Isolation and molecular analysis of genes Stpk-V2 and Stpk-V3 homologous to powdery mildew resistance gene Stpk-V in a Dasypyrum villosum accession and its derivatives
Isolation and molecular analysis of genes Stpk-V2 and Stpk-V3 homologous to powdery mildew resistance gene Stpk-V in a Dasypyrum villosum accession and its derivatives
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DOI：
10.1007/s13353-013-0172-y
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发表时间：
2013-10
影响因子：
2.4
通讯作者：
Z. Lin;Y. Zhang;M. J. Wang;J. Li;K. Wang;X. Chen;Q. Xu;X. Zhang;X. Ye
中科院分区：
文献类型：
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作者：
Z. Lin;Y. Zhang;M. J. Wang;J. Li;K. Wang;X. Chen;Q. Xu;X. Zhang;X. Ye
小麦-灰霉易位染色体T6V#2S•6AL和T6V#4S•6DL对小麦白粉病（PM）具有优异的抗性。然而，由于迄今尚未发现PM耐药基因的毒力，因此很难通过多病型检测来区分PM耐药基因的两个来源。为了揭示这两个易位中PM抗性基因之间的关系，我们以白粉病抗性locusPm21的关键成员stpk - vgene的序列为参考，从aD中分离出同源基因。紫茉莉1026号及其衍生物6v# 4（6D）二体取代（DS）系RW15和t6v# 4S•6DL易位系Pm97033。从No.1026中克隆出两个基因stpk - v2和stpk - v3。序列比对结果表明，stpk - v2和stpk - v3与stpk - v具有98.2%和96.2%的DNA同源性，99.3%和100%的氨基酸同源性。与stpk - v相比，在stpk - v2和stpk - v3的内含子4上分别发现了一个22 bp的直接序列重复和一个微型逆重复转座元件（MITE）。而在DS系RW15和易位系Pm97033中均未发现stpk - v2的存在，说明stpk - v2对RW15和Pm97033的抗PM性没有贡献。在启动子区域，不仅发现了一个78bp的插入，而且在其同源基因的小麦中也发现了一个78bp的插入。此外，与stpk - v /Stpk-V2相比，stpk - v3的推定启动子中有17 bp/8 bp的缺失/插入。实时定量RT-PCR分析表明，stpk - vandstpk - v3基因在易位系中表达水平受病原菌诱导，但接种bgt后12 h， stpk - v_1的表达水平高于stpk - v3_1。stpk - vgene的多样性将为小麦品种选育提供新的抗性基因。
Wheat-Dasypyrum villosumtranslocated chromosomes T6V#2S•6AL and T6V#4S•6DL are known to confer excellent resistance to wheat powdery mildew (PM). However, it is difficult to distinguish the two sources of PM resistance genes through multi-pathotype testing because to date no virulence for them has been found. To reveal the relationship between the PM resistance genes from the two translocations, the sequence of theStpk-Vgene, a key member of powdery mildew resistance locusPm21, was used as a reference to isolate homologous genes from aD. villosumaccession No.1026 and its derivatives 6V#4(6D) disomic substitution (DS) line RW15 and T6V#4S•6DL translocation line Pm97033. Two genesStpk-V2andStpk-V3were cloned from No.1026. Sequence alignment showed thatStpk-V2andStpk-V3shared 98.2 % and 96.2 % of their DNA and 99.3 % and 100 % of their amino acids in identity withStpk-V. Compared withStpk-V, a 22-bp direct sequence repeat and a miniature inverted-repeat transposable element (MITE) were found in the intron 4 ofStpk-V2andStpk-V3, respectively. However,Stpk-V2was not present in DS line RW15 and translocation line Pm97033 based on the PCR result, indicating thatStpk-V2did not contribute to the PM resistance of RW15 and Pm97033. In the promoter region, a 78-bp insertion was found not only inStpk-V2andStpk-V3, but also in its orthologous geneStpk-Aof wheat. In addition, there was a 17 bp/8 bp deletion/insertion in the putative promoter ofStpk-V3in comparison with that ofStpk-V/Stpk-V2. Real-time quantitative RT-PCR analysis indicated that the expression levels ofStpk-VandStpk-V3genes in the translocation lines were induced by the pathogen, butStpk-Vhad a higher expression level thanStpk-V3at 12 h after inoculation withBgt. The diversity ofStpk-Vgene will help to explore new resistance genes to PM inD. villosumfor wheat breeding.