Structure, allelic diversity and selection of Asr genes, candidate for drought tolerance, in Oryza sativa L. and wild relatives
Structure, allelic diversity and selection of Asr genes, candidate for drought tolerance, in Oryza sativa L. and wild relatives
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DOI：
10.1007/s00122-010-1348-z
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发表时间：
2010-08-01
影响因子：
5.4
通讯作者：
This, Dominique
中科院分区：
文献类型：
--
作者：
Philippe, Romain;Courtois, Brigitte;This, Dominique
Asr（阿坝，stress，ripening）基因是一个小的基因家族，可能参与植物的抗旱性。为了分析它们在水稻水分限制环境育种中的意义，对该基因家族进行了进一步的特征分析。该基因家族的基因组结构揭示了位于4条不同染色体上且具有相同外显子-内含子结构的6个成员。Asr基因家族中的6个成员是串联复制和全基因组复制相结合的结果，它们在水分胁迫下的差异调节可能涉及一些亚功能化。对204份世界水稻种质资源中4个成员的多态性进行了研究。野生近缘种14份（O. rufipogon和O.尼瓦拉）。Asr基因的核苷酸多样性总体上较低，但不同基因之间的差异较大，导致了不同形状的单倍型网络。使用了中性统计检验，并将其与来自另一项已发表研究的分布在整个基因组中的111个参考基因的分布进行了比较。Asr 3多样性在物种水平上表现为平衡选择，在热带粳稻亚群中表现为定向选择。本研究全面描述了水稻Asr家族的组成，并分析了4个Asr基因在水稻中的核苷酸和单倍型多样性。asr 3脱颖而出，成为最佳的潜在候选人。本研究为进一步研究该基因家族的遗传多态性与耐旱性状变异的关系奠定了基础。
Asr (ABA, stress, ripening) genes represent a small gene family potentially involved in drought tolerance in several plant species. To analyze their interest for rice breeding for water-limited environments, this gene family was characterized further. Genomic organization of the gene family reveals six members located on four different chromosomes and with the same exon-intron structure. The maintenance of six members of the Asr gene family, which are the result of combination between tandem duplication and whole genome duplication, and their differential regulation under water stress, involves probably some sub-functionalization. The polymorphism of four members was studied in a worldwide collection of 204 accessions of Oryza sativa L. and 14 accessions of wild relatives (O. rufipogon and O. nivara). The nucleotide diversity of the Asr genes was globally low, but contrasted for the different genes, leading to different shapes of haplotype networks. Statistical tests for neutrality were used and compared to their distribution in a set of 111 reference genes spread across the genome, derived from another published study. Asr3 diversity exhibited a pattern concordant with a balancing selection at the species level and with a directional selection in the tropical japonica sub-group. This study provides a thorough description of the organization of the Asr family, and the nucleotide and haplotype diversity of four Asr in Oryza sativa species. Asr3 stood out as the best potential candidate. The polymorphism detected here represents a first step towards an association study between genetic polymorphisms of this gene family and variation in drought tolerance traits.