Plants have the ability to perceive drought. When they do, they emit a hormone that helps them hold on to water. This same hormone, ABA, sends a message to seeds that it isn't a good time to germinate, leading to lower crop yields and less food in places where it's hot -- an increasingly long list as a result of climate change. "If you block ABA, you mess with the chemical pathway that plants use to prevent seed germination," said Aditya Vaidya, UCR project scientist, and study author. "Our new chemical, Antabactin, does exactly this. If we apply it, we have shown that dormant seeds will sprout."
Demonstrations of Antabactin's effectiveness are described in a new paper published in the Proceedings of the National Academy of Sciences. This work builds on the same team's creation of a chemical that mimics the effects of the ABA hormone produced by plants in response to drought stress. That chemical, Opabactin, slows a plant's growth, so it conserves water and doesn't wilt. It works by inducing plants to close tiny pores in their leaves and stems, which prevents water from escaping.
Next, the team wanted to find a molecule that would have the opposite effect, opening the pores, encouraging germination, and increasing plant growth. Though seed dormancy has largely been removed through breeding, it is still a problem in some crops like lettuce.
Sean Cutler, a UCR plant cell biology professor and study co-author, said accelerating and slowing plant growth are important tools for farmers. "Our research is all about managing both of these needs," he said. To find Opabactin's opposite, Vaidya quickly made 4,000 derivatives of it. "He found a needle in the chemical haystack," Cutler said, "The compound he created blocks receptors to ABA, and is unusually potent."
"We hope to identify key molecular players that govern seed dormancy, ultimately reducing the impact of lost crop yields due to unfortunately timed plantings or poor seed germination," Vaidya said.
Read the complete research at www.sciencedaily.com.
Aditya S. Vaidya, Francis C. Peterson, James Eckhardt, Zenan Xing, Sang-Youl Park, Wim Dejonghe, Jun Takeuchi, Oded Pri-Tal, Julianna Faria, Dezi Elzinga, Brian F. Volkman, Yasushi Todoroki, Assaf Mosquna, Masanori Okamoto, Sean R. Cutler. Click-to-lead design of a picomolar ABA receptor antagonist with potent activity in vivo. Proceedings of the National Academy of Sciences, 2021; 118 (38): e2108281118 DOI: 10.1073/pnas.2108281118