玉米叶色突变体遗传分析及基因定位

Fine Mapping and Candidate Gene Analysis of Leaf Color Mutant in Maize

玉米叶色与叶绿体及结构相关,调控光合产量,因而对调控叶色基因的遗传研究或克隆将有助于玉米光合产量的遗传改良和植物光合作用理论机制的解析。本研究以玉米W22::Mu介导的综31为遗传背景的导入系群体为材料,获得了细胞核单隐性基因控制、叶绿体结构和数目异常、色素缺失和PSII显著降低的叶色突变体。使用覆盖B73基因组的SSR标记将突变位点定位于约2. 95 Mb区间(bnlg1863~umc2075)。基于区段标记开发和1200单株分离群体将突变位点精细定位于约900 kb区间(B73 Ref Gen_V4; S1~S7区间),经区段内基因表达和功能分析获得了候选基因Zm00001d010000,该基因编码硫氧还蛋白,与突变体表型形成相关。该研究将为光合产量的遗传改良和植物光合作用理论机制解析提供重要的基因或标记资源。

The leaf color of maize is associated to the content and structure of chloroplast, which is the com- partment and of importance in photosynthesis. Genetic analysis and isolation of genes that control the leaf color will provide insights in the genetic improvement for photosynthetic yield and exploration of the theoretical mechanism. In this study, by screening for maize mutants generated by W22： ：Mu in introgression lines with genetic back- ground of Z31 , we obtained a leaf color mutant with the abnormal chloroplast, lack of pigment and the reduction of PSII, which was controlled by a single recessive locus. By the low-resolution genetic mapping using the SSR mark- ers, this mutation locus was mapped to a 2.95 Mb interval（ B73 RefGen_V4 ;bnlg1863-ume2075 ）. Furthermore, this locus was finely mapped to a - 900 kb interval（ B73 RefGen_V4 ; S1-S7 ） by 1200 individuals plants from BC6F2 and developed SSR. Taking advantage of gene annotation and expression analysis,we identified a strong candidate gene Zm00001d010000 that encodes for thioredoxin. Thus, the study could provide genetic material and the selection markers that become valuable in theoretical and applied research for increasing photosynthetic yield.