Submitted to: Plant Signaling and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2007
Publication Date: 11/1/2007
Citation: Sarath, G., Hou, G., Baird, L.M., Mitchell, R. 2007. Aba, ros and no are key players during switchgrass seed germination. Plant Signaling and Behavior. 2: 492-493.
Interpretive Summary: Seed dormancy and germination are complex physiological processes usually under hormonal control. In this paper we have developed a framework to understand the physiological, biochemical and molecular processes impacting switchgrass seed dormancy and germination. Our long term goal is to obtain uniform seed germination for good stand establishment under field conditions.
Technical Abstract: Seed dormancy and germination are complex physiological processes usually under hormonal control. Germination of seeds from many plants including switchgrass, are inhibited by ABA and promoted by NO and by ROS. However, ABA apparently requires both ROS and NO as intermediates in its action, with ROS produced by membrane-bound NADPH-oxidases responsive to ABA. In switchgrass seeds, externally supplied hydrogen peroxide (ROS), but not NO will overcome ABA-imposed inhibition of germination. Stimulation of germination by external ROS can be partially blocked by NO-scavengers, suggesting that NO is required for seed germination in switchgrass as well as for ABA-induced inhibition of germination. Collectively, these data suggest that multiple mechanisms might be required to sense and respond to varying levels of ABA, NO and ROS in switchgrass seeds.