Disruption ofOsLAT5is sufficient to endow rice tolerance to dihydropyridine herbicides at commercial application concentrations

Abstract

AbstractBreeding non-selective herbicide-resistant crops is important constituent of weed management system in modern rice production. Non-selective dihydropyridine herbicide shares transporters with polyamine (PA), making construction of a dihydropyridine herbicide-resistant rice line possible by inactivating the PA transporter function via gene editing. Success depends on understanding substrate selection for homologues in the PA transporter family and amino acid sites that play critical roles. Here,OsLAT1was mainly responsible for root uptake and root-to-shoot transport; whereas,OsLAT5was more responsible for intracellular transport to chloroplasts. Theoslat5disruption line tolerated relevant concentrations, whileoslat1did not. Compared to GY11 wild type, plant height, 1000-grain weight, and spermidine, spermine, and putrescine content changes occurred inGY11-oslat5lines, implying involvement ofOsLAT5in yield and quality regulation.OsLAT5P44F, P44Y and P44Rshowed declined dihydropyridine herbicide uptake but no spermidine and putrescine transport competence disruption in yeast, providing a candidate site for precisely editing in breeding a dihydropyridine herbicide-resistant rice cultivar without impairing rice yield and grain quality.