title: Silencing of G proteins uncovers diversified plant responses when challenged by three elicitors in Nicotiana benthamiana.
abstract: Signalling through heterotrimeric G protein composed of α-, β- and γ-subunits is essential in numerous physiological processes. Here we show that this prototypical G protein complex acts mechanistically by controlling elicitor sensitivity towards hypersensitive response (HR) and stomatal closure in Nicotiana benthamiana. Gα-, Gβ1-, and Gβ2-silenced plants were generated using virus-induced gene silencing. All silenced plants were treated with Xanthomonas oryzae harpin, Magnaporthe oryzae Nep1 and Phytophthora boehmeriae boehmerin, respectively. HR was dramatically impaired in Gα- and Gβ2-silenced plants treated with harpin, indicating that harpin-, rather than Nep1- or boehmerin-triggered HR, is Gα- and Gβ2-dependent. Moreover, all Gα-, Gβ1- and Gβ2-silenced plants significantly impaired elicitor-induced stomatal closure, elicitor-promoted nitric oxide (NO) production and active oxygen species accumulation in guard cells. To our knowledge, this is the first report of Gα and Gβ subunits involvement in stomatal closure in response to elicitors. Furthermore, silencing of Gα, Gβ1 and Gβ2 has an effect on the transcription of plant defence-related genes when challenged by three elicitors. In conclusion, silencing of G protein subunits results in many interesting plant cell responses, revealing that plant immunity systems employ both conserved and distinct G protein pathways to sense elicitors from distinct phytopathogens formed during plant-microbe evolution.
authors: College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
authors: Huajian
authors: H
authors: Zhang
authors: Meifang
authors: M
authors: Wang
authors: Wei
authors: W
authors: Wang
authors: Deqing
authors: D
authors: Li
authors: Qian
authors: Q
authors: Huang
authors: Yuanchao
authors: Y
authors: Wang
authors: Xiaobo
authors: X
authors: Zheng
authors: Zhengguang
authors: Z
authors: Zhang
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D020868:Gene Silencing; D006706:Homeostasis; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D020082:Magnaporthe / Q000502:physiology; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D010838:Phytophthora / Q000502:physiology; D057865:Plant Immunity; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D054046:Plant Stomata / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D014026:Nicotiana / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D020798:Two-Hybrid System Techniques; D014974:Xanthomonas / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D005656:Fungal Proteins; D010940:Plant Proteins; D018749:RNA, Plant; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D019204:GTP-Binding Proteins