Plant Genomics Laboratory, Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon, Republic of Korea.
Agriculture and Life Sciences Research Institute, Kangwon National University, Chuncheon, Republic of Korea.
Physiol Plant. 2022 May;174(3):e13718. doi: 10.1111/ppl.13718.
Drought stress is a major abiotic stress that limits rice yield. Therefore, the development of new varieties tolerant to drought stress is a high priority in breeding programs. In this study, 150 rice M mutant lines, previously developed using gamma-ray irradiation, were used, and a drought-insensitive rice mutant (ditl1) was selected by drought stress screening. The ditl1 mutant exhibited significantly decreased water loss, leaf curling, and H O accumulation under drought stress. Chlorophyll leaching assay and toluidine blue staining suggested lower cuticle permeability in ditl1 mutants than in wild-type (WT) plants. In addition, transmission electron microscopy revealed that ditl1 plants accumulated more cuticular wax on the epidermal surface. Whole-genome resequencing analysis suggested that the deletion of a single nucleotide on the LOC_Os05g48260 gene, a putative ortholog of WSD1 (wax ester synthase/diacylglycerol O-acyltransferase in Arabidopsis), maybe be the gene responsible for the drought insensitive phenotype of ditl1. The ditl1 mutant will be a valuable breeding resource for developing drought stress tolerant rice cultivar.
干旱胁迫是限制水稻产量的主要非生物胁迫因素。因此，培育耐旱品种是育种计划的重中之重。本研究利用γ射线辐照诱变技术创制了 150 份水稻 M 突变体，通过干旱胁迫筛选获得了一个耐旱突变体（ditl1）。与野生型（WT）相比，ditl1 突变体在干旱胁迫下的水分损失、叶片卷曲和 H2O2积累显著减少。叶绿素浸出实验和甲苯胺蓝染色表明，ditl1 突变体的角质层通透性低于 WT 植株。此外，透射电子显微镜显示，ditl1 植株在表皮表面积累了更多的角质层蜡。全基因组重测序分析表明，LOC_Os05g48260 基因（拟南芥的蜡酯合酶/二酰基甘油 O-酰基转移酶的同源物）上单个核苷酸的缺失可能是 ditl1 突变体耐旱表型的原因。ditl1 突变体将成为培育耐旱水稻品种的宝贵资源。
