The Role Of Nbald And Aly4Elicitor-Induced Hypersensitive Response And Stomatal Closure

Elicitors/pathogen-associated molecular patterns (PAMP) trigger the plant immune system, leading to rapid programmed cell death (hypersensitive cell death, HCD) and stomatal closure. Here, we describe the role of NbALD from Nicotiana benthamiana in response to three PAMPs:bacterial harpin, fungal Nep1, and oomycete boehmerin, induced HCD and stomatal closure via virus-induced gene silencing. And we study the role of ALY4from Arabidopsis thaliana in response to Nepl from Magnaporthe oryzae, induced HCD and stomatal closure. NbALD and ALY4can function in Nepl-induced HCD and stomatal closure.In our labratory virus-inducing gene silencing was used to screen NbALD in cDNA library of Nicotiania. benthamiana. Silencing of this gene compromises HCD triggered by Nep1from Magnaporthe oryzae. The role of NbALD in the response to three elicitors: bacterial harpin, fugnal Nepl, and oomycete INF1, is described here. Silencing of ALD compromises HCD and hydrogen peroxide accumulation induced by Nepl rather than harpin-and INF1-triggered HCD and hydrogen peroxide.ALD-silenced plants showed impaired Nepl-induced stomatal closure, decreased Nepl-promoted nitric oxide (NO) production in guard cells and a reduction in Nepl-induced resistance against Phytophthora nicotianae.NbALD regulated NO synthesis in response to hydrogen peroxide (H2O2) during Nepl-induced stomatal closure, the possible signaling of Nepl-induced stomatal closure was ALD-H2O2-NO-stomatal closure. Analyses of expression level showed that NbALD are involved in the SA, JA and ET signal pathway by QRT-PCR.Arabidopsis ALY4, a homolog of NbALY916,which silenced plants compromised HCD triggered by Nepl from Magnaporthe oryzae in Nicotiana benthamiana. In this study, we used biochemical and genetic approaches to analyze the function of ALY4in the regulation of Nepl-induced HCD and stomatal closure. aly4mutant leaf compromise HCD and hydrogen peroxide accumulation induced by Nepl. aly4mutant plants showed impaired Nepl-induced stomatal closure, decreased Nepl-promoted nitric oxide (NO) production in guard cells and a reduction in Nepl-induced resistance against Pseudomonas syringae pv. tomato (Pst) strain DC3000. ALY4regulated NO synthesis in response to hydrogen peroxide (H2O2) during Nepl-induced stomatal closure, the possible signaling of Nepl-induced stomatal closure is ALY4-H2O2-NO-stomatal closure. Analysis of expression level showed that ALY4are involved in the SA, JA and ET signal pathway by QRT-PCR. These suggest ALY4play essential roles in the Nepl-triggered HCD, stomatal closure and resistance against P. syringae.