苦荞lazy1突变体匍匐形成的调控机制与关键基因功能分析

重力是参与植株形态建成以及生长和发育的重要环境因子，研究植物对重力的反应及其调控机理对于作物株型改良以及产量提高具有重要指导意义。苦荞是特色杂粮作物，营养与保健功能突出，但产量水平较低。项目组通过60Co-γ辐射诱变获得了一个地上部分负向地性生长缺陷的突变体LW600-47-1(暂命名为lazy1)。lazy1呈匍匐状生长，表型稳定遗传且不能被外源激素恢复。lazy1分枝与主茎的角度明显增加，茎节数和分枝数显著提高，单株产量较野生型提高17.48%。对比转录组测序发现lazy1茎发生弯曲的过程中存在大量的差异表达基因。本项目拟在此基础上深入开展lazy1的组织细胞特征，生长素与赤霉素水平与分布规律，重力性反应特征，关键基因挖掘、鉴定、克隆、表达与功能分析等相关研究，为解析苦荞lazy1匍匐生长的生理与分子调控机制提供理论依据，同时为苦荞株型以及分枝角度的遗传改良提供科学参考。

Gravity is an important environmental factor that involves in plant morphogenesis, growth and development. It is crucial to verify the regulation mechanism of plant gravity response for the improvement of crop type and yield. Tartary buckwheat is a special coarse cereal that owns prominent nutritional and healthy functions, but exhibits low yield character. Our team obtained a mutant line LW600-47-1 (temporarily named as lazy1) that showed defection of negative gravitropism. lazy1 exhibited hereditary stability of creeping growth phenotype that could not be recovered by exogenous hormones. In addition, lazy1 showed significantly increased branching angle, stem node number and branch number, of which yield per plant was 17.48% higher than wildtype(WT). A large number of differential expressed genes had been identified during the process of stem bending between lazy1 and WT by comparative transcriptome sequencing. In this project, the characteristics of tissues and cells, the levels and distribution of auxin and gibberellin, the response of gravity of lazy1 will be investigated, and the key genes involving in creeping growth will be identified, cloned and verified based on the previous results. The present work will provide the theoretical foundation for illuminating the physiological and molecular regulatory mechanism of creeping growth of lazy1. And the expecting results will provide scientific reference for genetic improvement of plant type and branching angle for Tartary buckwheat.