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

作　　者：韩洁楠 张泽 刘晓丽 李冉 上官小川 周婷芳 潘越 郝转芳[1] 翁建峰[1] 雍洪军[1] 周志强[1] 徐晶宇[2] 李新海[1,2] 李明顺 HAN Jie-Nan;ZHANG Ze;LIU Xiao-Li;LI Ran;SHANG-GUAN Xiao-Chuan;ZHOU Ting-Fang;PAN Yue;HAO Zhuan-Fang;WENG Jian-Feng;YONG Hong-Jun;ZHOU Zhi-Qiang;XU Jing-Yu;LI Xin-Hai;LI Ming-Shun(Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China;College of Agriculture,Heilongjiang Bayi Agricultural University,Daqing 163319,Heilongjiang,China)

机构地区：[1]中国农业科学院作物科学研究所,北京100081 [2]黑龙江八一农垦大学农学院,黑龙江大庆163319

出　　处：《作物学报》2024年第5期1207-1222,共16页Acta Agronomica Sinica

基　　金：国家重点研发计划项目(2021YFD1201004);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。

摘　　要：糯玉米是主要鲜食玉米类型,opaque2(o2)基因导入可增加籽粒赖氨酸含量,但同时引起籽粒皱缩、淀粉含量下降等,限制了其育种应用。为发掘优良糯玉米受体,以籽粒饱满圆型o2近等基因系(o2-NIL)糯2/wx1wx1o2o2和皱缩型黄糯2/wx1wx1o2o2为研究材料,通过对鲜食期、成熟期的百粒重和籽粒成分测定,发现淀粉和可溶性糖含量不同可能是导致2份糯玉米o2-NILs表型差异的主要原因。利用实时荧光定量PCR技术分析,发现授粉后10~24 d两糯玉米o2-NILs中6个淀粉合成基因动态表达模式不同,其中Sh1、Sh2、SSIIIa和SBEIIb差异较大。分析胚乳转录组数据,发现两糯玉米o2-NILs中24个海藻糖和糖基水解酶编码基因和48个o2胚乳修饰基因变化不同,以上结果表明淀粉合成关键基因前期表达量高,后期与对照无差异,且糖代谢基因表达变化有利于淀粉合成可能是糯2/wx1wx1o2o2淀粉含量和百粒重不受o2突变影响,籽粒性状明显优于黄糯2/wx1wx1o2o2的重要原因,同时多个胚乳修饰基因的差异表达可能与该结果直接相关。本研究结果可为o2突变体在玉米育种中的应用提供重要参考。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,Huangnuo2/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 revealed 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 significantly 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 st

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 

分 类 号：S513[农业科学—作物学]