水稻SL基因调控水稻的粒形

Regulation of Grain Size by SL Gene in Rice

水稻产量和稻米品质的提高是水稻研究的中心问题。水稻产量主要取决于单株穗数、每穗粒数和粒重;粒重作为一个非常重要的产量性状,由粒长、粒宽和粒厚所决定。影响粒重和粒形的基因多为数量性状基因,精细定位并克隆到的较少。本研究中,我们克隆到一个影响粒形的基因SL,超表达(SL-OE)转基因植株表现出粒长增加、粒宽减小、叶宽减小的表型;同时,SL-RNAi的转基因植株呈现出粒长缩短、叶宽增加的表型。颖壳表面细胞在超表达转基因植株中伸长,而在RNAi转基因植株中缩短。叶片横向细胞数目在转基因植株中发生变化,推测SL基因可能与细胞分裂相关。SL-OE转基因植株中GW2基因被明显上调,说明SL基因可能通过调节GW2的表达对水稻粒宽造成影响。另外,SL基因影响稻米的品质。

Yield and quality of the grain are two major issues in rice （Oryza sativa）. Panicle number per plant, grain number per panicle, and grain weight are three important components of yield. Grain weight is specified by seed length, width and thickness. Most genes accounting for grain weight and size are quantitative trait loci （QTLs）, but only a few of them have been fine-mapped and cloned. Here, we reported the functional characterization of a SL gene, which showed obviously increased grain length, deceased grain width and leaf width when over expressed. And SL-RNAi transgenic plants showed decreased grain length and increased leaf width etc. The cells in the glume surface were stretched in SL over-expression （SL-OE） plants and shortened in SL RNA-interference （SL-RNAi） plants. Cell numbers in the leaf changed latitudinally in the transgenic plants, indicating SL gene might regulate cell division. GW2 gene was up-regulated in SL-OE plants, and genes influencing grain width might take part in the SL gene pathway. And SL gene showed some influence on rice quality.