title: The microbe-secreted isopeptide poly-γ-glutamic acid induces stress tolerance in Brassica napus L. seedlings by activating crosstalk between H2O2and Ca2.
abstract: Poly-γ-glutamic acid (γ-PGA) is a microbe-secreted isopeptide that has been shown to promote growth and enhance stress tolerance in crops. However, its site of action and downstream signaling pathways are still unknown. In this study, we investigated γ-PGA-induced tolerance to salt and cold stresses in Brassica napus L. seedlings. Fluorescent labeling of γ-PGA was used to locate the site of its activity in root protoplasts. The relationship between γ-PGA-induced stress tolerance and two signal molecules, H2O2and Ca2+, as well as the γ-PGA-elicited signaling pathway at the whole plant level, were explored. Fluorescent labeling showed that γ-PGA did not enter the cytoplasm but instead attached to the surface of root protoplasm. Here, it triggered a burst of H2O2in roots by enhancing the transcription of RbohD and RbohF, and the elicited H2O2further activated an influx of Ca2+into root cells. Ca2+signaling was transmitted via the stem from roots to leaves, where it elicited a fresh burst of H2O2, thus promoting plant growth and enhancing stress tolerance. On the basis of these observation, we propose that γ-PGA mediates stress tolerance in Brassica napus seedlings by activating an H2O2burst and subsequent crosstalk between H2O2and Ca2+signaling.
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lei
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Pang
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Feng
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Sha
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Chi
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Zongqi
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.|Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
mesh_terms: D000220:Adaptation, Biological; D001692:Biological Transport; D029688:Brassica napus / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D003080:Cold Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism; D010641:Phenotype; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D055049:Salt Tolerance; D036226:Seedlings / Q000254:growth & development* / Q000378:metabolism*; D015398:Signal Transduction; D012965:Sodium Chloride; D013312:Stress, Physiological
chemical_list: C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D002118:Calcium