title: Chlorella induces stomatal closure via NADPH oxidase-dependent ROS production and its effects on instantaneous water use efficiency in Vicia faba.
abstract: Reactive oxygen species (ROS) have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs). Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2) scavenger, catalase (CAT), significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi) in Vicia faba via a reduction in leaf transpiration rate (E) without a parallel reduction in net photosynthetic rate (Pn) assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Xu
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Pan
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Gen-Xuan
authors.initials: GX
authors.lastname: Wang
mesh_terms: D002374:Catalase / Q000378:metabolism; D002708:Chlorella / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D031307:Vicia faba / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D014867:Water; D006861:Hydrogen Peroxide; D010544:Peroxidases; D002374:Catalase; D009195:Peroxidase; D019255:NADPH Oxidases