), 李珅, 王东梅, 沙小茜, 何冠华, 张登峰, 李永祥, 刘旭洋, 王天宇, 黎裕, 李春辉()
), LI Shen, WANG Dong-Mei, SHA Xiao-Qian, HE Guan-Hua, ZHANG Deng-Feng, LI Yong-Xiang, LIU Xu-Yang, WANG Tian-Yu, LI Yu, LI Chun-Hui()
干旱是影响玉米生产的主要非生物胁迫之一。为了挖掘玉米优异抗旱基因, 本研究基于墨西哥大刍草和玉米自交系PH4CV构建的BC2F6群体, 通过苗期抗旱性初步鉴定, 筛选出抗旱性强的渗入系TP180。干旱胁迫后发现渗入系TP180较轮回亲本PH4CV萎蔫程度更小, 并且复水后存活率显著高于PH4CV。全基因组基因型鉴定发现, 渗入系TP180含有0.6%的墨西哥大刍草导入。通过开展TP180和PH4CV不同水分条件下的转录组测序, 在渗入系TP180和PH4CV之间共鉴定了 2307个差异表达基因, 不同胁迫重叠差异表达基因共122个, 这些基因涉及生长素途径, 茉莉酸途径等, 包含多个转录因子。整合差异表达基因和含大刍草导入区段分析, 鉴定出2个抗旱候选基因Zm00001d033050和Zm00001d002025, 并进一步开展了RT-PCR分析。本研究为挖掘大刍草中抗旱基因资源提供了重要材料和信息基础。
Drought is one of the major abiotic stresses affecting maize production. In order to explore new genes for drought tolerance in maize, the BC2F6 population constructed on the basis of teosinte and PH4CV was screened for the drought-tolerant introgression lines TP180 through the preliminary identification of drought tolerance at seedling stage. After drought stress, the TP180 was less wilting than its recurrent parent PH4CV, and the survival rate of TP180 was significantly higher than PH4CV after rehydration. Genome-wide genotypic identification revealed that introgression line TP180 contained 0.6% of the teosinte genome. By transcriptomic analysis of TP180 and PH4CV under different water conditions, a total of 2307 differentially expressed genes were identified between TP180 and PH4CV, and 122 of the differentially expressed genes were identified under both two drought stresses conditions. These genes were related to the growth hormone pathway, jasmonic acid pathway, etc., and contained multiple transcription factors. Integrating the differentially expressed genes and the analysis of introgression region containing the teosinte genome, two drought-resistant candidate genes (Zm00001d033050 and Zm00001d002025) were identified and further validated by RT-PCR. This study provides an important germplasm and information for mining drought-resistant gene of the teosinte.