拟南芥UBP14调控种子大小分子机理的研究

Seed size is one of key agronomic traits. How plants determine their seed size is also a fascinating question in developmental biology. It is significant to understand the molecular mechanisms in controlling seed size. However, the determination of seed size is almost unknown in plants. The UBP14, which encodes a de-ubiquitinase protein in Arabidopsis, serves as a negative regulator of cell proliferation and boosts the development of embryo to control seed size, the ubp14 mutant forms larger seeds, and reciprocal cross experiments showed that UBP14 acts maternally to curb seed growth. While the molecular mechanisms of UBP14 in regulating seeds size are largely unknown. In this proposal, a combination of biochemical, genetic, cytological and molecular biological methods will be used to screen UBP14 interacting proteins and downstream regulators, to reveal new genes involved seed size control, to build up a genetic framework for UBP14 mediating control of seed size and to define a novel genetic and molecular mechanism involving the UBP14 to control seed size. This study will expand the theory of seed size control，and also provide the resources of gene in yield improvement.

植物的种子大小是重要的农艺性状，调控种子大小也是重要的发育生物学问题，因此，研究种子大小调控机理，具有重要的理论价值和实践意义。但是，目前对植物种子大小调控的分子机制尚不清楚。拟南芥中，UBP14编码去泛素化酶，突变体ubp14种子变大。细胞生物学研究表明，UBP14调节种子大小具有母性效应，并通过促进胚的发育、抑制外珠被细胞分裂调控种子的最终大小，但此过程的分子机制尚不清楚。为了阐明UBP14调控种子大小的遗传和分子机制，本研究运用细胞生物学、生物化学、分子生物学、遗传学等手段，筛选与UBP14相互作用蛋白及其调控的下游因子，解析其生物学功能，揭示UBP14调节种子大小的分子生物学机制，同时挖掘新的种子大小调节基因；分析UBP14与其相互作用因子、其调节因子以及已知种子大小调节因子之间的遗传关系，建立UBP14调节种子大小的遗传通路，扩展种子大小调控的遗传网络，为作物的高产育种提供理论依