Van der Does Dieuwertje, Boutrot Freddy, Engelsdorf Timo, Rhodes Jack, McKenna Joseph F, Vernhettes Samantha, Koevoets Iko, Tintor Nico, Veerabagu Manikandan, Miedes Eva, Segonzac Cécile, Roux Milena, Breda Alice S, Hardtke Christian S, Molina Antonio, Rep Martijn, Testerink Christa, Mouille Grégory, Höfte Herman, Hamann Thorsten, Zipfel Cyril
The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom.
Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
PLoS Genet. 2017 Jun 12;13(6):e1006832. doi: 10.1371/journal.pgen.1006832. eCollection 2017 Jun.
Plants actively perceive and respond to perturbations in their cell walls which arise during growth, biotic and abiotic stresses. However, few components involved in plant cell wall integrity sensing have been described to date. Using a reverse-genetic approach, we identified the Arabidopsis thaliana leucine-rich repeat receptor kinase MIK2 as an important regulator of cell wall damage responses triggered upon cellulose biosynthesis inhibition. Indeed, loss-of-function mik2 alleles are strongly affected in immune marker gene expression, jasmonic acid production and lignin deposition. MIK2 has both overlapping and distinct functions with THE1, a malectin-like receptor kinase previously proposed as cell wall integrity sensor. In addition, mik2 mutant plants exhibit enhanced leftward root skewing when grown on vertical plates. Notably, natural variation in MIK2 (also named LRR-KISS) has been correlated recently to mild salt stress tolerance, which we could confirm using our insertional alleles. Strikingly, both the increased root skewing and salt stress sensitivity phenotypes observed in the mik2 mutant are dependent on THE1. Finally, we found that MIK2 is required for resistance to the fungal root pathogen Fusarium oxysporum. Together, our data identify MIK2 as a novel component in cell wall integrity sensing and suggest that MIK2 is a nexus linking cell wall integrity sensing to growth and environmental cues.
植物能够积极感知并响应其细胞壁在生长、生物和非生物胁迫过程中出现的扰动。然而，迄今为止，很少有参与植物细胞壁完整性感知的成分被描述。我们采用反向遗传学方法，鉴定出拟南芥富含亮氨酸重复序列的受体激酶MIK2是纤维素生物合成抑制引发的细胞壁损伤反应的重要调节因子。事实上，功能缺失的mik2等位基因在免疫标记基因表达、茉莉酸产生和木质素沉积方面受到严重影响。MIK2与THE1具有重叠和不同的功能，THE1是一种先前被认为是细胞壁完整性传感器的类Malectin受体激酶。此外，mik2突变体植株在垂直平板上生长时表现出增强的向左根倾斜。值得注意的是，MIK2（也称为LRR-KISS）的自然变异最近与轻度盐胁迫耐受性相关，我们使用插入等位基因证实了这一点。令人惊讶的是，在mik2突变体中观察到的根倾斜增加和盐胁迫敏感性表型均依赖于THE1。最后，我们发现MIK2是抵抗真菌根病原体尖孢镰刀菌所必需的。总之，我们的数据将MIK2鉴定为细胞壁完整性感知中的一个新成分，并表明MIK2是将细胞壁完整性感知与生长和环境线索联系起来的一个枢纽。
