Academic literature on the topic 'SlTCP12'

Potassium deficiency confines root growth and decreases root-to-shoot ratio, thereby limiting root K+ acquisition. This study aimed to identify the regulation network of microRNA319 involved in low-K+ stress tolerance in tomato (Solanum lycopersicum). SlmiR319b-OE roots demonstrated a smaller root system, a lower number of root hairs and lower K+ content under low-K+ stress. We identified SlTCP10 as the target of miR319b using a modified RLM-RACE procedure from some SlTCPs’ predictive complementarity to miR319b. Then, SlTCP10-regulated SlJA2 (an NAC transcription factor) influenced the response to low-K+ stress. CR-SlJA2 (CRISPR-Cas9-SlJA2) lines showed the same root phenotype to SlmiR319-OE compared with WT lines. OE-SlJA2(Overexpression-SlJA2) lines showed higher root biomass, root hair number and K+ concentration in the roots under low-K+ conditions. Furthermore, SlJA2 has been reported to promote abscisic acid (ABA) biosynthesis. Therefore, SlJA2 increases low-K+ tolerance via ABA. In conclusion, enlarging root growth and K+ absorption by the expression of SlmiR319b-regulated SlTCP10, mediating SlJA2 in roots, could provide a new regulation mechanism for increasing K+ acquisition efficiency under low-K+ stress.

Summary The complexity of compound leaves results primarily from the leaflet initiation and arrangement during leaf development. However, the molecular mechanism underlying compound leaf development remains a central research question. SlTCP24 and SlTCP29, two plant‐specific transcription factors with the conserved TCP motif, are shown here to synergistically regulate compound leaf development in tomato. When both of them were knocked out simultaneously, the number of leaflets significantly increased, and the shape of the leaves became more complex. SlTCP24 and SlTCP29 could form both homodimers and heterodimers, and such dimerization was impeded by the leaf polarity regulator SlAS2, which interacted with SlTCP24 and SlTCP29. SlTCP24 and SlTCP29 could bind to the TCP‐binding cis‐element of the SlCKX2 promoter and activate its transcription. Transgenic plants with SlTCP24 and SlTCP29 double‐gene knockout had a lowered transcript level of SlCKX2 and an elevated level of cytokinin. This work led to the identification of two key regulators of tomato compound leaf development and their targeted genes involved in cytokinin metabolic pathway. A model of regulation of compound leaf development was proposed based on observations of this study.

Phytophthora spp. secrete vast arrays of effector molecules during infection to aid in host colonization. The CRN protein family forms an extensive repertoire of candidate effectors that accumulate in the host nucleus to perturb processes required for immunity. Here, we show that CRN12_997 from P. capsici binds a TCP transcription factor, SlTCP14-2, to inhibit its immunity-associated activity against Phytophthora. Co-immuno-precipitation and split-YFP studies confirm a specific CRN12_997-SlTCP14-2 interaction in vivo. Co-expression of CRN12_997 specifically counteracts the TCP14-enhanced immunity phenotype, suggesting CRN mediated perturbation of SlTCP14-2 function. We show that SlTCP14-2 associates with nuclear chromatin and that CRN12_997 diminishes SlTCP14-2 DNA-binding. Collectively, our data support a model in which SlTCP14-2 associates with chromatin to enhance immunity. The interaction between CRN12_997 and SlTCP14-2 reduces DNA-binding of the immune regulator. We propose that the modulation of SlTCP14-2 chromatin affinity, caused by CRN12-997, enhances susceptibility to Phytophthora capsici.

Les changements morphologiques et métaboliques liés à la maturation des fruits impliquent une reprogrammation de l’expression de nombreux gènes codant différents types d’effecteurs, laquelle est orchestrée par l’action simultanée de nombreux régulateurs. Cependant, les mécanismes moléculaires qui sous-tendent la transition de couleur restent mal compris.Dans le chapitre I, je présente une introduction bibliographique pour passer en revue l'état de l'art dans le domaine de la transition chloroplaste à chromoplaste et décrire les changements structurels, physiologiques et protéiques qui se produisent au cours de la transition; enfin, je présenterai les fonctions et donnée connues sur la famille SlTCP.Les chapitres II et III suivants constituent le contenu principal de notre article en préparation et à venir. Sur la base des données d'expression dans les tomates, j'ai découvert que SlTCP12, SlTCP15, SlTCP18 et SlTCP27 sont les seuls isoformes de TCP à expression élevée pendant la maturation. Nous avons initié notre étude sur SlTCP12. Nous avons vérifié que le facteur de transcription codé par SlTCP12 fonctionne comme un activateur de transcription et est exclusivement localisé dans le noyau. Le gène présente une augmentation substantielle de son expression à partir du stade vert mature, laquelle se poursuit dans les stades ultérieurs (Breaker, Orange, Red). Pour étudier le rôle de SlTCP12, j'ai construit des plantes TCP12-KO en utilisant des approches CRISPR/Cas9 et analysé son phénotype sur la génération homozygote. Mes résultats suggèrent que l'absence de SlTCP12 entraîne des altérations de la couleur du péricarpe du fruit, le mutant présentant un phénotype de Yellow Shoulder (coloration jaune au niveau de la base du fruit) qui demeure sensible à certains facteurs environnementaux. Afin d'obtenir un modèle des voies de régulation impliquant SlTCP12, nous avons combiné des approches de biochimie, de biologie cellulaire et moléculaire et montré que SlTCP12 n’agit pas directement sur la synthèse des chlorophylles, mais qu’il influence surtout la transition des chloroplastes en chromoplastes. Nous avons notamment démontré l’action directe de SlTCP12 sur les promoteurs des gènes SlPSY1/PSY2. Enfin, en amont, nous avons pu montrer, par analyse transcriptomique de différents mutants et par l’utilisation du système Dual-luciférase, l’existence d’une régulation de l’expression de SlTCP12 par les régulateurs SlGLK2 et RIN.Le chapitre (IV) s’intéresse à l’action simultanée, et potentiellement redondante des différents isoformes de TCP exprimés lors de la maturation. Sur la base des données d'expression chez la tomate, j'ai découvert que SlTCP12, SlTCP15 et SlTCP18 sont les seuls gènes à forte expression pendant la maturation. J'ai conçu et initié diverses constructions pour générer différentes plantes avec une expression altérée des trois gènes TCP12, TCP15 et TCP18, en utilisant des approches CRISPR/Cas9. Ainsi, des lignées de tomates portant le triple KO sur SlTCP12, SlTCP15 et SlTCP18 ont été obtenues, son phénotype étant analysé sur la génération T3. A partir des premiers résultats, le triple mutant SLTCP12/15/18 présente un phénotype semblable au simple mutant SlTCP12 (phénotype de yellow shoulder, concentrations plus élevées de chlorophylles et de sucres solubles), avec une sévérité très légèrement accrue, ce qui suggère une redondance très partielle entre les trois isoformes. De plus, de nombreux gènes liés à la maturation et aux modifications de coloration affectés dans le simple mutant SlTCP12 voient aussi leur expression altérée dans le triple mutant SlTCP12/15/18, c’est le cas notamment de FUL1, FUL2 et TAGL1, parfois à des niveaux importants ce qui suggère aussi des actions spécifiques de SlTCP15 et SlTCP18 dans la maturation du fruit de tomate.Dans l’ensemble, notre étude révèle le rôle important de SlTCP12 dans la régulation de la couleur des fruits et la sensibilité aux facteurs environnementaux
Fleshy fruits are major sources of necessary nutrients in many people’s diets around the world, and their ripening is a complex physiological and biochemical process that involves the coordinated regulation of numerous physiological and biochemical changes that determine flavor, color, texture, and aroma. These changes involve the up- or downregulation of numerous genes in various metabolic pathways. However, the molecular mechanisms underlying the color transition remain poorly understood.In Chapter I, I introduce of tomato, which is an important model species for fleshy fruit research and a reference species for the Solanaceae family. Then, I provide a bibliographic introduction to review the state of the art in the field of chloroplast to chromoplast transition, describing the structural, physiological, and protein structure changes that occur during this transition. Lastly, I introduce the functions of SlTCPs in plant and fruit development, which will be valorized with a submitted review.The following chapters II and III are the core content of our forthcoming article. Based on expression data in tomatoes, I found that SlTCP12, SlTCP15, SlTCP18 and SlTCP27 are the only genes with high expression during ripening. Notably, SlTCP12, functioning as a transcription activator and exclusively localized within the nucleus, displays a substantial increase in expression starting from the mature green stage and continuing beyond it. To investigate the role of SlTCP12, I constructed TCP12-KO plants using CRISPR/Cas9 approaches and analyzed their phenotype in the homozygous generation. My findings suggest that the absence of SlTCP12 leads to alterations in fruit pericarp color, with the mutant displaying a yellow shoulder phenotype that exhibits sensitivity to certain environmental factors. In order to uncover the regulatory pathway of SlTCP12 action, we employed a series of methods at the cellular, biochemical, and molecular levels, and demonstrated that SlTCP12 does not affect chlorophyll synthesis but rather influences chloroplast degradation and the conversion into chromoplasts, leading to the yellow shoulder phenotype. We also validated that SlTCP12 exerts its regulation by directly binding to SlPSY1/SlPSY2 promoter regions, thereby governing the development and transition of chloroplasts and chromoplasts in tomatoes. Furthermore, SlGLK2 and RIN can directly interact with the promoter region of SlTCP12, as suggested by transcriptome analyses of RIN-KO mutant and Dual-Luc assays.The last chapters IV aims at enlarging the work to SlTCP12 homologues. Based on expression data in tomato, I found that SlTCP12, SlTCP15, SlTCP18 are the only genes with high expression during ripening. I designed and initiated diverse constructs to generate different plants with SlTCP12, SlTCP15 and SlTCP18 altered expression using CRISPR/Cas9. Thus, tomato lines bearing the triple KO on SlTCP12, SlTCP15 and SlTCP18 have been obtained, and their phenotypes have been analyzed in the T3 generation. According to the first results, triple SlTCP12/15/18 mutant displays the phenotype similar to SlTCP12 single mutant (occurrence of yellow shoulder in DPH14 fruit and high level of chlorophyll and soluble sugar) with a mild increase in phenotype severity, suggesting a partial, but limited redundancy between the three TCP isoforms. In addition, in the triple SlTCP12/15/18 mutant, we observed modifications in the expression of several genes related to ripening and color changes, exhibiting alterations consistent with those observed in tcp12, such as FUL1, FUL2, and TAGL1. These changes were obviously more pronounced than in tcp12, suggesting that SlTCP15 and SlTCP18 may have special functions in tomato ripening.Taken together, our study reveals the important role of SlTCP12 in fruit color regulation and sensitivity to environmental factors