HPY1协同促进水稻源库平衡提高产量水平

Gain-of-function allele of HPY1 coordinates source and sink to increase grain yield in rice

水稻产量在生理上是由光合作用能力(源)和籽粒大小/数量(库)共同决定的.同时提升源和库将有助于水稻产量的进一步提升.因此,发掘协同促进源库的有利基因将有助于在分子水平上解析水稻源库相互协调的作用机制,从而促进水稻高产改良.本研究发现HPY1是一个由转座子衍生而来的转录因子编码基因,其高度保守,在水稻种质资源中均无任何突变.本文通过辐射诱变得到了1个HPY1的功能获得型突变等位基因,其通过协同促进Rubisco活性和籽粒大小从而提高水稻产量.HPY1通过直接结合Rubisco小亚基编码基因RbcS2、RbcS3和RbcS4,以及调控籽粒大小基因CCP1、FLO2,上调其转录,从而提高水稻光合速率、生物量、种子大小和籽粒产量.该发现不仅有助于从分子水平深入理解水稻源库协调的作用机制,同时也提供了一种水稻高产改良的有效策略.

Rice,as a major food crop,is facing the critical challenge of sustaining increase in yield potential to feed the burgeoning population[1].During the last decades,the discovery of dwarf rice has contributed to a doubling rice grain yield due to its high nitrogen tolerance and increased harvest index[2,3].However,the excessive input of nitrogen in rice cultivation has led to severe environmental pollution worldwide,posing a threat to sustainable human development[4].Consequently,the enhancement of photosynthetic rate emerges as the focus point of sustainable green development for rice in the future,as it serves as the cornerstone of crop plant production and accounts for over 90%of plant biomass[5].Generally,highly productive rice varieties are typically characterized by a robust source,displaying high nitrogen utilization and/or photosynthetic efficiency,along with a large sink,characterized by an increased grain number and/or high grain weight.When the source and sink function synergistically,appropriate augmentation of the sink can improve photosynthetic efficiency,leading to higher yields.Despite its intriguing nature,this phenomenon remains poorly understood[6].Presently,over one hundred genes related to grain number and grain weight had been cloned in rice,but fewer cases are correlated with the interaction between the source and the sink of rice[7].Therefore,exploration of new genetic resources capable of coordinate the source and sink holds tremendous significance.