CLE9 peptide‐induced stomatal closure is mediated by abscisic acid, hydrogen peroxide, and nitric oxide in Arabidopsis thaliana

Abstract

CLE peptides have been implicated in various developmental processes of plants and mediate their responses to environmental stimuli. However, the biological relevance of most CLE genes remains to be functionally characterized. Here, we report that CLE9, which is expressed in stomata, acts as an essential regulator in the induction of stomatal closure. Exogenous application of CLE9 peptides or overexpression of CLE9 effectively led to stomatal closure and enhanced drought tolerance, whereas CLE9 loss-of-function mutants were sensitivity to drought stress. CLE9-induced stomatal closure was impaired in abscisic acid (ABA)-deficient mutants, indicating that ABA is required for CLE9-medaited guard cell signalling. We further deciphered that two guard cell ABA-signalling components, OST1 and SLAC1, were responsible for CLE9-induced stomatal closure. MPK3 and MPK6 were activated by the CLE9 peptide, and CLE9 peptides failed to close stomata in mpk3 and mpk6 mutants. In addition, CLE9 peptides stimulated the induction of hydrogen peroxide (H 2 O 2 ) and nitric oxide (NO) synthesis associated with stomatal closure, which was abolished in the NADPH oxidase-deficient mutants or nitric reductase mutants, respectively. Collectively, our results reveal a novel ABA-dependent function of CLE9 in the regulation of stomatal apertures, thereby suggesting a potential role of CLE9 in the stress acclimatization of plants.

NO and ABA Interaction Regulates Tuber Dormancy and Sprouting in Potato

“…NO plays a role in numerous plant physiological processes (Begara-Morales et al, 2019), such as transport (Sun et al, 2018), germination (Liu et al, 2010;Arc et al, 2013a), flowering (Khurana et al, 2011), metabolism (Hasanuzzaman et al, 2018), and senescence (Sun, 2018). Moreover, NO is a significant signaling molecule that regulates the plant response to various nonbiological and biological stresses (Begara-Morales et al, 2018), such as stomatal closure (Zhang et al, 2019), heat stress (Parankusam et al, 2017), disease (Srinivas et al, 2014), drought (Wang et al, 2016), and programmed cell death (Ma et al, 2010). Exogenous NO treatment was reported to break dormancy and promote germination in seeds of three warmseasons C 4 grasses (Sarath et al, 2006).…”

“…Some researchers have demonstrated interaction between NO signal transduction and ABA (Zhang et al, 2007;Arc et al, 2013a). For example, NO was involved in stomatal closure induced by ABA (Zhang et al, 2019). However, the crosstalk between NO and ABA in potato tuber dormancy and sprouting currently remains unclear.…”

Quick selenium accumulation in the selenium-rich rice and its physiological responses in changing selenium environments

“…The production of Reactive oxygen species in response to Se ROS has been considered to mediate the primary response of plant resistance to environmental toxicity [22][23][24]. Thus, we reasoned that ROS signaling might be involved in rice response to Se toxicity during long-term exposure.…”

Comparative transcriptome analysis revealed the cooperative regulation of sucrose and IAA on adventitious root formation in lotus (Nelumbo nucifera Gaertn)

“…The mRNA expression of nine genes and miRNAs at three time points (C0 stage: germinated seeds, C1 stage: day 1 post-treatment, C2: day 3 post-treatment) was quantified after treatment with 20 mg/L or 60 mg/L sucrose. The gene expression was analyzed using quantitative polymerase chain reaction (qPCR) as described previously [12,60]. The total RNA from the plant was extracted using the RNA extraction mini kit (QIAGEN, Germany).…”