title: Stomata prioritize their responses to multiple biotic and abiotic signal inputs.
abstract: Stomata are microscopic pores in leaf epidermis that regulate gas exchange between plants and the environment. Being natural openings on the leaf surface, stomata also serve as ports for the invasion of foliar pathogenic bacteria. Each stomatal pore is enclosed by a pair of guard cells that are able to sense a wide spectrum of biotic and abiotic stresses and respond by precisely adjusting the pore width. However, it is not clear whether stomatal responses to simultaneously imposed biotic and abiotic signals are mutually dependent on each other. Here we show that a genetically engineered Escherichia coli strain DH5α could trigger stomatal closure in Vicia faba, an innate immune response that might depend on NADPH oxidase-mediated ROS burst. DH5α-induced stomatal closure could be abolished or disguised under certain environmental conditions like low [CO2], darkness, and drought, etc. Foliar spraying of high concentrations of ABA could reduce stomatal aperture in high humidity-treated faba bean plants. Consistently, the aggressive multiplication of DH5α bacteria in Vicia faba leaves under high humidity could be alleviated by exogenous application of ABA. Our data suggest that a successful colonization of bacteria on the leaf surface is correlated with stomatal aperture regulation by a specific set of environmental factors.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Ou
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China; School of Agriculture and Food Sciences, Zhejiang A&F University, Hangzhou, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gan
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Peilei
authors.initials: P
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Shaoxing University, Shaoxing, P. R. China.
authors.forename: Muqing
authors.initials: M
authors.lastname: Qiu
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Jiang
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Genxuan
authors.initials: G
authors.lastname: Wang
mesh_terms: D002245:Carbon Dioxide; D003624:Darkness; D055864:Droughts; D004926:Escherichia coli; D054884:Host-Pathogen Interactions; D006813:Humidity; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism; D054046:Plant Stomata / Q000382:microbiology / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological; D031307:Vicia faba / Q000382:microbiology / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D002245:Carbon Dioxide