title: ROS Homeostasis Regulates Somatic Embryogenesis via the Regulation of Auxin Signaling in Cotton.
abstract: Somatic embryogenesis (S.E.) is a versatile model for understanding the mechanisms of plant embryogenesis and a useful tool for plant propagation. To decipher the intricate molecular program and potentially to control the parameters affecting the frequency of S.E., a proteomics approach based on two-dimensional gel electrophoresis (2-DE) combined with MALDI-TOF/TOF was used. A total of 149 unique differentially expressed proteins (DEPs) were identified at different stages of cotton S.E. compared with the initial control (0 h explants). The expression profile and functional annotation of these DEPs revealed that S.E. activated stress-related proteins, including several reactive oxygen species (ROS)-scavenging enzymes. Proteins implicated in metabolic, developmental, and reproductive processes were also identified. Further experiments were performed to confirm the role of ROS-scavenging enzymes, suggesting the involvement of ROS homeostasis during S.E. in cotton. Suppressing the expression of specifically identified GhAPX proteins resulted in the inhibition of dedifferentiation. Accelerated redifferentiation was observed in the suppression lines of GhAPXs or GhGSTL3 in parallel with the alteration of endogenous ascorbate metabolism and accumulation of endogenous H2O2 content. Moreover, disrupting endogenous redox homeostasis through the application of high concentrations of DPI, H2O2, BSO, or GSH inhibited the dedifferentiation of cotton explants. Mild oxidation induced through BSO treatment facilitated the transition from embryogenic calluses (ECs) to somatic embryos. Meanwhile, auxin homeostasis was altered through the perturbation of ROS homeostasis by chemical treatments or suppression of ROS-scavenging proteins, along with the activating/suppressing the transcription of genes related to auxin transportation and signaling. These results show that stress responses are activated during S.E. and may regulate the ROS homeostasis by interacting with auxin signaling.
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Ting
authors.initials: T
authors.lastname: Zhou
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Xiyan
authors.initials: X
authors.lastname: Yang
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Jinwu
authors.initials: J
authors.lastname: Deng
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Jiao
authors.initials: J
authors.lastname: Xu
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China;
authors.forename: Wenhui
authors.initials: W
authors.lastname: Gao
authors.affiliation: §Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, United Kingdom.
authors.forename: Keith
authors.initials: K
authors.lastname: Lindsey
authors.affiliation: From the ‡National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China; xlzhang@mail.hzau.edu.cn.
authors.forename: Xianlong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D015180:Electrophoresis, Gel, Two-Dimensional; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D003368:Gossypium / Q000196:embryology* / Q000378:metabolism; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D058439:Plant Somatic Embryogenesis Techniques; D040901:Proteomics / Q000379:methods*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013312:Stress, Physiological
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D017382:Reactive Oxygen Species