Aldo‐keto reductase enzymes detoxify glyphosate and improve herbicide resistance in plants

• Published in: Plant biotechnology journal Vol. 15; no. 7; pp. 794 - 804
• Main Authors: Vemanna, Ramu S., Vennapusa, Amaranatha Reddy, Easwaran, Murugesh, Chandrashekar, Babitha K., Rao, Hanumantha, Ghanti, Kirankumar, Sudhakar, Chinta, Mysore, Kirankumar S., Makarla, Udayakumar
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.07.2017; John Wiley and Sons Inc
• Subjects: Aldo-keto reductase; Aldo-Keto Reductases - metabolism; Arabidopsis thaliana; Biotechnology; Crops; Docking; Enzymes; Food; Genetically engineered foods; Genetically modified crops; Glycine - analogs & derivatives; Glycine - metabolism; Glycine - toxicity; Glyphosate; GM plants; Herbicide resistance; Herbicide Resistance - genetics; herbicide tolerance; Herbicides; Homology; Microorganisms; Nicotiana - drug effects; Nicotiana - enzymology; Nicotiana - genetics; Oryza - drug effects; Oryza - enzymology; Oryza - genetics; Photosynthesis; Photosynthesis - drug effects; Photosynthesis - physiology; Plants, Genetically Modified - drug effects; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Protein Binding - genetics; protein docking; Proteins; Pseudomonas - enzymology; Pseudomonas - genetics; Regeneration; residual toxicity; Rice; Seedlings; Shikimic acid; Shikimic Acid - metabolism; Tobacco; Transgenic plants; Weeds; Yeast; Yeasts; residual toxicity; transgenic plants; herbicide tolerance; protein docking; photosynthesis; GM plants; aldo-keto reductase; shikimic acid; glyphosate
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/pbi.12632

Summary In recent years, concerns about the use of glyphosate‐resistant crops have increased because of glyphosate residual levels in plants and development of herbicide‐resistant weeds. In spite of identifying glyphosate‐detoxifying genes from microorganisms, the plant mechanism to detoxify glyphosate has not been studied. We characterized an aldo‐keto reductase gene from Pseudomonas (PsAKR1) and rice (OsAKR1) and showed, by docking studies, both PsAKR1 and OsAKR1 can efficiently bind to glyphosate. Silencing AKR1 homologues in rice and Nicotiana benthamiana or mutation of AKR1 in yeast and Arabidopsis showed increased sensitivity to glyphosate. External application of AKR proteins rescued glyphosate‐mediated cucumber seedling growth inhibition. Regeneration of tobacco transgenic lines expressing PsAKR1 or OsAKRI on glyphosate suggests that AKR can be used as selectable marker to develop transgenic crops. PsAKR1‐ or OsAKRI‐expressing tobacco and rice transgenic plants showed improved tolerance to glyphosate with reduced accumulation of shikimic acid without affecting the normal photosynthetic rates. These results suggested that AKR1 when overexpressed detoxifies glyphosate in planta.