title: Chlorella triggers stomatal closure mediated by NADPH oxidase and improves instantaneous water use efficiency in Vicia faba.
abstract: Stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs) has been associated with early defense responses of plants. Chlorella is a unicellular autotrophic microorganism that can synthesize many bioactive substances with positive effects on humans, animals and plants. However, its effects on stomatal movement and instantaneous intrinsic water use efficiency (WUEi) in plants have been not explored yet. Our present work showed that application of Chlorella to isolated epidermal peels of Vicia faba induced stomatal closure in a dose-and time-dependent manner. Pharmacological study revealed that the Chlorella-triggered stomatal closure was mainly mediated by reactive oxygen species (ROS) production via NADPH oxidase. Additionally, exogenous application of optimal concentrations of Chlorella suspension caused an obvious reduction in leaf transpiration rate (E) without a parallel reduction in net photosynthetic rate (Pn), favoring the improvement of WUEiin Vicia faba. The chlorophyll fluorescence and content analysis further indicated that Chlorella had no effects on plant photosynthetic reactions center after short-term foliar application.
authors.affiliation: Institute of Ecology; College of Life Sciences: Zhejiang University; Hangzhou, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Ecology; College of Life Sciences: Zhejiang University; Hangzhou, PR China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Xu
authors.affiliation: Institute of Ecology; College of Life Sciences: Zhejiang University; Hangzhou, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.affiliation: Institute of Ecology; College of Life Sciences: Zhejiang University; Hangzhou, PR China.
authors.forename: Sha
authors.initials: S
authors.lastname: Pan
authors.affiliation: Institute of Ecology; College of Life Sciences: Zhejiang University; Hangzhou, PR China.
authors.forename: Gen-Xuan
authors.initials: GX
authors.lastname: Wang
keywords: Chlorella vulgaris; ROS production; Viciafaba; chlorophyll fluorescence; stomatal closure