Requirement of vesicle-associated membrane protein 721 and 722 for sustained growth during immune responses in Arabidopsis
Requirement of vesicle-associated membrane protein 721 and 722 for sustained growth during immune responses in Arabidopsis
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DOI：
10.1007/s10059-013-2130-2
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发表时间：
2013-06-01
影响因子：
3.8
通讯作者：
Kwon, Chian
中科院分区：
文献类型：
--
作者：
Yun, Hye Sup;Kwaaitaal, Mark;Kwon, Chian
拟南芥中子囊菌和卵菌病原体的细胞外免疫反应依赖于 SNARE 蛋白 PEN1 突触蛋白、SNAP33 和内膜驻留 VAMP721/722 介导的囊泡相关分泌。功能性 GFP-VAMP722 在未受刺激的细胞中不断往返于质膜反映了 VAMP721/722 在植物生长和发育过程中组成型分泌中的第二个功能。细菌来源的激发子 flg22 的应用可稳定 VAMP721/722，否则这些 VAMP721/722 会通过 26S 蛋白酶体途径组成型降解。尽管VAMP721/722丰度升高，但通过降低VAMP721/722基因剂量来消除VAMP721/722水平会增强flg22诱导的幼苗生长抑制。因此，我们建议植物优先部署相应的分泌途径来防御植物的生长。有趣的是，VAMP721/722 在体外和体内与植物生长和抵抗细菌所需的质膜突触融合蛋白 SYP132 特异性相互作用。这表明植物生长/免疫相关的 VAMP721/722 与多个质膜突触蛋白形成 SNARE 复合物，以释放线索依赖性货物分子。
Extracellular immune responses to ascomycete and oomycete pathogens in Arabidopsis are dependent on vesicle-associated secretion mediated by the SNARE proteins PEN1 syntaxin, SNAP33 and endomembrane-resident VAMP721/722. Continuous movement of functional GFP-VAMP722 to and from the plasma membrane in non-stimulated cells reflects the second proposed function of VAMP721/722 in constitutive secretion during plant growth and development. Application of the bacterium-derived elicitor flg22 stabilizes VAMP721/722 that are otherwise constitutively degraded via the 26S proteasome pathway. Depletion of VAMP721/722 levels by reducing VAMP721/722 gene dosage enhances flg22-induced seedling growth inhibition in spite of elevated VAMP721/722 abundance. We therefore propose that plants prioritize the deployment of the corresponding secretory pathway for defense over plant growth. Interstingly, VAMP721/722 specifically interact in vitro and in vivo with the plasma membrane syntaxin SYP132 that is required for plant growth and resistance to bacteria. This suggests that the plant growth/immunity-involved VAMP721/722 form SNARE complexes with multiple plasma membrane syntaxins to discharge cue-dependent cargo molecules.