Loci, genes, and mechanisms associated with tolerance to ferrous iron toxicity in rice (Oryza sativa L.)
Loci, genes, and mechanisms associated with tolerance to ferrous iron toxicity in rice (Oryza sativa L.)
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DOI：
10.1007/s00122-015-2569-y
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发表时间：
2015-10-01
影响因子：
5.4
通讯作者：
Frei, Michael
中科院分区：
文献类型：
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作者：
Matthus, Elsa;Wu, Lin-Bo;Frei, Michael
水稻全基因组关联研究获得了与铁毒耐性相关的位点和候选基因，揭示了与铁毒耐性相关的生化机制。因此，了解与铁毒性耐受性相关的遗传和生理机制对于适应性育种和生物强化至关重要。我们进行了全基因组关联研究（GWAS），暴露人口的329加入代表所有亚组的水稻亚铁胁迫（1000 ppm，5天）。候选基因的表达模式和序列多态性进行了调查，和生理假设相关的候选位点进行了测试，使用一个子集的对比单倍型。铁包括和不包括宽容的基因型进行了观察，并拍摄铁浓度解释约15.5%的变化，在叶片症状的形成。对7个性状的GWAS共检测到20个SNP标记，超过了-log（10）P > 4.0的显著性阈值，代表了18个不同的位点。一个位点映射为叶面症状形成的1号染色体上含有两个假定的谷胱甘肽-S-转移酶，强烈表达铁胁迫下，并显示序列多态性与最显着的SNP完全连锁不平衡。对比该位点的单倍型显示脱氢抗坏血酸还原酶活性的显著差异，这影响了植物在铁胁迫下的氧化还原状态。我们的结论是，在铁胁迫下保持叶片氧化还原稳态代表了一个重要的耐受机制与通过GWAS确定的一个位点。
A genome-wide association study in rice yielded loci and candidate genes associated with tolerance to iron toxicity, and revealed biochemical mechanisms associated with tolerance in contrasting haplotypes.Iron toxicity is a major nutrient disorder affecting rice. Therefore, understanding the genetic and physiological mechanisms associated with iron toxicity tolerance is crucial in adaptive breeding and biofortification. We conducted a genome-wide association study (GWAS) by exposing a population of 329 accessions representing all subgroups of rice to ferrous iron stress (1000 ppm, 5 days). Expression patterns and sequence polymorphisms of candidate genes were investigated, and physiological hypotheses related to candidate loci were tested using a subset of contrasting haplotypes. Both iron including and excluding tolerant genotypes were observed, and shoot iron concentrations explained around 15.5 % of the variation in foliar symptom formation. GWAS for seven traits yielded 20 SNP markers exceeding a significance threshold of -log(10) P > 4.0, which represented 18 distinct loci. One locus mapped for foliar symptom formation on chromosome 1 contained two putative glutathione-S-transferases, which were strongly expressed under iron stress and showed sequence polymorphisms in complete linkage disequilibrium with the most significant SNP. Contrasting haplotypes for this locus showed significant differences in dehydroascorbate reductase activity, which affected the plants' redox status under iron stress. We conclude that maintaining foliar redox homeostasis under iron stress represented an important tolerance mechanism associated with a locus identified through GWAS.