水稻落粒基因SH8的精细定位与克隆  

Fine mapping and cloning of a seed shattering gene SH8 in rice(Oryza sativa L.)

作　　者：王穆穆 何艳芳 郑永胜[1] 王晖 王丽媛 王东建[1] 张晗[1] 李汝玉[1] WANG Mu-Mu;HE Yan-Fan;ZHENG Yong-Sheng;WANG Hui;WANG Li-Yuan;WANG Dong-Jian;ZHANG Han;LI Ru-Yu(Crop research Institute,Shandong Academy of Agricultural Sciences,Jinan 250100,Shandong,China;Shandong Seed Administration Station,Jinan 250100,Shandong,China)

机构地区：[1]山东省农业科学院作物研究所,山东济南250100 [2]山东省种子管理总站,山东济南250100

出　　处：《作物学报》2022年第8期1948-1956,共9页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31801340)资助。

摘　　要：落粒性是水稻的重要性状之一,是野生稻种子传播和后代繁衍的重要保障,但是容易落粒在栽培稻的生产中会造成产量损失。目前,在水稻中已经克隆了一些落粒相关基因,但是这些基因并不能解释水稻落粒的全部表型变异。本研究从白谷(Pei-kuh)和普通野生稻(W1944)构建的重组自交系中选取落粒性强且不含有SH4基因的材料E6-5,与Pei-kuh进行杂交构建分离群体,将以前检测到位于8号染色体的落粒QTL精细定位于26.4 kb的区间内,并把该位点的落粒基因命名为SHATTERING8(SH8)。该区段共有4个编码基因,Pei-kuh和E6-5的测序比对发现LOC_Os08g41950基因在编码区有3个碱基的差异,同时实时定量PCR分析表明该基因在离层部位表达,因此我们把LOC_Os08g41950作为SH8的目标候选基因。为了验证LOC_Os08g41950是否参与水稻落粒的调控,我们利用来自E6-5的LOC_Os08g41950编码序列构建了过表达载体并遗传转化Pei-huh。落粒表型鉴定结果表明,与Pei-huh相比,转基因植株的落粒性明显增强,不仅种子脱落所需的拉力值显著降低,而且还具有更光滑的离层断裂面。本研究有助于促进水稻驯化和水稻落粒调控机制的研究。Seed shattering is an important trait for seed dispersal and reproduction of offspring in wild rice.It is a vital guarantee for seed dispersal and offspring reproduction of wild rice,but easy grain dropping will cause yield loss in domesticated rice production.Although some genes related to seed shattering have been cloned in rice,these genes were not responsible for all phenotype variation of rice seed shattering.In this study,a recombinant inbred line(E6-5)was selected from a cross between an indica variety Pei-kuh and an Asian common wild rice W1944 and hybridized with Pei-kuh to construct the isolated population.E6-5harbored W1944 introgression segment on chromosome 8,but it had not carried SH4 gene and exhibited a very easy seed shattering phenotype.By analyzing an F2 segregation population constructed using E6-5 and Pei-kuh,we narrowed down the SHATTERING8(SH8,q SHT-8)in the 26.4 kb interval.There were four protein-coding genes in this region.The comparison of PEI-Kuh and E6-5 sequencing revealed that LOC_Os08g41950 contained three single nucleotide polymorphisms(SNPs)in coding region.Meanwhile,qRT-PCR revealed that LOC_Os08g41950 was expressed in the junction of flower and pedicel,where the abscission layer was formed and shed off.We considered LOC_Os08g41950 as the candidate gene for SH8.To verify whether LOC_Os08g41950 was responsible for rice seed shattering,we constructed an overexpression vector using LOC_Os08g41950encoding sequence from E6-5 and transformed it into Pei-huh.Compared with Pei-kuh,the shattering ability of transgenic plants was significantly enhanced.In addition,consistent with the BTS testing results,transgenic plants had smoother fracture surface of pedicel compared with that of Pei-kuh in scanning electron microscopy photos.These results would facilitate the study of rice domestication and seed shattering regulation mechanism.

关 键 词：普通野生稻 落粒性 离层 基因克隆 SH8基因 

分 类 号：S511[农业科学—作物学]