title: A novel aldo-keto reductase from Jatropha curcas L. (JcAKR) plays a crucial role in the detoxification of methylglyoxal, a potent electrophile.
abstract: Abiotic stress leads to the generation of reactive oxygen species (ROS) which further results in the production of reactive carbonyls (RCs) including methylglyoxal (MG). MG, an α, β-dicarbonyl aldehyde, is highly toxic to plants and the mechanism behind its detoxification is not well understood. Aldo-keto reductases (AKRs) play a role in detoxification of reactive aldehydes and ketones. In the present study, we cloned and characterised a putative AKR from Jatropha curcas (JcAKR). Phylogenetically, it forms a small clade with AKRs of Glycine max and Rauwolfia serpentina. JcAKR was heterologously expressed in Escherichia coli BL-21(DE3) cells and the identity of the purified protein was confirmed through MALDI-TOF analysis. The recombinant protein had high enzyme activity and catalytic efficiency in assays containing MG as the substrate. Protein modelling and docking studies revealed MG was efficiently bound to JcAKR. Under progressive drought and salinity stress, the enzyme and transcript levels of JcAKR were higher in leaves compared to roots. Further, the bacterial and yeast cells expressing JcAKR showed more tolerance towards PEG (5%), NaCl (200mM) and MG (5mM) treatments compared to controls. In conclusion, our results project JcAKR as a possible and potential target in crop improvement for abiotic stress tolerance.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Shalini
authors.initials: S
authors.lastname: Mudalkar
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Rachapudi Venkata
authors.initials: RV
authors.lastname: Sreeharsha
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India. Electronic address: arrsl@uohyd.ernet.in.
authors.forename: Attipalli Ramachandra
authors.initials: AR
authors.lastname: Reddy
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics / Q000378:metabolism*; D000447:Aldehydes / Q000378:metabolism / Q000633:toxicity; D000074408:Aldo-Keto Reductases; D055864:Droughts; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D015870:Gene Expression; D031286:Jatropha / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D007659:Ketones / Q000378:metabolism / Q000633:toxicity; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D011092:Polyethylene Glycols / Q000378:metabolism; D011765:Pyruvaldehyde / Q000378:metabolism* / Q000633:toxicity; D011994:Recombinant Proteins; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological; D019076:Transgenes; D015003:Yeasts / Q000201:enzymology / Q000235:genetics / Q000502:physiology
chemical_list: D000447:Aldehydes; D007659:Ketones; D010940:Plant Proteins; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D011765:Pyruvaldehyde; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase
keywords: Abiotic stress tolerance; Aldo-keto reductase (AKR); Jatropha curcas; JcAKR; Methylglyoxal (MG); Reactive carbonyls (RCs)