The GHKL ATPase MORC1 Modulates Species-Specific Plant Immunity in Solanaceae.
The GHKL ATPase MORC1 Modulates Species-Specific Plant Immunity in Solanaceae.
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DOI：
10.1094/mpmi-12-14-0401-r
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发表时间：
2015-07
期刊：
影响因子：
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通讯作者：
P. Manosalva;M. Manohar;K. Kogel;Hong-Gu Kang;D. Klessig
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作者：
P. Manosalva;M. Manohar;K. Kogel;Hong-Gu Kang;D. Klessig
MERC蛋白是GHKL ATPase超家族的一个亚类，最近被描述为参与拟南芥转录基因沉默和植物免疫的成分。为了评估MORC1在茄科植物对马铃薯晚疫病菌抗性中的作用，我们改变了相应的MORC1同源物在马铃薯、番茄和本田烟草中的表达。在StMORC1沉默的马铃薯中，对致病疫霉的基本抗性降低，而在过度表达的马铃薯中增强，这表明StMORC1对免疫有积极的影响。相反，在番茄中沉默SlMORC1的表达或在本氏拟青霉中沉默NbMORC1的表达增强了对该卵菌的基本抗性。此外，沉默SLMORC1进一步增强了番茄对两个抗性基因的抗性。StMORC1瞬时表达可加速Inf1诱导的细胞死亡，而SLMORC1或NbMORC1可抑制Inf1诱导的细胞死亡。结构域交换和突变分析表明，在INF1诱导的细胞死亡中，C-末端决定了茄科MORC1蛋白的物种特异性效应。这个C末端区域也是重组StMORC1和SLMORC1同源二聚和磷酸化所必需的，它的瞬时表达诱导了本氏新月藻细胞的自发性死亡。因此，该C末端区域可能在决定和调节MORC1蛋白的生物活性方面发挥重要作用。
The microrchidia (MORC) proteins, a subset of the GHKL ATPase superfamily, were recently described as components involved in transcriptional gene silencing and plant immunity in Arabidopsis. To assess the role of MORC1 during resistance to Phytophthora infestans in solanaceous species, we altered the expression of the corresponding MORC1 homologs in potato, tomato, and Nicotiana benthamiana. Basal resistance to P. infestans was compromised in StMORC1-silenced potato and enhanced in overexpressing lines, indicating that StMORC1 positively affects immunity. By contrast, silencing SlMORC1 expression in tomato or NbMORC1 expression in N. benthamiana enhanced basal resistance to this oomycete pathogen. In addition, silencing SlMORC1 further enhanced resistance conferred by two resistance genes in tomato. Transient expression of StMORC1 in N. benthamiana accelerated cell death induced by infestin1 (INF1), whereas SlMORC1 or NbMORC1 suppressed it. Domain-swapping and mutational analyses indicated that the C-terminal region dictates the species-specific effects of the solanaceous MORC1 proteins on INF1-induced cell death. This C-terminal region also was required for homodimerization and phosphorylation of recombinant StMORC1 and SlMORC1, and its transient expression induced spontaneous cell death in N. benthamiana. Thus, this C-terminal region likely plays important roles in both determining and modulating the biological activity of MORC1 proteins.