Lu Guangyuan, Tian Zhitao, Chen Peiyuan, Liang Zhiling, Zeng Xinyu, Zhao Yongguo, Li Chunsheng, Yan Tao, Hang Qian, Jiang Lixi
School of Biology and Food Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Plants (Basel). 2024 Nov 23;13(23):3296. doi: 10.3390/plants13233296.
Drought constitutes a noteworthy abiotic stressor, detrimentally impacting seed germination, plant development, and agricultural yield. In response to the threats imposed by climate change and water paucity, this study examined the morphological divergence and genetic governance of drought resilience traits at the germination stage in 196 rapeseed ( L.) lines under both normal (0 MPa) and drought-induced stress (-0.8 MPa) scenarios. Our study showed that the composite drought tolerance D value is a reliable index for identifying drought resilience. Through a genome-wide association study (GWAS), we uncovered 37 significant SNP loci and 136 putative genes linked to drought tolerance based on the D value. A key discovery included the gene BnaA01g29390D (), encoding 9-cis-epoxycarotenoid dioxygenase, which exhibited significantly heightened expression levels in drought-resistant accessions ( < 0.01), underscoring its potential as a positive drought stress regulator and a suitable candidate for genetically enhancing drought resilience. Moreover, we pinpointed four stress-reactive transcription factors (BnaA07g26740D, BnaA07g26870D, BnaA07g26910D, and BnaA07g26980D), two E3 ubiquitin-protein ligases (BnaA05g22900D and BnaC06g28950D), two enzymes (BnaA01g29390D and BnaA03g48550D), and two photosystem-associated proteins (BnaA05g22950D and BnaC06g28840D) as vital components in drought response mechanisms. The construction of a regulatory network reveals an ABA-dependent pathway () that contributes to drought tolerance in rapeseed seedlings, alongside the involvement of a drought avoidance strategy (). The SNPs and genes unveiled in this study offer a substantial theoretical foundation for subsequent investigations targeting genetic improvement for drought resilience during seed germination in rapeseed.
干旱是一种值得关注的非生物胁迫因素，对种子萌发、植物发育和农业产量产生不利影响。为应对气候变化和水资源短缺带来的威胁，本研究考察了196个油菜（L.）品系在正常（0 MPa）和干旱诱导胁迫（-0.8 MPa）条件下萌发阶段抗旱性状的形态差异和遗传调控。我们的研究表明，综合耐旱性D值是鉴定抗旱性的可靠指标。通过全基因组关联研究（GWAS），我们基于D值发现了37个与耐旱性相关的显著SNP位点和136个推定基因。一项关键发现是基因BnaA01g29390D（），其编码9-顺式环氧类胡萝卜素双加氧酶，在抗旱材料中表达水平显著升高（<0.01），凸显了其作为干旱胁迫正向调节因子的潜力以及作为遗传增强抗旱性的合适候选基因。此外，我们确定了四个胁迫反应转录因子（BnaA07g26740D、BnaA07g26870D、BnaA07g26910D和BnaA07g26980D）、两个E3泛素蛋白连接酶（BnaA05g22900D和BnaC06g28950D）、两种酶（BnaA01g29390D和BnaA03g48550D）以及两种光系统相关蛋白（BnaA05g22950D和BnaC06g28840D）是干旱响应机制的重要组成部分。调控网络的构建揭示了一条有助于油菜幼苗耐旱性的ABA依赖途径（），以及一种避旱策略的参与（）。本研究中发现的SNP位点和基因，为后续针对油菜种子萌发期抗旱性遗传改良的研究提供了坚实的理论基础。
