黄瓜果实形态建成的遗传和发育机制

Cucumber is the most important vegetable for production in greenhouse in China. The morphological characters of fruit in cucumber are external quality traits, and also important factors affecting yield. In comparison to other fruit-bearing crops, cucumber fruit develops at a very high speed, thus it can be a good system for studying fast development of fruit. Therefore, the investigation of cucumber fruit development is very important for both theory and application. At present, the physiological and cell biological bases of cucumber fruit development have been revealed partially, and a few of candidate genes related to the developing progress are identified. However, the genetic and developmental mechanisms have not been explored comprehensively, and no key gene has been cloned. To facilitate the study of cucumber fruit development, we obtained a number of plant materials including mutants, segregating and natural populations, and a huge amount of data about genome, transcriptome and variome. Also we developed a series of methods to isolate the trait genes by combing the big data and molecular biology. Here, we propose to conduct the below three analyses for investigating the genetic and developmental bases comprehensively. 1) Exploring the profiles of gene expression, cell division, and cell expansion during the fruit development; 2) Isolating and validating genes controlling the morphological traits; 3) Revealing the gene network of regulating fruit development. The expected results of this project will provide the basis for breeding new cucumbers with high yield and good external quality, and are valuable for the study of fruit development in other cucurbits.

黄瓜是我国设施栽培第一大蔬菜，其果实形状既是重要的商品品质性状，也是产量的重要影响因素。黄瓜膨大速度快，是研究果实快速发育的优良系统。因此研究黄瓜果实形态建成具有重要的理论和应用价值。黄瓜果实形态建成的生理过程和细胞学机理已有一定积累，参与基因也有初步探索，但缺乏全面系统的遗传和发育机制研究，还未有关键基因克隆报道。前期研究本团队已经积累了与果实形态相关突变体、分离群体、以及自然群体等多份材料，产生了黄瓜基因组、转录组、变异组等大量数据，并探索了把组学数据与分子生物学相结合快速克隆功能基因的方法论。本项目拟对黄瓜果实形态建成进行全面系统的基因表达和细胞发育机制研究，挖掘黄瓜果实形态快速建成的重要功能基因，克隆果实形态关键基因，解析果实形态建成的遗传调控网络。本项目的研究成果将为培育高产优质黄瓜品种奠定理论基础，并对研究其它瓜类作物果实发育具有重要的参考价值。

葫芦科作物的果实属于瓠果，在我国蔬菜和水果生产中占有非常重要的地位。果实生长决定产量和商品品质；瓠果具有极端多样的果实形态，相比番茄等浆果而言，其果实形态建成的分子机制仍不清楚。本项目利用与果实形态相关突变体、分离群体、以及自然群体等多份材料，产生了黄瓜基因组、转录组、变异组等大量数据，首次揭示了，乙烯剂量依赖的黄瓜果实伸长的遗传和分子机制；组蛋白去乙酰化表观修饰通过调控多个激素（包括乙烯）关键基因，精确控制细胞分裂和黄瓜果实伸长的分子机制；m6A修饰调控黄瓜驯化选择变长的表观转录调控机制。这些研究进展为理解葫芦科果实形态建成的遗传和分子基础提供了重要的信息，在生产上该研究成为黄瓜果实大小的改良育种提供科学基础。