大豆生物钟基因ELF4b对生育期的分子调控途径

Growth period is one of the important factors affecting soybean yield. The applicant's previous study found that Gmelf4b knockout mutants had no significant change in flowering time while maturity time was significantly advanced under short-day condition. When planted under long-day condition, the flowering time of Gmelf4b mutant material was significantly earlier , and the normal GmELF4b gene inhibited the flowering of soybean. This indicated that GmELF4b had different regulation mechanisms on soybean growth period traits under different photoperiod conditions. However, the molecular mechanism is still unclear. On the basis of the previous studies on genes in regulation of soybean growth period traits, this project will analyze the inheritance and interaction between GmELF4b gene and other key growth period genes, shuch as J and E1, by observing the phenotype of GmELF4b over-expression and knockout materials in flowering and maturity time. And combining with molecular biological methods such as Y2H and Chip-PCR to screen the proteins interacting with GmELF4b and identify their functions. The molecular regulation pathway of GmELF4b gene on soybean growth period will be revealed. This will help us to understand the cultivate adaptability of soybean, also provide a theoretical basis for soybean breeding.

生育期是影响大豆产量的重要因子之一。申请者前期研究发现，Gmelf4b敲除突变体在短日照条件下种植时开花期没有明显变化，成熟期显著提前；在长日照条件下种植时，Gmelf4b突变体材料开花期显著提前，正常型GmELF4b基因抑制大豆开花。说明GmELF4b在不同光周期条件下对大豆生育期的调控机制不同。但是其具体的调控分子机制尚不十分清楚。在申请者及所在团队前期对生育期基因研究的基础上，本项目通过对GmELF4b过表达和敲除材料开花期与成熟期的表型观察，结合Y2H、ChIP-PCR等分子生物学手段，分析生物钟基因GmELF4b与关键生育期基因J、E1等的遗传及互作关系；筛选与GmELF4b互作的蛋白，鉴定互作蛋白的功能；从而揭示GmELF4b基因对大豆生育期的分子调控途径。为理解大豆的栽培适应性，同时也为大豆产量育种提供理论基础。

生育期是影响大豆产量的重要因子之一。Gmelf4b敲除突变体在短日照条件下种植时开花期没有明显变化，成熟期显著提前；在长日照条件下种植时，Gmelf4b突变体材料开花期显著提前，表现出控制早花早熟的表型。本项目通过对GmELF4b敲除材料开花期与成熟期的表型观察，结合Y2H、ChIP-PCR等分子生物学手段，实验发现GmELF4b与ELF3互作，抑制关键生育期基因E1的转录，GmELF4b蛋白属于DUF1313基因家族，大豆中共有9个DUF1313同源基因由于剂量补偿效应，单突变体Gmelf4b对开花期的影响较小。Gmelf4b突变体能够加快离体叶片的衰老，本研究中PR1病程相关蛋白(pathogenesis-related proteins, PRP或PRs)、TGA (TGACG motif-binding factor)转录因子、查尔酮合成酶 (Chalcone synthase, CHS)等78个基因在突变体的叶片中上调表达。初步揭示了GmELF4b基因调控大豆生育期的分子机制。为理解大豆的栽培适应性，同时也为大豆分子育种提供理论基础。