in xylem vessels and Xoc spreading in intercellular space of mesophyll cell. But there is little known about the determinants of tissue-specificity between Xoo and Xoc. Here we show that Xoc can spread in the intercellular spaces of mesophyll cells to form streak lesions. But Xoo is restricted to growth in the intercellular spaces of mesophyll cells on the inoculation sites. In vivo, Xoc largely breaks the surface and inner structures of cell wall in mesophyll cells in comparison with Xoo. In vitro, Xoc strongly damages the cellulose filter paper in comparison with Xoo. These results suggest that the stronger cell wall-degradation ability of Xoc than that of Xoo may be directly determining the tissue-specificity.
27
McKersie, Bryan D., R. L. Peterson, Stephen R. Bowley e Shankar Das. "Ultrastructural and genetic characterization of a mutant exhibiting starch accumulation and premature leaf senescence in Medicago sativa". Canadian Journal of Botany 70, n. 11 (1 novembre 1992): 2245–53. http://dx.doi.org/10.1139/b92-278.
Testo completoAbstract (sommario):
A mutant was isolated from irradiated seed of alfalfa, Medicago sativa L. cv. Excalibur. The mutant plant, Ex-139, displayed symptoms of premature senescence in the leaf palisade mesophyll. The leaves emerged as a normal phenotype, but light microscopy revealed that they rapidly began to accumulate starch in plastids of some cells in the palisade mesophyll. This accumulation of starch was followed by general cellular autolysis leading to the formation of necrotic regions in the palisade mesophyll. The adjacent epidermal and spongy mesophyll cells were not structurally affected. The mutant otherwise exhibited normal growth and development and was fertile. Inheritance studies indicated that the trait was transmitted to the progeny, preferentially but not exclusively, through the female, which suggests that either there is differential selection among male and female gametes or the trait is controlled by extranuclear DNA. This mutant should be useful in the study of the link between senescence and carbohydrate metabolism and in alfalfa genetics. Key words: starch metabolism, plastid, chloroplast genome, biparental inheritance.
28
Amaliah, Nur Rezqi, Lahming Lahming e Andi Sukainah. "APLIKASI VINEGAR NIRA LONTAR (Borassus flabellifer) UNTUK MENGHAMBAT HISTAMIN PADA IKAN CAKALANG (Katsuwonus pelamis)". Jurnal Pendidikan Teknologi Pertanian 5, n. 1 (10 febbraio 2019): 70. http://dx.doi.org/10.26858/jptp.v5i1.8197.
Testo completoAbstract (sommario):
This study aims to determine the effect of skipjack fish immersion in palm lontar vinegar solution with different storage times at the level of histamine produced. The research design used was Randomized Block Design (RBD). The parameters tested were histamine levels and total mesophyll bacteria. The concentration of vinegar solution at each storage time which had the lowest histamine and the lowest total bacteria was 10% with an average value of 17.34 mg / kg histamine and 4.3 log cfu / ml total bacteria, but a concentration of 6% could inhibit histamine formation. Total mesophyll bacteria were positively correlated with histamine levels in fish, so mesophyll bacteria affected the increase in histamine produced.
29
Ahl, Louise I., Olwen M. Grace, Henriette L. Pedersen, William G. T. Willats, Bodil Jørgensen e Nina Rønsted. "Analyses of Aloe Polysaccharides Using Carbohydrate Microarray Profiling". Journal of AOAC INTERNATIONAL 101, n. 6 (1 novembre 2018): 1720–28. http://dx.doi.org/10.5740/jaoacint.18-0120.
Testo completoAbstract (sommario):
Abstract Background: As the popularity of Aloe vera extracts continues to rise, a desire to fully understand the individual polymer components of the leaf mesophyll, their relation to one another, and the effects they have on the human body are increasing. Polysaccharides present in the leaf mesophyll have been identified as the components responsible for the biological activities of A. vera, and they have been widely studied in the past decades. However, the commonly used methods do not provide the desired platform to conduct large comparative studies of polysaccharide compositions, as most of them require a complete or near-complete fractionation of the polymers. Objective: The objective for this study was to assess whether carbohydrate microarrays could be used for the high-throughput analysis of cell wall polysaccharides in aloe leaf mesophyll. Methods: The method we chose is known as comprehensive microarray polymer profiling (CoMPP) and combines the high-throughput capacity of microarray technology with the specificity of molecular probes. Results: Preliminary findings showed that CoMPP can successfully be used for high-throughput screening of aloe leaf mesophyll tissue. Seventeen species of Aloe and closely related genera were analyzed, and a clear difference in the polysaccharide compositions of the mesophyll tissues was seen. Conclusions: These preliminary data suggest that the polysaccharides vary between species and that true species of Aloe may differ from segregate genera.
30
Oja, VM, BH Rasulov e AH Laisk. "An Analysis of the Temperature Dependence of Photosynthesis Considering the Kinetics of RuP2 Carboxylase and the Pool of RuP2 in Intact Leaves". Functional Plant Biology 15, n. 6 (1988): 737. http://dx.doi.org/10.1071/pp9880737.
Testo completoAbstract (sommario):
Sunflower and cotton plants were grown in growth boxes at 460 �mol m-2 s-1. The mesophyll conductance in N2, the assimilatory charge (post-illumination CO2 uptake) and the CO2 capacity (the solubility of CO2 + HCO3- + CO32-) were measured at different temperatures. The mesophyll conductance had its maximum at 29-30°C in sunflower leaves and rapidly declined at higher and lower temperatures. In cotton, the maximum occurred at a somewhat higher temperature. The assimilatory charge changed in parallel with the mesophyll conductance. When the assimilatory charge was measured after a short exposure to CO2-free N2, it remained constant at lower temperatures and declined only at superoptimal temperatures. As the assimilatory charge reflects the RuP2 pool in the leaf, the temperature dependence of the mesophyll conductance at a constant assimilatory charge reveals the actual activation energy of the CO2 binding reaction of carboxylase (together with the CO2 transport conductance in the liquid phase of mesophyll cells) which was 29 kJ mol-� for both species. At superoptimal temperatures, the primary cause for the reversible decrease of photosynthesis was a decrease in the assimilatory charge (RuP2 pool). The decrease cannot be caused by an inadequate rate of RuP2 resynthesis but is, presumably, the result of either too rapid drainage of triosephosphates to the cytosol from chloroplasts or de-energisation of thylakoids at high temperatures.
31
Kārkliņa, Katrīna, Gunārs Lācis e Baiba Lāce. "Differences in Leaf Morphological Parameters of Pear (Pyrus communis L.) Based on Their Susceptibility to European Pear Rust Caused by Gymnosporangium sabinae (Dicks.) Oerst." Plants 10, n. 5 (20 maggio 2021): 1024. http://dx.doi.org/10.3390/plants10051024.
Testo completoAbstract (sommario):
European pear rust is an important disease; however, the relationship between its causal pathogen Gymnosporangium sabinae (Dicks.) Oerst. and host Pyrus communis L. is poorly understood. In this study, disease severity was measured, and leaf samples were collected over three years, and their leaf water content; leaf area; leaf mass per area; and epidermis, mesophyll, and vascular tissue width and stomatal density were measured and compared between susceptible and resistant genotypes for each year. Most genotypes either showed consistent disease symptoms or showed no symptoms during the study in terms of their susceptibility. A correlation between disease severity and mesophyll tissue thickness, and stomatal density and differences between several morphological parameters were found depending on the genotype’s susceptibility. The study showed that the following pear morphological traits were stable between the years: water content, leaf mass per area, spongy mesophyll thickness, phloem thickness, and stomatal density. When selecting for breeding, we found that candidates for traits that discern susceptible genotypes from resistant were mesophyll layer width, stomatal density, epidermis width, and xylem tissue width.
32
Kinsman, E. A., e K. A. Pyke. "Bundle sheath cells and cell-specific plastid development in Arabidopsis leaves". Development 125, n. 10 (15 maggio 1998): 1815–22. http://dx.doi.org/10.1242/dev.125.10.1815.
Testo completoAbstract (sommario):
Bundle sheath cells form a sheath around the entire vascular tissue in Arabidopsis leaves and constitute a distinct leaf cell type, as defined by their elongate morphology, their position adjacent to the vein and by differences in their chloroplast development compared to mesophyll cells. They constitute about 15% of chloroplast-containing cells in the leaf. In order to identify genes which play a role in the differential development of bundle sheath and mesophyll cell chloroplasts, a screen of reticulate leaf mutants of Arabidopsis was used to identify a new class of mutants termed dov (differential development of vascular-associated cells). The dov1 mutant clearly demonstrates a cell-specific difference in chloroplast development. Mutant leaves are highly reticulate with a green vascular pattern. The underlying bundle sheath cells always contain normal chloroplasts, whereas chloroplasts in mesophyll cells are abnormal, reduced in number per cell and seriously perturbed in morphology at the ultrastructural level. This demonstrates that differential chloroplast development occurs between the bundle sheath and mesophyll cells in the Arabidopsis leaf.
33
Broschat, Timothy K., Henry Donselman e Dennis B. McConnell. "Light Acclimatization in Ptychosperma elegans". HortScience 24, n. 2 (aprile 1989): 267–68. http://dx.doi.org/10.21273/hortsci.24.2.267.
Testo completoAbstract (sommario):
Abstract Sun-grown (2100 μmol·s-1·m-2) Ptychosperma elegans palms were acclimatized for 0, 1, 2, 3, 4, 6, 8, or 12 months under shade (570 μmol·s-1·m-2). Plant height was greater in palms grown under shade for 6 months or longer and plant color gradually improved when palms were grown under shade for 2 months or longer. Leaves produced under shade had an undifferentiated mesophyll comprised of isodiametric and rectangular cells. Full sun leaves had a mesophyll with distinct palisade cells and abaxial mesophyll cells comprised of rectangular and isodiametric cells. The mesophyll in both light levels had small intercellular spaces. Sun leaves were replaced under shade at a rate of about one leaf every 3 months. After 10 weeks in an interior environment, the number of green leaves remaining on the palms was directly proportional to the number of shade leaves on the plant before placement in the interior environment and to the length of time the palms had been grown under shade.
34
Struck, C., R. Rohringer e R. Heitefuss. "Isolation and lectin-binding properties of barley epidermal and mesophyll protoplasts". Canadian Journal of Botany 72, n. 11 (1 novembre 1994): 1688–91. http://dx.doi.org/10.1139/b94-207.
Testo completoAbstract (sommario):
Protoplasts from primary leaves of barley (Hordeum vulgare L.) were obtained by enzymatic digestion and fractionated by discontinuous density gradient centrifugation to yield highly enriched fractions of mesophyll and epidermal protoplasts. A characterization of both protoplast types resulted in a clear differentiation of the outer protoplast surfaces. The protoplasts were examined for affinity to various lectins by agglutination tests and by labeling with lectin – fluorescein isothiocyanate conjugates. Both types of protoplasts agglutinated with soybean lectin. Fluorescein isothiocyanate-labeled soybean lectin was uniformly distributed on the protoplast surface. Mesophyll protoplasts, but not protoplasts from the epidermis, were agglutinated by Concanavalin A. Both types of protoplasts exhibited fluorescence labeling with Concanavalin A – fluorescein isothiocyanate conjugate. This label often showed a patchy distribution on the protoplast surface. Tetragonolobus lectin and β-D-glucosyl Yariv artificial antigen agglutinated mesophyll but not epidermal protoplasts. One of three tested monoclonal antibodies with specificity for arabinogalactans had affinity to the surface of mesophyll and epidermal protoplasts. Key words: agglutination, arabinogalactan protein, cell surface, epidermal protoplasts, fluorescence labeling, lectin.
35
Lim, Hyoun-Sub, Anna Maria Vaira, Hanhong Bae, Jennifer N. Bragg, Steven E. Ruzin, Gary R. Bauchan, Margaret M. Dienelt, Robert A. Owens e John Hammond. "Mutation of a chloroplast-targeting signal in Alternanthera mosaic virus TGB3 impairs cell-to-cell movement and eliminates long-distance virus movement". Journal of General Virology 91, n. 8 (1 agosto 2010): 2102–15. http://dx.doi.org/10.1099/vir.0.019448-0.
Testo completoAbstract (sommario):
Cell-to-cell movement of potexviruses requires coordinated action of the coat protein and triple gene block (TGB) proteins. The structural properties of Alternanthera mosaic virus (AltMV) TGB3 were examined by methods differentiating between signal peptides and transmembrane domains, and its subcellular localization was studied by Agrobacterium-mediated transient expression and confocal microscopy. Unlike potato virus X (PVX) TGB3, AltMV TGB3 was not associated with the endoplasmic reticulum, and accumulated preferentially in mesophyll cells. Deletion and site-specific mutagenesis revealed an internal signal VL(17,18) of TGB3 essential for chloroplast localization, and either deletion of the TGB3 start codon or alteration of the chloroplast-localization signal limited cell-to-cell movement to the epidermis, yielding a virus that was unable to move into the mesophyll layer. Overexpression of AltMV TGB3 from either AltMV or PVX infectious clones resulted in veinal necrosis and vesiculation at the chloroplast membrane, a cytopathology not observed in wild-type infections. The distinctive mesophyll and chloroplast localization of AltMV TGB3 highlights the critical role played by mesophyll targeting in virus long-distance movement within plants.
36
Delfine, Sebastiano, Arturo Alvino, Massimo Zacchini e Francesco Loreto. "Consequences of salt stress on conductance to CO2 diffusion, Rubisco characteristics and anatomy of spinach leaves". Functional Plant Biology 25, n. 3 (1998): 395. http://dx.doi.org/10.1071/pp97161.
Testo completoAbstract (sommario):
Spinach (Spinacia oleracea L.) leaves stressed by irrigation with water containing 1% (w/v) NaCl for 20 days had low conductance to CO2 diffusion both at the stomata and in the mesophyll. Mesophyll anatomy changed in salt-stressed leaves, which could have accounted for the decreased mesophyll conductance. Ribulose- 1,5-bisphosphate carboxylase/oxygenase in vitro activity and content were not affected by up to 20 days exposure to salinity but decreased when leaves were exposed to salt stress for longer than 20 days. Salt accumulation also caused a drop of Ca and Mg which might have decreased membrane stability and chlorophyll content, respectively. Measurements of chlorophyll fluorescence indicated that the 20-day-long salt stress did not directly affect photochemistry. We conclude that salinity reduces photosynthesis primarily by reducing the diffusion of CO2 to the chloroplast, both by stomatal closure and by changes in mesophyll structure which decreases the conductance to CO2 diffusion within the leaf. The capacity for carbon metabolism is eventually reduced but that occurs after substantial decreases in the conductance to CO2 diffusion.
37
Sajo, Maria das Graças, e Silvia Rodrigues Machado. "Submicroscopical Features of Leaves of Xyris Species". Brazilian Archives of Biology and Technology 44, n. 4 (dicembre 2001): 405–10. http://dx.doi.org/10.1590/s1516-89132001000400011.
Testo completoAbstract (sommario):
The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells.
38
Tsujii, Yuki, Masakazu Oikawa e Kanehiro Kitayama. "Significance of the localization of phosphorus among tissues on a cross-section of leaf lamina of Bornean tree species for phosphorus-use efficiency". Journal of Tropical Ecology 33, n. 3 (maggio 2017): 237–40. http://dx.doi.org/10.1017/s0266467417000141.
Testo completoAbstract (sommario):
Abstract:A greater relative allocation of phosphorus (P) to photosynthetically active cells functions to maintain a rapid photosynthesis under P limitation, and may be a key mechanism of plants to use P efficiently. This mechanism has not been studied in tropical trees despite the productivity of tropical forests often being limited by P. In this study, the spatial distribution of P among tissues on a cross-section of leaf lamina was analysed for 13 tree species from P-limited sites on Mount Kinabalu, Borneo. Most species showed greater P concentration in palisade mesophyll than in spongy mesophyll and epidermal tissues, suggesting that tropical trees under P limitation localize foliar P in photosynthetic palisade mesophyll.
39
Mudalige, Rasika G., Adelheid R. Kuehnle e Teresita D. Amore. "Pigment Distribution and Epidermal Cell Shape in Dendrobium Species and Hybrids". HortScience 38, n. 4 (luglio 2003): 573–77. http://dx.doi.org/10.21273/hortsci.38.4.573.
Testo completoAbstract (sommario):
Perianths of 34 Dendrobium Sw. species and hybrids were examined to elucidate the roles of pigment distribution and shape of upper epidermal cells in determining color intensity, perception, and visual texture. Color intensity was determined by the spatial localization of anthocyanin in tissue layers, i.e., in the epidermal, subepidermal, and mesophyll layers, as well as by distribution of pigmented cells within the tissue layer. Anthocyanins were confined to the epidermal layer or subepidermal layer in flowers with low color intensity, whereas they were also in several layers of mesophyll in more intensely colored flowers. Striped patterns on the perianth were due to the restriction of pigment to cells surrounding the vascular bundles. Color perception is influenced by the presence or absence of carotenoids, which when present, were distributed in all cell layers. Anthocyanins in combination with carotenoids resulted in a variety of flower colors ranging from red, maroon, bronze to brown, depending on the relative location of the two pigments. Four types of epidermal cell shapes were identified in Dendrobium flowers: flat, dome, elongated dome, and papillate. Epidermal cell shape and cell packing in the mesophyll affected the visual texture. Petals and sepals with flat cells and a tightly packed mesophyll had a glossy texture, whereas dome cells and loosely packed mesophyll contributed a velvety texture. The labella in the majority of flowers examined had a complex epidermis with more than one epidermal cell shape, predominantly papillate epidermal cells.
40
Liu, Youqi, e Nancy G. Dengler. "Bundle sheath and mesophyll cell differentiation in the C4 dicotyledon Atriplex rosea: quantitative ultrastructure". Canadian Journal of Botany 72, n. 5 (1 maggio 1994): 644–57. http://dx.doi.org/10.1139/b94-085.
Testo completoAbstract (sommario):
In leaves of most C4 species, both bundle sheath and mesophyll cells are derived from ground meristem, yet at maturity differ in photosynthetic enzyme complement and in cell size, shape, and subcellular ultrastructure. This quantitative ultrastructural study of bundle sheath and mesophyll cell differentiation in Atriplex rosea shows that while developmental pathways of bundle sheath and meosphyll cells are generally coordinated, the timing of developmental divergence differs among individual characteristics. For instance, bundle sheath cells are larger, with more chloroplasts and more and larger mitochondria by 8 days after leaf emergence, while differential growth of mesophyll cell chloroplast peripheral reticulum and increase in thylakoids per granum in bundle sheath chloroplasts do not develop until after 12 days. Multigroup principal components analysis (M-PCA) of the data emphasizes that the greatest source of variation is overall size change as both cell types expand. M-PCA also identifies patterns of allometry within the data; for instance, mesophyll cell vacuoles and chloroplast peripheral reticulum undergo greater relative growth than do bundle sheath microbody area and number. The greater structural specialization of bundle sheath cells is reflected in higher growth rates from the time of divergence, but developmental change in both cell types continues until leaf expansion is complete. Most structural changes occur substantially after the stage of cell-specific expression of C4 enzymes. Key words: bundle sheath, mesophyll, C4 photosynthesis, leaf development, Atriplex rosea, multigroup principal components analysis.
41
Ecevit Genç, Gülay, Betül Büyükkılıç Altınbaşak, Taner Özcan e Tuncay Dirmenci. "Comparative anatomical studies of some Teucrium sect. Teucrium species: Teucrium alyssifolium Stapf, Teucrium brevifolium Schreb. and Teucrium pestalozzae Boiss. (Lamiaceae)". PhytoKeys 96 (3 aprile 2018): 63–77. http://dx.doi.org/10.3897/phytokeys.96.24498.
Testo completoAbstract (sommario):
Teucriumalyssifolium Stapf (endemic), Teucriumpestalozzae Boiss. (endemic) and Teucriumbrevifolium Schreb. are three closely related taxa in Teucriumsect.Teucrium. The obtained data from the anatomical studies revealed that these three taxa represent the general anatomical characteristics of the Lamiaceae family. Leaves, anatomical features such as thick cuticle, abundant trichomes, rich palisade parenchyma layer in the mesophyll provide evidence that these three species are xeromorphic structures. Leaf and stem anatomy showed that the taxa have generally similar anatomical features. However, cuticle layers, epidermis cells size, indumentum density, mesophyll types, palisade parenchyma occupied in the mesophyll, presence of spherocrystals in leaves and parenchyma, collenchyma and sclerenchyma layers in stems show differences amongst the taxa. Anatomical characters of leaf and stem of these taxa are examined for the first time in this study.
42
McHale, N. A., e M. Marcotrigiano. "LAM1 is required for dorsoventrality and lateral growth of the leaf blade in Nicotiana". Development 125, n. 21 (1 novembre 1998): 4235–43. http://dx.doi.org/10.1242/dev.125.21.4235.
Testo completoAbstract (sommario):
The role of LAM1 in dorsoventrality and lateral growth of the leaf blade was investigated in the ‘bladeless’ lam1 mutant of Nicotiana sylvestris and in periclinal chimeras with lam1 and wild-type (N. glauca) cell layers. Mutant lam1 primordia show normal dorsoventrality at emergence, but produce blade tissue that lacks dorsal cell types and fails to expand in the lateral plane. In leaves of a lam1-glauca-glauca (L1-L2-L3) chimera, we observed restoration of dorsal identity in the lam1 upper epidermis, suggesting non-cell-autonomous movement of a dorsalizing factor between cell layers of the blade. A lam1-lam1-glauca chimera generated a leaf blade with lam1 cells in the L1-derived epidermis and the L2-derived upper and lower mesophyll. An in situ lineage analysis revealed that N. glauca cells in the L3-derived middle mesophyll restore palisade differentiation in the adjoining lam1 upper mesophyll. Movement of dorsalizing information appears short-range, however, having no effect on the upper lam1 epidermis in lam1-lam1-glauca. Clusters of lam1 mesophyll in distal or proximal positions show a localized default to radial growth, indicating that the LAM1 function is required for dorsoventrality and lateral growth throughout blade expansion.
43
Migalina, S. V., L. A. Ivanov e L. A. Ivanova. "Changes in sizes of mesophyll cells underlies the adaptation of Betula platyphylla Sukacz. leaf to increased climate aridity". Проблемы ботаники Южной Сибири и Монголии 21, n. 1 (6 giugno 2022): 113–16. http://dx.doi.org/10.14258/pbssm.2022024.
Testo completoAbstract (sommario):
Climate changes in Central Asia attract increasing attention to studies in successions, ecosystem transformations and plant adaptation. Functional mechanisms of plant adaptation are related to the changes in leaf structure, first of all, the architecture of carbon-assimilating tissues. We studied leaf mesophyll structure of Betula platyphylla Sukacz. from geographical regions in the southern part of East Siberia and Mongolia with different climate aridity. Birch populations represented a latitudinal range from the middle taiga to the forest-steppe. According our results changes in mesophyll structure occurred along the aridity gradient, which manifested in a significant decrease (by 38-40 %) in cell sizes and an increase in surface area and volume ratio of mesophyll. Such rearrangement of mesophyll structure provides a higher rate of intraleaf diffusion of CO2 and the maintenance of high level of photosynthesis under water deficiency. We concluded that changes in the sizes of carbon-assimilating cells which underlies the restructuring of leaf three-dimensional organization provides regulation of gas exchange, and is a key mechanism for the adaptation of the photosynthetic function of Betula platyphylla to increased aridity of the climate.
44
Zakariyya, Fakhrusy, Didik Indradewa e Teguh Iman Santoso. "Changes of leaf anatomical profile of cocoa clones seedlings in response to drought." Pelita Perkebunan (a Coffee and Cocoa Research Journal) 35, n. 3 (31 dicembre 2019): 177–85. http://dx.doi.org/10.22302/iccri.jur.pelitaperkebunan.v35i3.390.
Testo completoAbstract (sommario):
Cocoa is a plant that is very sensitive to drought during its growth and development phase, which causes changes up to the anatomical and morphologicallevel. This research is aimed to examine the changes on several leaf anatomical characteristics of three cocoa clones under the drought stress. This research was conducted in a greenhouse of Indonesian Coffee and Cocoa Research Institute, Jember, East Java, Indonesia in January – December 2017. The research was designedusing randomized complete block design with two factors including clones and watering time interval, with three replications. The clone factor comprised of ICS 60,KW 641, and Sulawesi 1. The result showed that the clones of Sulawesi 1 and KW 641 cocoa had a higher mesophyll thickness, lower stomatal density, narrowerstomatal opening, thicker abaxial and adaxial epidermis, and higher relative water content compared to ICS 60 clone. The 8-day watering interval caused a decreasein mesophyll thickness, leaf thickness, increase in stomatal density, stomatal closure, decrease in abaxial epidermis thickness, and decrease in water status within the plant tissue. The thicker the leaf mesophyll tissue, the higher the leaf water content was. This showed that the water status within a plant leaf tissue determined bythe leaf mesophyll thickness.
45
Kwon, Hye Jin, Song Kwon e Ki Sun Kim. "140 Ultrastructural Changes during the Senescence of Petals in Hibiscus syriacus L." HortScience 35, n. 3 (giugno 2000): 413E—413. http://dx.doi.org/10.21273/hortsci.35.3.413e.
Testo completoAbstract (sommario):
Five distinctive developmental stages were chronologically suggested. Cells at Stage I and II were essentially free of cytoplasmic or vacuolar abnormalities and the cytoplasm contained numerous electron-dense mitochondria with well-developed cristae. At Stage III, there were a localized dilation of mitochondria matrix and a partial-diluted cytoplasm in mesophyll cells. At Stage IV, characterized by high levels of fresh weight and osmolality, most mesophyll cells were seen to be ruptured, resulting in a general mixing of cell contents and diluting cytoplasm. It can be explained as an irreversible senescence phenomena that tonoplast in mesophyll cell was ruptured partly, corresponding to rapid increase in petal cell size and turgidity. Petal turgidity was due to an increase of content in soluble sugar. At Stage V, there was a loss of petal fresh weight. With a loss of turgidity, most mesophyll cells have collapsed completely. There were a notable plasmolysis in vasculature. The activity of protease in petals was found to increase between Stage II and III, and then decreased rapidly at Stage IV, resulting in the decrease of total protein content before senescence. Unexpectedly, there were stomata in hibiscus petals. Ultrastructural disorganization, like as a broken tonoplast, was observed in mesophyll cells at Stage IV. ABA and the stomata on petal might promote the disorganization. The final stages of senescence involved breakdown of cellular organization leading to hydrolysis of previously separated compartments. The cellular disorganization triggered during the flowers are still in the process of opening may be one of the earliest physiological signal that senescence is under way.
46
Kubínová, Zuzana, Natália Glanc, Barbora Radochová, Zuzana Lhotáková, Jiří Janáček, Lucie Kubínová e Jana Albrechtova. "UNBIASED ESTIMATION OF NORWAY SPRUCE (PICEA ABIES L. KARST.) CHLOROPLAST STRUCTURE: HETEROGENEITY WITHIN NEEDLE MESOPHYLL UNDER DIFFERENT IRRADIANCE AND [CO2]". Image Analysis & Stereology 38, n. 1 (11 aprile 2019): 83. http://dx.doi.org/10.5566/ias.2005.
Testo completoAbstract (sommario):
The main objective of this study was to find out whether the selected chloroplast characteristics measured in the mesophyll layer nearest to the needle surface (i.e., the first mesophyll layer) could be representative for the whole needle cross section. Two chloroplast sampling approaches were applied on Norway spruce needles during the investigation of the effects of different levels of air CO2 concentration and irradiance: (i) sampling only from the first mesophyll layer, and (ii) systematic uniform random (SUR) sampling. The selected characteristics were: (i) chloroplast area, (ii) starch grain area, and (iii) starch areal density on median chloroplast cross sections, and (iv) chloroplast number per unit of needle volume. It was shown that the first mesophyll layer was not representative for estimating all evaluated characteristics except the chloroplast area. Sampling only there caused obtaining slightly biased results, while SUR sampling gave unbiased estimations at the cost of longer measuring time. The major effect of studied factors was in starch areal density and starch grain area, which were larger in sun needles in elevated CO2 concentration in comparison with sun needles in ambient CO2 concentration. In conclusion, it was demonstrated that the first layer of mesophyll is not always representative for the needle cross section. If technically feasible, SUR is recommended for analysis of chloroplast ultrastructure. The simplified sampling design can be applied, e.g., for comparisons of many different treatments. However, it should be combined with other approaches to characterize the chloroplast function and the results carefully considered and interpreted.
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Han, Shijuan, Stephen C. Maberly, Brigitte Gontero, Zhenfei Xing, Wei Li, Hongsheng Jiang e Wenmin Huang. "Structural basis for C4 photosynthesis without Kranz anatomy in leaves of the submerged freshwater plant Ottelia alismoides". Annals of Botany 125, n. 6 (16 gennaio 2020): 869–79. http://dx.doi.org/10.1093/aob/mcaa005.
Testo completoAbstract (sommario):
Abstract Background and Aims Ottelia alismoides (Hydrocharitaceae) is a freshwater macrophyte that, unusually, possesses three different CO2-concentrating mechanisms. Here we describe its leaf anatomy and chloroplast ultrastructure, how these are altered by CO2 concentration and how they may underlie C4 photosynthesis. Methods Light and transmission electron microscopy were used to study the anatomy of mature leaves of O. alismoides grown at high and low CO2 concentrations. Diel acid change and the activity of phosphoenolpyruvate carboxylase were measured to confirm that CAM activity and C4 photosynthesis were present. Key Results When O. alismoides was grown at low CO2, the leaves performed both C4 and CAM photosynthesis whereas at high CO2 leaves used C4 photosynthesis. The leaf comprised an upper and lower layer of epidermal cells separated by a large air space occupying about 22 % of the leaf transverse-section area, and by mesophyll cells connecting the two epidermal layers. Kranz anatomy was absent. At low CO2, chloroplasts in the mesophyll cells were filled with starch even at the start of the photoperiod, while epidermal chloroplasts contained small starch grains. The number of chloroplasts in the epidermis was greater than in the mesophyll cells. At high CO2, the structure was unchanged but the thicknesses of the two epidermal layers, the air space, mesophyll and the transverse-section area of cells and air space were greater. Conclusions Leaves of O. alismoides have epidermal and mesophyll cells that contain chloroplasts and large air spaces but lack Kranz anatomy. The high starch content of mesophyll cells suggests they may benefit from an internal source of CO2, for example via C4 metabolism, and are also sites of starch storage. The air spaces may help in the recycling of decarboxylated or respired CO2. The structural similarity of leaves at low and high CO2 is consistent with the constitutive nature of bicarbonate and C4 photosynthesis. There is sufficient structural diversity within the leaf of O. alismoides to support dual-cell C4 photosynthesis even though Kranz anatomy is absent.
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Belaeva, T. N., e A. N. Butenkova. "Leaf blade anatomy of the rare Siberian flora species Mertensia sibirica (L.) G. Don fil. (Boraginaceae)". Ukrainian Journal of Ecology 10, n. 5 (20 ottobre 2020): 186–91. http://dx.doi.org/10.15421/2020_228.
Testo completoAbstract (sommario):
The authors present the findings of a leaf blade anatomy study for the rare relict Siberian flora species Mertensia sibirica (L.) G. Don fil. (Boraginaceae). They collected samples for the study from natural habitats in Chita Region (Chikoy Range) and then planted them in the introduction area of the Siberian Botanic Garden (Tomsk) located in the southern taiga subzone of Western Siberia. The parameters of the photosynthetic and stomatal complex of M. sibirica were studied for the first time. It was found out that the rosette and cauline leaves of the species under study are hypostomatous, with an anomocytic stomatal complex. The epidermis is single-layer. On average, the adaxial epidermis has larger cells vs. abaxial epidermis. The leaf mesophyll is 242.90–369.90 µm thick, dorsiventral. The adaxial side of the leaf comprises glandular trichomes surrounded with pronounced rosettes of cells in the base part. The cauline leaf significantly differs from the rosette leaf in finer cells of its adaxial and abaxial epidermis (and, consequently, their larger number per 1 mm2), while the adaxial epidermal cells are thicker, and in a larger number of stomata in the abaxial epidermis. The palisade mesophyll in the cauline leaf is more developed vs. the rosette leaf, while the cells are longer and the palisade/spongy mesophyll ratio is higher. The rosette leaves have a more developed system of vascular tissues vs. cauline ones, as they play the main role in providing plants with water and nutrients. The contribution of the cauline leaf palisade mesophyll to the photosynthetic potential of M. sibirica is higher vs. that of the rosette leaf (the ratio between palisade and spongy mesophyll is 0.45 vs. 0.36, respectively), which characterizes the cauline leaf as more heliophytic. The stomatal complex and mesophyll parameters under study are primarily characterized by low variance. As for dermal tissue parameters, medium variance is typical of the thickness and size of the abaxial and adaxial epidermal cells. Coefficients of variation for the cells of the upper mesophyll layer (CV=31.2–41.6%) and the number of stomata on the lower epidermis of the rosette leaf (CV=21.5%) demonstrate medium and high variance. A very high coefficient of variation (116.2–174.0) is registered for the adaxial epidermis parameter characterizing the density of trichomes per 1 mm2. The study results were used to develop an optimal M. sibirica cultivation regime under conditions of introduction in the southern taiga subzone of Western Siberia.
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IIDA, Asako, Hiromichi MORIKAWA e Yasuyuki YAMADA. "Culture of isolated tobacco mesophyll cells." Plant tissue culture letters 6, n. 3 (1989): 169–71. http://dx.doi.org/10.5511/plantbiotechnology1984.6.169.
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Borsuk, Aleca M., Adam B. Roddy, Guillaume Théroux‐Rancourt e Craig R. Brodersen. "Structural organization of the spongy mesophyll". New Phytologist 234, n. 3 (15 febbraio 2022): 946–60. http://dx.doi.org/10.1111/nph.17971.
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