摘要
Improving protein quality and grain yield traits coordinately is an important goal for crop breeding.To date,many protein-quality or grain-yield regulation genes have been identified.However,the genetic strategies integrating these genes in good-protein-quality and high-yield crop breeding practice are far from established.Here,we characterized the functions of the MADS domain-containing protein Zm MADS8 and Zea mays G protein gamma subunit 1(Zm GG1)in regulating protein quality and grain yield of maize.Zm MADS8 positively regulates zein protein accumulation and negatively regulates nonzein protein and lysine levels in kernels by interacting with Zm MADS47 to promote the transcriptional activation of Opaque2.Additionally,Zm MADS8 regulates starch content of kernels by targeting genes involved in starch biosynthesis.Zm GG1,a putative interactor of Zm MADS8,negatively regulates kernel number with a trade-off effect on kernel starch accumulation.The mads8;zmgg1 double mutant improved protein quality by attenuating zein biosynthesis and increasing essential lysine level,and increased grain yield by increasing kernel number,compensating for decreased starch biosynthesis.Our findings revealed the biological function of Zm MADS8 and Zm GG1 in regulating protein quality and yield related traits and suggested a genetic strategy by direct editing of Zm MADS8 and Zm GG1 to improve grain yield and protein quality simultaneously.
基金
supported by the Biological Breeding-National Science and Technology Major Project(2023ZD0406804,2023ZD0402701)
Major Project of Hubei Hongshan Laboratory(2022hszd019)
First-Class Discipline Construction Funds of the College of Plant Science and Technology at Huazhong Agricultural University(2022ZK PY002)。
