The Arabidopsis small G‐protein AtRAN1 is a positive regulator in chitin‐induced stomatal closure and disease resistance

Abstract

Plants coexist with diverse microorganisms, and their interactions have resulted in coevolution. Higher plants have immune systems with two different levels to resist pathogen invasion and multiplication. The gene-for-gene concept characterizes genetic control by plant resistance gene products and pathogen avirulence proteins, which are pathogen-secreted effectors that manipulate host processes in favour of the pathogen (Goehre & Robatzek, 2008; Gouveia et al., 2017; Wang et al., 2019); their direct or indirect molecular interactions initiate effector-triggered immunity (ETI), which is essential to conventional race-specific resistance breeding programmes (Peng et al., 2018). Moreover, microbial-originated invariant structures, known as microbial-associated molecular patterns (MAMPs), are able to activate pattern-triggered immunity (PTI) in various cultivars of numerous species, resulting in the elicitation of plant stomatal closure and disease resistance (Boller & He, 2009; Chisholm et al., 2006). Chitin is a polymer of N-acetyl-d-glucosamine that can be obtained from natural sources, such as arthropod exoskeletons or fungal cell walls. It is a PTI inducer that elicits stomatal closure and disease resistance, and has been applied to control crop disease (Liu et al.,

Overexpression of a small GTP‐binding protein Ran1 in Arabidopsis leads to promoted elongation growth and enhanced disease resistance against P. syringae DC3000

“…However, compared with the WT, atran1, Col-0&AtRAN1 Q72L -OE and atran2/3&AtRAN1 Q72L -OE plants exhibited severe chlorosis and necrotic cell death, but the AtRAN1-OE plants exhibited lower levels of chlorosis and necrotic cell death (Figure 5a,d). Interestingly, we found that the atran1 mutant was also more susceptible to the bacterial pathogen with higher ion leakage and lower chlorophyll content than Col-0 after Pst infection (Figure 5b-d), in agreement with a previous report (Song et al, 2020). To further investigate whether the necrotic cell death induced by Pst was related to the accumulation of reactive oxygen species (ROS), 3,3 0 -diaminobenzidine (DAB) staining was used to detect H 2 O 2 in WT, AtRAN1-OE, and AtRAN1 Q72L -OE plants after inoculation with Pst (Figure 5b and Figure S9).…”

A chromosome-scale genome and transcriptomic analysis of the endangered tropical treeVatica mangachapoi(Dipterocarpaceae)

“…4B ). Considering that the chitin-triggered immunity pathway is involved in stomatal regulation, 55 we suspect that this pathway may also regulate drought response in V. mangachapoi .…”

“…Therefore, AtRAN1 might positively regulate drought responses by mediating other stress response genes. 55 As the possibility of fungal infection in the samples used for the transcriptomic analyses cannot be completely excluded, it is unclear whether the increased expression of chitin-triggered genes was solely the result of drought stress or if fungal infection was involved, as well. However, since drought stress is tightly linked with susceptibility to infection, 55 genes responsible for stomatal control are likely involved in both abiotic and biotic stress responses.…”

“… 55 As the possibility of fungal infection in the samples used for the transcriptomic analyses cannot be completely excluded, it is unclear whether the increased expression of chitin-triggered genes was solely the result of drought stress or if fungal infection was involved, as well. However, since drought stress is tightly linked with susceptibility to infection, 55 genes responsible for stomatal control are likely involved in both abiotic and biotic stress responses. It is possible, then, that drought response pathways in V. mangachapoi are largely controlled by chitin-triggered immune response genes that regulate the opening and closing of the stomata, and consequently, reduce photosynthesis and transpiration.…”

Overexpressing the N‐terminus of CATALASE2 enhances plant jasmonic acid biosynthesis and resistance to necrotrophic pathogen Botrytis cinerea B05.10

“…Due to a sessile lifestyle, plants are constantly confronted with various biotic stresses, including fungal infection, bacterial invasion, and virus attack (Chaouch et al, 2010 ; Liu et al, 2020a ; Qi et al, 2012 ). During the long‐term evolution of the arms race with pathogens, plants have evolved sophisticated defence mechanisms to effectively ward off different kinds of pathogens (Li et al, 2020b ; Song et al, 2021 ; Yuan et al, 2017 ). Based on lifestyles, plant pathogens can be generally categorized into biotrophic and necrotrophic pathogens, which derive nutrients mainly from living host tissues or dead/dying cells, respectively (Qi et al, 2012 ; Spoel & Dong, 2008 ).…”