Glutathione regulates enzymatic antioxidant defence with differential thiol content in perennial pepperweed and helps adapting to extreme environment

• Published in: Acta physiologiae plantarum Vol. 35; no. 8; pp. 2501 - 2511
• Main Authors: Kaur, Tarandeep, Bhat, Hilal A, Raina, Anuj, Koul, Sushma, Vyas, Dhiraj
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.08.2013; Springer Berlin Heidelberg
• Subjects: Agriculture; altitude; Biomedical and Life Sciences; buffers; enzymes; glutathione; homeostasis; hydrogen peroxide; isozymes; Lepidium latifolium; Life Sciences; metabolism; NADP (coenzyme); Original Paper; oxidation; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; proteins; redox potential; temperature; thiols; Antioxidant system; Redox potential; Phytofood; Glutathione
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-013-1286-x

Perennial pepperweed (Lepidium latifolium Linn.) is a preferred ‘phytofood’ that is available for the longest period of a year in Ladakh. Present study was undertaken to identify the mechanism of redox homeostasis and understand factors responsible for its biochemical superiority during low temperatures. Results reveal that despite the stressful environment at higher altitude, the cellular conditions are more reducing for this plant. The reducing environment is maintained by significant induction of GSH rather than changes in its oxidation state, which changes the redox potential by 12 mV. Lower ratio of NADP⁺/NADPH and induction of new antioxidative isozymes at Leh (3,505 m) suggest crucial role of redox regulation in adaptation. These new proteins have higher thiol content and could provide an efficient redox sensing mechanism in Lepidium latifolium that respond through GSH/NADPH redox buffers. In vitro feeding experiment suggested that GSH plays an important role in induction of antioxidant enzymes, which may not be the direct consequence of H₂O₂ accumulation. It needs to be further investigated whether its responsive redox metabolism has some role in its invasive growth in riparian plains of America.