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热激蛋白90(heat shock protein 90,Hsp90)调控生物体的细胞代谢、生长发育和逆境适应等一系列生物过程。本研究通过c DNA末端快速扩增技术(rapid amplification of c DNA ends,RACE)分离获得了一个水稻干尖线虫(Aphelenchoides besseyi)Hsp90基因,命名为Ab-hsp90。Ab-hsp90全长c DNA序列含有69bp的5′非翻译区、编码712个氨基酸2 139 bp的开放阅读框以及137 bp的3′非翻译区UTR。Ab-hsp90DNA序列包含9个外显子和8个内含子。Ab-hsp90蛋白序列与其他植物寄生线虫Hsp90s高度相似,最大似然树显示与植物寄生线虫位于同一进化分支;结构上具有5个保守的Hps90蛋白家族序列标签和特异MEEVD基系,表明Ab-hsp90为胞质型Hsp90。q RT-PCR显示,Ab-hsp90在水稻干尖线虫各个龄期均表达,在卵和成虫表达水平最高。当线虫暴露于干燥、低渗透胁迫以及短时间阿维菌素溶液中时Ab-hsp90均上调表达;Ab-hsp90还受到短时低温(4℃)诱导,在高温(40℃)环境持续高水平表达。在侵染抗感不同的水稻(Oryza sativa)植株时,Ab-hsp90的表达水平具有差异性:在线虫接种抗性水稻72 h内,Ab-hsp90一直高度表达,而在接种感病水稻上Ab-hsp90表达水平显著升高随后下降。取食灰葡萄孢(Botrytis cinerea)的线虫Ab-hsp90在9 d内始终高度表达,而胡萝卜(Daucus carota)愈伤组织培养的线虫6 d内Ab-hsp90表达上调但此后逐渐下调。这些数据表明,Ab-hsp90可能参与水稻干尖线虫的抗逆适应、早期侵染以及取食行为。本研究有助于拓展植物寄生线虫Hsp90蛋白的功能,为进一步研究线虫与植物互作机制提供了有益借鉴。
Heat shock protein 90 (Hsp90) regulates a series of biological processes such as cellular metabolism, growth and development and adaptation to stress. In this study, a Hsp90 gene of Aphelenchoides besseyi was isolated by rapid amplification of c DNA ends (RACE) and named Ab-hsp90. The full-length c-DNA sequence of Ab-hsp90 contains a 69 bp 5 ’untranslated region encoding an open reading frame of 2 139 bp of 712 amino acids and a 137 bp 3’ untranslated region UTR. The Ab-hsp90 DNA sequence contains 9 exons and 8 introns. Ab-hsp90 protein sequence is highly similar to other plant parasitic nematodes Hsp90s, and the maximum likelihood tree is located in the same phylogenetic branch as the plant parasitic nematodes. It has five conserved Hps90 protein family sequence tags and a specific MEEVD system, indicating that Ab-hsp90 Cytoplasmic Hsp90. q RT-PCR showed that Ab-hsp90 was expressed at all stages of A.japonicus, and had the highest expression level in eggs and adults. Ab-hsp90 upregulated when nematodes were exposed to dry, low osmotic stress and short-term avermectin solution. Ab-hsp90 was also induced by short-term hypothermia (4 ℃) and maintained at a high level (40 ℃) expression. Ab-hsp90 expression levels were different between plants infected with resistant Oryza sativa: Ab-hsp90 was highly expressed in nematode-inoculated resistant rice within 72 h, whereas Ab-hsp90 was highly expressed on susceptible rice The level of -hsp90 expression increased significantly and then decreased. Ab-hsp90, a nematode fed on Botrytis cinerea, was highly expressed within 9 d, while Ab-hsp90 expression was up-regulated in Daucus carota callus within 6 d but gradually decreased thereafter. These data indicate that Ab-hsp90 may be involved in the anti-retrogradation, early infection and feeding behavior of Ap.napus. This study is helpful to expand the function of Hsp90 protein of plant parasitic nematode, which provides a useful reference for further studying the mechanism of nematode-plant interaction.