The simultaneous improvement of grain quality and yield of cereal crops is a major challenge for modern agriculture. Here we show that a rice grain yield quantitative trait locus qLGY3 encodes a MADS-domain transcription factor OsMADS1, which acts as a key downstream effector of G-protein βγ dimers. The presence of an alternatively spliced protein OsMADS1lgy3 is shown to be associated with formation of long and slender grains, resulting in increases in both grain quality and yield potential of rice. The Gγ subunits GS3 and DEP1 interact directly with the conserved keratin-like domain of MADS transcription factors, function as cofactors to enhance OsMADS1 transcriptional activity and promote the co-operative transactivation of common target genes, thereby regulating grain size and shape. We also demonstrate that combining OsMADS1lgy3 allele with high-yield-associated dep1-1 and gs3 alleles represents an effective strategy for simultaneously improving both the productivity and end-use quality of rice.
同時(shí)提高谷類作物的籽粒品質(zhì)和產(chǎn)量是現(xiàn)代農(nóng)業(yè)面臨的主要挑戰(zhàn)。本文我們發(fā)現(xiàn)水稻籽粒產(chǎn)量數(shù)量性狀基因座qLGY3，它編碼一個(gè)含有MADS域的轉(zhuǎn)錄因子OsMADS1，是G蛋白βγ二聚體下游的關(guān)鍵效應(yīng)子?？勺兗艚拥鞍譕sMADS1lgy3會(huì)產(chǎn)生細(xì)長(zhǎng)粒，提高稻谷的品質(zhì)和產(chǎn)量。Gγ亞基GS3和DEP1與MADS轉(zhuǎn)錄因子保守的角蛋白樣結(jié)構(gòu)域直接相互作用，作為輔助因子發(fā)揮作用，增強(qiáng)OsMADS1的轉(zhuǎn)錄活性，協(xié)同反式激活共同的靶基因，繼而調(diào)控籽粒大小和形狀。我們還證明，將OsMADS1lgy3等位基因與高產(chǎn)量相關(guān)的等位基因dep1-1和gs3聚合，可以同時(shí)提高水稻的產(chǎn)量和稻米品質(zhì)。