Fine mapping of the qHTB1-1QTL, which confers heat tolerance at the booting stage, using an Oryza rufipogon Griff. introgression line
Fine mapping of the qHTB1-1QTL, which confers heat tolerance at the booting stage, using an Oryza rufipogon Griff. introgression line
复制标题
使用 Oryza rufipogon Griff 对 qHTB1–1QTL 进行精细定位，该 QTL 在孕穗阶段赋予耐热性。
DOI：
10.1007/s00122-020-03539-7
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发表时间：
2020-01-27
影响因子：
5.4
通讯作者：
Wan, Jianlin
中科院分区：
文献类型：
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作者：
Cao, Zhibin;Li, Yao;Wan, Jianlin
控制水稻孕穗期耐热性的关键信息qHTB1-1被精确定位在一个47.1 kb的区域，包含8个候选基因。两个位置候选基因在热胁迫下的表达水平发生了显著变化。孕穗期的高温胁迫有可能显著限制水稻产量。以栽培稻R53与野生普通野生稻HHT4的种间高级回交群体为材料，建立了一套染色体片段渐渗系，以阐明qHTB1-1耐热性QTL的遗传机制。利用单染色体片段导入系IL01-15建立二次群体，定位孕穗期1号染色体qHTB1-1的耐热性。利用BC5F2、BC5F3和BC5F4群体，我们首先确认了qHTB1-1，并验证了表型效应。QHTB1-1 QTL可解释BC5F2、BC5F3和BC5F4世代表型变异的13.1%、16.9%和17.8%。利用从较大的BC6F2和BC6F3群体中筛选的纯合重组子，qHTB1-1被精细定位在标记RM11633和RM11642之间的47.1 kb区域内。在该区域注释了8个推测的预测基因，预测了6个编码表达蛋白的基因。这6个基因的表达谱表明，与R53相比，LOC_Os01g53160和LOC_Os01g53220在IL01-15中热胁迫诱导作用较强。比较R53和IL01-15的LOC_Os01g53160和LOC_Os01g53220基因编码区的序列，发现外显子上分别有1个同义和2个非同义SNPs。我们的结果为鉴定qHTB1-1基因提供了依据，并表明与qHTB1-1基因连锁的标记可以通过分子标记辅助选择来提高水稻孕穗期的耐热性。
Key message The qHTB1-1 QTL, controlling heat tolerance at the booting stage in rice, was fine mapped to a 47.1 kb region containing eight candidate genes. Two positional candidate genes showed significant changes in expression levels under heat stress. High-temperature stress at the booting stage has the potential to significantly limit rice production. An interspecific advanced backcrossed population between the Oryza sativa L. cultivar R53 and the wild Oryza rufipogon Griff accession HHT4 was used as the source material to develop a set of chromosome segment introgression lines to elucidate the genetic mechanism of the qHTB1-1 QTL in heat tolerance. A single-chromosome-segment introgression line, IL01-15, was used to develop secondary populations for the mapping of qHTB1-1 on chromosome 1 for heat tolerance at the booting stage. Using the BC5F2, BC5F3, and BC5F4 populations, we first confirmed qHTB1-1 and validated the phenotypic effect. The qHTB1-1 QTL explained 13.1%, 16.9%, and 17.8% of the phenotypic variance observed in the BC5F2, BC5F3, and BC5F4 generations, respectively. Using homozygous recombinants screened from larger BC6F2 and BC6F3 populations, qHTB1-1 was fine mapped within a 47.1 kb region between markers RM11633 and RM11642. Eight putative predicted genes were annotated in the region, and six genes were predicted to encode expressed proteins. The expression patterns of these six genes demonstrated that LOC_Os01g53160 and LOC_Os01g53220 were highly induced by heat stress in IL01-15 compared to R53. Sequence comparison of the gene-coding regions of LOC_Os01g53160 and LOC_Os01g53220 between R53 and IL01-15 revealed one synonymous and two nonsynonymous SNPs in exons, respectively. Our results provide a basis for identifying the genes underlying qHTB1-1 and indicate that markers linked to the qHTB1-1 locus can be used to improve the heat tolerance of rice at the booting stage by marker-assisted selection.