作物学报2024，Vol.50Issue(5)：1207-1222,16.DOI:10.3724/SP.J.1006.2024.33046
o2突变引起糯玉米籽粒淀粉积累差异研究
Analysis of differential accumulation of starch in waxy maize grain caused by the o2 mutation gene
摘要
Abstract
The primary variety of fresh maize known as waxy maize undergoes a transformation with the introduction of the opaque2(o2)mutant gene,resulting in an increased lysine content,thus improving the grain's nutritional composition.Yet,the o2 mutation brings about desirable agronomic traits such as wrinkle formation and a decrease in starch content,which restrict its use in breeding applications.To explore the high performing waxy maize o2 receptors,we capitalized on the use of o2 near-isogenic line(o2-NIL),specifically the plump and round grain type Nuo 2/wx1wx1o2o2 and its wrinkled counterpart,Huang-nuo2/wx1wx1o2o2.Measurements of 100-grain weight and grain composition at the fresh ear and mature stages showed that there was difference in starch and soluble sugar content,which might be the primary cause of kernel phenotype variation between the two waxy maize o2-NILs.Genetic analysis of starch synthesis in the two o2-NILs was performed using qRT-PCR technique re-vealed that six gene-regulated trends fluctuated between 10 and 24 days after pollination,among which Sh1,Sh2,SSⅢa,and SBEⅡb genes were significant differences.Endosperm transcriptomes indicated that 24 genes encoding trehalose and glycosyl hydrolases and 48 genes involved in endosperm modification exhibited distinct changes between the two o2-NILs.There was no detectable alteration in the 100-grain weight or the starch content of Nuo 2/wx1wx1o2o2,which may well be tied to the early high-level expression of the primary starch synthesis gene,leaving later stages unchanged compared with the control.Furthermore,the shifts in the expression of sugar metabolism genes was beneficial to starch synthesis,which may be an important reason why starch content and 100-kernel weight of Nuo 2/wx1wx1o2o2 were unaffected by the o2 mutation,and grain traits were signifi-cantly better than the superior grain traits compared with Huangnuo 2/wx1wx1o2o2.These results may be directly related to the differential expression of multiple endosperm modifying genes.The results of this study can provide important reference for the future utilization of o2 mutants in maize breeding.关键词
糯玉米/糯2/wx1wx1o2o2/黄糯2/wx1wx1o2o2/籽粒饱满度/淀粉/糖代谢/差异基因Key words
waxy maize/Nuo 2/wx1wx1o2o2/Huangnuo 2/wx1wx1o2o2/kernel fullness degree/starch/sucrose metabolism/different expression genes引用本文复制引用
韩洁楠,雍洪军,周志强,徐晶宇,李新海,李明顺,张泽,刘晓丽,李冉,上官小川,周婷芳,潘越,郝转芳,翁建峰..o2突变引起糯玉米籽粒淀粉积累差异研究[J].作物学报,2024,50(5):1207-1222,16.基金项目
本研究由国家重点研发计划项目(2021YFD1201004)和财政部和农业农村部国家现代农业产业技术体系建设专项(玉米,CARS-02)资助.This study was supported by the National Key Research and Development Program of China(2021YFD1201004)and the China Agriculture Research System of MOF and MARA(Maize,CARS-02). （2021YFD1201004）
