1.Food Crops Institute, Hubei Academy of Agricultural Science;2.Institute of Crop Science, Chinese Academy of Agricultural Science;3.Xianning Academy of Agricultural Sciences
Youth Science Foundation of Hubei Academy of Agricultural Sciences (2020NKYJJ02); Key Research and Development Project of Hubei Province (2021BBA225); Hubei Agricultural Science and Technology Innovation Center, Major Science and Technology Research and Development Project (2020-620-000-002-01)
叶片颜色通常与叶绿体数量、结构、光合能力等相关，以C4模式植物谷子的叶色突变体为材料，克隆突变基因并研究其功能，对于解析C4植物叶绿体发生发育及光合作用调控机制具有重要作用。本研究从谷子品种豫谷1号EMS突变体库中分离鉴定到一个条纹叶突变体t122。该突变体生长发育迟缓，且叶片呈现不规则白色条纹。农艺性状测定结果显示，t122的株高、叶长、叶宽、主穗粗、主穗重、结实率等性状均显著降低，而单株穗数相比野生型显著增加，同时光合性能受到影响。叶片解剖结构观察发现t122维管束间距离、维管束间细胞层数、叶片横截细胞面积均无明显改变，而叶片细胞长度显著增加。叶绿体超微结构观察表明t122一部分叶片细胞叶绿体缺失，而另一部分叶片细胞含有发育正常的叶绿体。遗传分析结果显示，t122突变表型由一对隐性核基因控制。利用MutMap法，将候选基因初步定位于3号染色体24.0 Mb～30.0 Mb区间内，研究的结果为谷子条纹叶基因的克隆及功能研究奠定了基础。
Leaf color is usually determined by the number, structure, and photosynthetic characters of the chloroplast. Isolation of the functional genes in leaf discoloration mutants of the C4 model plant foxtail millet and deciphering their functions is a way to disclose the regulation mechanism of C4 plant chloroplast biogenesis, development and photosynthesis. In this study, a stripe-leaf mutant t122 was identified from the EMS-induced mutant library of the foxtail millet variety Yugu1. The mutant t122 was observed with developmental retardation, and irregular white stripes on leaves. In contrast to the wild type, the significant decrease on the plant height, leaf length, leaf width, main panicle diameter, main panicle weight, and seed setting rate was observed in t122 mutant, whereas an increase on the panicle number per plant was detected. The photosynthetic capacity of t122 was impaired. By the leaf anatomy analysis, no significant difference in the distance between leaf veins, the number of cell layers between vascular bundles, and the cross-sectional cell area of leaves was observed in t122; however, an increased on the leaf cell length was detected. The ultrastructural observation of chloroplasts showed that, in t122 the chloroplasts showing functional structure were only detected in subsets of leaf cells. The segregation analysis suggested that the stripe-leaf trait of t122 was controlled by a single recessive nuclei-encoding gene. Using the method of MutMap, the candidate gene was mapped to the region of 24.0 Mb - 30.0 Mb on chromosome 3. Collectively, these results laid a good foundation for future cloning and functional characterization of the stripe-leaf gene in foxtail millet.
张 硕,智 慧,张 伟,等.谷子条纹叶突变体t122表型分析及基因初定位[J].植物遗传资源学报,2022,23(4):1076-1084.复制