YFT1（YELLOW FRUIT TOMATO 1）基因调控番茄果实成熟变软分子机制研究

硬度是番茄（S.lycopersicum）品质和经济性状的重要指标，取决于细胞初生壁特征和膨压。我们前期研究发现，yft1（yellow fruit tomato 1）果实变硬主要归因于初生壁改变。植物初生壁形态建成研究还不够深入并主要聚焦于拟南芥下胚轴，番茄果实独特发育模式，果实硬度决定因子初生壁建成的精准调控分子机制还不清楚。基于此，我们在图位克隆YFT1和转录组分析基础上，本项目通过设计乙烯处理实验、创制番茄不同遗传型（突变体、过表达和 yft1 OEs），分析不同遗传背景GTPTs（genes associated the primary cell wall of tomato fruit）表达和遗传表型（硬度、超微结构和化学组分）变化，明确YFT1调控GTPTs表达模式、对遗传表型影响及YFT1与GTPTs遗传调控上、下游关系；以期揭示YFT1调控番茄果实变软分子机制。

Fruit firmness is an important index of production quality and economical value in tomato (Solanum lycopersicum), and the firmness was determined by both properties of the primary cell wall and cell turgor. Through previously investigated, we realized that compared with cv.M82 (wild tomato), the hardened fruit in mutant yft1（yellow fruit tomato 1）attributed to variation of the primary cell wall. So far, the studies on morphogenesis of the primary cell wall were insufficiency in plant kingdom, and most of them focused on the hypocotyl in Arabidopsis thaliana. However, the of the tomato fruit with uniqueness development pattern was distinctive different to Arabidopsis thaliana, thus the formation of the primary cell wall to be precise regulation in tomato fruit has remained elusive. Based on the previously researched data including map-based cloning of the YELLOW FRUIT TOMATO 1 (YFT1) and transcriptome analysis in our Lab, design an experiment ethylene treatment, and create the different genetic type tomatoes including mutants, over expression, and over expression(OE) in yft1 background(yft1 OEs). And then the expression of genes associated the primary cell wall of tomato fruit (GTPTs）consisting of SLCEL2、SLCESA6、SLPL and SLEXP1 were analyzed by RT-qPCR technique. Varieties of genetic phenotypes which containing fruit firmness, ultrastructure and chemical compositions consisting of cellulose, hemi-cellulose, pectin and contractual proteins were detected by texture analyzer, semi-quantitative method and HPLC. The expression profile of the GTPTs (SLCEL2、SLCESA6、SLPL and SLEXP1) regulated by YFT1 and changes of the genetic phenotypes would be further dissected in the present proposal. The genetics relationship of upper and follower stream between the YFT1 and GTPTs would be also clarified explicitly. Aim of the project is to reveal mechanism of the fruit softening during mature development in tomato, and would provide important theory evidences for coming improvement of the tomato qualities.