Temporal Regulation of Oxidative Window and Hormonal Homeostasis Are the Key Events Regulating Germination Under Salinity and Oxidative Stress

• Published in: Journal of plant growth regulation Vol. 42; no. 5; pp. 2907 - 2932
• Main Authors: Dey, Ananya, Bhattacharjee, Soumen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2023; Springer Nature B.V
• Subjects: Abscisic acid; Agriculture; Antioxidants; Ascorbic acid; Biomedical and Life Sciences; Catalase; Cultivars; Environmental stress; Gene expression; Gene regulation; Genotypes; Germination; Gibberellic acid; Glutathione; Homeostasis; Jasmonic acid; Life Sciences; Maintenance; Oryza sativa indica; Oxidative stress; Perturbation; Plant Anatomy/Development; Plant Physiology; Plant Sciences; Salinity; Salinity effects; Scavenging; Time dependence; Salinity stress; Oxidative stress; ROS–antioxidant interaction; Germination; RBOH–ascorbate–glutathione pathway; Hormonal homeostasis
• ISSN: 0721-7595; 1435-8107
• DOI: 10.1007/s00344-022-10756-5

Though some recent studies revealed the role oxidative window in determining the fate of germinating tissue, but till date there is no systematic study of temporal regulation of this process and their impact on hormonal homeostasis under environmental stress and hence is the subject of the present investigation. The present investigation with two contrasting genotypes of indica rice (Oryza sativa L., Cultivars IR29 and Pokkali) grown under salinity and oxidative stress, showed not only perturbation of normal temporal rhythm of ROS–antioxidant interaction dynamics but also exhibited more disruption for the salt sensitive cultivar IR 29 than salt resistant cultivar Pokkali. Efficacy and gene expression studies of central redox hub (integrated Rboh–ascorbate–glutathione/catalase pathway), radical scavenging property, further confirmed the role of time-dependent transition of internal redox cue with antioxidant-coupled redox buffering as a determinant of successful germination under unfavorable environmental cues studied. Assessment of transcript abundance of genes of Osrboh, OsSodCc2, OsCatA, OsAPx2, OsGRase further supported the transcriptional regulation of central redox hub necessary for the maintenance of internal redox cue during metabolic reactivation stage (48 h). Comparative assessment of pool of gibberellic acid, abscisic acid and jasmonic acid revealed a close connection between the ability of temporal redox management on restoration of hormonal homeostasis required for germination. A time-dependent alternation of ROS–antioxidant interaction dynamics and gene expression associated with the formation of redox cue and maintenance of hormonal homeostasis necessary for germination is suggested.