A D-lactate dehydrogenase from rice is involved in conferring tolerance to multiple abiotic stresses by maintaining cellular homeostasis

• Published in: Scientific reports 2020-07, Vol.10 (1), p.12835, Article 12835
• Main Authors: Jain, Muskan, Aggarwal, Sakshi, Nagar, Preeti, Tiwari, Roopam, Mustafiz, Ananda
• Format: Article
• Language: English
• Subjects: 631/337; 631/449; Abiotic stress; Antioxidants; Computer Simulation; D-Lactate dehydrogenase; Dehydrogenase; Dehydrogenases; Detoxification; E coli; Enzymes; Gene Expression; Homeostasis; Homeostasis - physiology; Humanities and Social Sciences; L-Lactate dehydrogenase; Lactate Dehydrogenases - genetics; Lactate Dehydrogenases - metabolism; Lactate Dehydrogenases - physiology; Lactic acid; Metabolites; multidisciplinary; Oryza - enzymology; Oryza - genetics; Oryza - metabolism; Oryza - physiology; Plant species; Pyruvaldehyde; Pyruvaldehyde - metabolism; Pyruvic acid; Reactive Oxygen Species - metabolism; Rice; Science; Science (multidisciplinary); Stress, Physiological - genetics; Transgenic plants; Yeasts
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-69742-0

D-lactate dehydrogenase (D-LDH) converts D-lactate (the end product of glyoxalase system) to pyruvate and thereby completes the detoxification process of methylglyoxal. D-LDH detoxifies and diverts the stress induced toxic metabolites, MG and D-lactate, towards energy production and thus, protects the cell from their deteriorating effects. In this study, a D-LDH enzyme from rice (OsD-LDH2, encoded by Os07g08950.1) was characterized for its role in abiotic stress tolerance. For this, a combination of in silico, molecular, genetic and biochemical approaches was used. The kinetic analysis revealed OsD-LDH2 to be the most efficient D-LDH enzyme in comparison to D-LDHs from other plant species. Heterologous overexpression of OsD-LDH2 provides tolerance against multiple abiotic stresses in E. coli , yeast and plant system. The analysis of D-LDH mutant and OsD-LDH2 overexpressing transgenic plants uncovered the crucial role of D-LDH in mitigation of abiotic stresses. OsD-LDH2 overexpressing plants maintained lower level of ROS and other toxic metabolites along with better functioning of antioxidant system. This is the first report on correlation of D-LDH with multiple abiotic stress tolerance. Overall, OsD-LDH2 emerged as a promising candidate which can open a new direction for engineering stress tolerant crop varieties by maintaining their growth and yield in unfavorable conditions.