番茄YFT3(YELLOW-FRUITED TOMATO 3)基因在果色发育过程中遗传功能解析

番茄（S.lycopersicum）果色是决定商业属性的外观品质，与品质形成密切相关。聚焦乙烯调控和类胡萝卜素合成果色发育研究已很深入，而精准特别是跨途径调控机制还不清楚。研究yft3发现：YFT3 allele遗传损伤番茄红素下降60%，变为黄果。YFT3是MEP途径限速酶并催化IPP和DMAPP异构。PCS前体GGPP源自MEP途径，PCS黄质醛是ABA合成前体，ABA调控乙烯和PCS合成影响果色形成。因而揭示YFT3跨途径调控PCS分子机制有助于对果色发育科学理解。为此，本项目通过亚细胞定位和功能互补明确YFT3遗传学功能；构建差异表达YFT3及不同ABA和C2H4水平番茄，解析MPEA功能及互作模式；结合转录组水平YFT3 allele 损伤影响KEGGs途径挖掘。以期揭示YFT3跨途径调控果色发育和MPEA互作分子机制，有助于理解番茄果色形成调控网络和为番茄品质改良提供理论依据。

Fruit color is a pivotal appearance quality, which is deciding the commercial attributes in Solanum lycopersicum. Formation of the fruit color is determined by components and contents of carotenoids, and was extensively concerned on both responses to ethylene signal and carotenoids biosynthesis. However, the precisely regulated mechanism of fruit color formation in tomato had still remained elusive so far. As researched tomato mutant of the yellow-fruited tomato 3 (yft3), we found that a missense mutation (A+2116 to C +2116) in the isolated YFT3 allele from yft3 by map-based cloning approach caused reduce 60 % of lycopene content, and as a result of the yellow-fruited tomato phenotype. SlIDI1(Isopentenyl-diphosphate delta isomerase 1 in S.lycopersicum ), as the candidate gene of the YFT3, the YFT3 protein is a rate-limited enzyme in MEP (Methylerythritol 4-phosphate) pathway, as well as biosynthesis of terpenoid and terpene derivatives in the plant kingdom, and which catalyzes reversible allosteric between IPP (isopentenyl diphosphate) and DMAPP(dimethylallyl diphosphate). The GGPP(geranylgeranyl pyrophosphat) derived from MEP pathway acts the precursor for pathway of the carotenoid synthesis(PCS), xanthoxin produced from PCS serves as the precursor for ABA biosynthesis, and ABA affacts fruit color formation throught regulation of both ethylene and carotenoids biosyntheis. Therefor, rrevealing of the genetic mechanism that YFT3 regulates PCS, but beyond the MEP pathway has an important bearing on the scientific understanding of the fruit color formation. For this, in the project, the techniques of subcellular localization and functional complementation would be employed to confirm genetic functions of the YFT3. A serial of tomato variations with the differently expressed YFT3 gene or differenced levels of ABA and C2H4 would be constructed to dissect MPEA (MEP; PCS, pathway of the carotenoids synthesis; ESP, ethylene synthesis pathway; and ABA, abscisic acid synthesis) functions and the interactive models. Mine the KEGGs (Kyoto Encyclopedia of Genes and Genomes) pathways which enrich the differently expressed genes (DEGs) caused from the genetic lesion of the YFT3 allele. Finally, reveal the molecular mechanisms of both YFT3 regulation and MPEA interaction duration of the fruit color development in tomato. The present project would be conducive to deeply understand for molecular regulation mechanism of the fruit color formation and provide theoretical reference for precise improvement of tomato qualities.