Disruption of OsLAT5 is sufficient to endow rice tolerance to dihydropyridine herbicides at commercial application concentrations

Abstract

Breeding 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, OsLAT1 was mainly responsible for root uptake and root-to-shoot transport; whereas, OsLAT5 was more responsible for intracellular transport to chloroplasts. The oslat5 disruption line tolerated relevant concentrations, while oslat1 did not. Compared to GY11 wild type, plant height, 1000-grain weight, and spermidine, spermine, and putrescine content changes occurred in GY11-oslat5 lines, implying involvement of OsLAT5 in yield and quality regulation. OsLAT5P44F, P44Y and P44R showed 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.