A single seed treatment mediated through reactive oxygen species increases germination, growth performance, and abiotic stress tolerance in Arabidopsis and rice.

ABSTRACT

Hydroxyl radical (•OH) is considered to be the most damaging among reactive oxygen species. Although afew studies have reported on its effects on growth and stress adaptation of plants, no detailed studies have been performed using •OH in germination and early seedling growth under abiotic stresses. Here we report a single seed treatment with •OH on germination and seedling growth of Arabidopsis and rice under non-stressed (ambient) and various abiotic-stressed conditions (chilling, high temperature, heat, and salinity). The treatment resulted in faster seed germination and early seedling growth under non-stressed conditions, and, interestingly, these effects were more prominent under abiotic stresses. In addition, Arabidopsis seedlings from treated seeds showed faster root growth and developed more lateral roots. These results show apositive and potential practical use for •OH in model and crop plants for direct seeding in the field, as well as improvement of tolerance against emerging stresses. Abbreviations AUC area under curve; MGT mean germination time; t50 time to reach 50% germination; U7525 time for uniform germination from 25% to 75%; ROS reactive oxygen species; GSI germination speed index; SI stress index; DI dormancy index.