水稻甜质胚乳突变体m5788的鉴定及基因定位  

Identification and Fine Mapping of Sugary Endosperm Mutant m5788 in Rice(Oryza sativa L.)

作　　者：郑思怡 杨晔 宋远辉[1] 花芹 林泉祥 张海涛[1] 程治军[2] Zheng Siyi;Yang Ye;Song Yuanhui;Hua Qin;Lin Quanxiang;Zhang Haitao;Cheng Zhijun(College of Agriculture,Anhui Agricultural University,Hefei 230036,Anhui,China;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]安徽农业大学农学院,安徽合肥230036 [2]中国农业科学院作物科学研究所,北京100081

出　　处：《作物杂志》2022年第4期14-21,共8页Crops

基　　金：国家自然科学基金(31871603)。

摘　　要：胚乳发育是种子形成的关键,其决定水稻的外观品质和食味品质。m5788是从粳稻品种中花11的组织培养后代中发现的甜质胚乳突变体,其籽粒皱缩,千粒重与穗粒数均显著降低,淀粉合成受阻,可溶性糖含量显著增加。通过对m5788与IRAT129杂交产生的F_(2)代群体分析表明,甜质胚乳性状受1对隐性核基因控制。对569个F_(2)隐性极端单株进行连锁分析和定位,将目的基因定位在8号染色体长臂端Z8-25.8和Z8-25.9之间110kb的区域内。该区间内存在1个与玉米甜质基因Sugary 1氨基酸序列相似性高达82.2%的基因LOC_Os08g40930,编码一个属于淀粉去分支酶(DBE)途径的异淀粉酶ISA1。测序结果表明,该基因序列和启动子在野生型和m5788中不存在碱基差异。qRT-PCR分析结果表明,与野生型相比,突变体中LOC_Os08g40930的表达量明显降低。同时,DBE途径中支链淀粉酶的编码基因表达量也显著降低。因此,m5788携带的isa1基因是一个新发现的等位变异。Starch synthesis in endosperm development determines the appearance and flavor quality of rice grains.m5788 is a shriveled grain sweet embryo mutant derived from the tissue culture progeny of Japonica var.Zhonghua 11.The 1000-grain weight and the number of grains per panicle decreased significantly.Due to the blocking of starch synthesis,the level of soluble sugar increased significantly.Genetic analysis revealed that m5788 was determined by a pair of recessive nuclear genes.Linkage analysis localized the candidate gene to the 110kb region flanked by indel markers of Z8-25.8 and Z8-25.9 on chromosome 8 in 569 F_(2) mutant individuals.In this region there was a putative isoamylase encoding the gene LOC_Os08g40930,which was 82.2%homologous to maize Sugary 1 and was involved in the DBE pathway of the starch debranching enzyme ISA1.The sequencing results showed that no genomic sequence change occurs in LOC_Os08g40930 between wild type and m5788.However,the qRT-PCR analysis showed that the decrease in the expression level of the gene LOC_Os08g40930 in the mutant m5788 was presented together with the expression level of the coding-gene of pullulanase-type in same DBE pathway.All results suggest that isa1 carried by m5788 is a novel allele.

关 键 词：水稻 胚乳发育 精细定位 淀粉合成 

分 类 号：S511[农业科学—作物学]