Identification of Putative Candidate Genes for Water Stress Tolerance in Canola (Brassica napus).
Identification of Putative Candidate Genes for Water Stress Tolerance in Canola (Brassica napus).
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双低油菜籽（甘蓝型油菜）耐水胁迫的假定候选基因的鉴定
DOI：
10.3389/fpls.2015.01058
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发表时间：
2015
影响因子：
5.6
通讯作者：
Yan G
中科院分区：
文献类型：
--
作者：
Zhang J;Mason AS;Wu J;Liu S;Zhang X;Luo T;Redden R;Batley J;Hu L;Yan G
干旱胁迫直接抑制甘蓝型油菜(Brassica Napus)的成苗，导致植株密度降低，产量下降。为了分析这一复杂的性状，在水培系统中，用聚乙二醇6000(−0.5 Mpa，S5)模拟水分胁迫条件和正常条件(0.0Mpa，S0)，对140份甘蓝型油菜材料进行了表型鉴定。表型变异和遗传力表明，根冠比是耐水分胁迫的可靠指标。在此基础上，利用25495个单核苷酸多态性(SNPs)对66份材料(16份耐水分胁迫品系、34份中等品系和16份敏感品系)进行了基因分型。全基因组关联研究发现了16个与水分胁迫反应显著相关的基因座。利用两份甘蓝型油菜材料进行了RNA测序，检测了正常和水分胁迫条件下的差异表达基因。通过将RNA测序检测到的差异表达基因与来自GWAs的显著关联基因相结合，共鉴定出79个候选基因，其中8个基于拟南芥基因本体论推测与耐旱性相关。这些基因的功能验证可能会为甘蓝型油菜的选择和育种确定关键的干旱相关基因。我们的研究结果为油菜耐水分胁迫的遗传基础研究提供了新的思路。
Drought stress can directly inhibit seedling establishment in canola (Brassica napus), resulting in lower plant densities and reduced yields. To dissect this complex trait, 140 B. napus accessions were phenotyped under normal (0.0 MPa, S0) and water-stressed conditions simulated by polyethylene glycol (PEG) 6000 (−0.5 MPa, S5) in a hydroponic system. Phenotypic variation and heritability indicated that the root to shoot length ratio was a reliable indicator for water stress tolerance. Thereafter, 66 accessions (16 water stress tolerant, 34 moderate and 16 sensitive lines) were genotyped using 25,495 Brassica single nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) identified 16 loci significantly associated with water stress response. Two B. napus accessions were used for RNA sequencing, with differentially-expressed genes under normal and water-stressed conditions examined. By combining differentially-expressed genes detected by RNA sequencing with significantly associated loci from GWAS, 79 candidate genes were identified, of which eight were putatively associated with drought tolerance based on gene ontology of Arabidopsis. Functional validation of these genes may confirm key drought-related genes for selection and breeding in B. napus. Our results provide insight into the genetic basis of water stress tolerance in canola.