IGI Scientists Make Strides in Protecting Rice from Drought

Brian Staskawicz, Director of Innovative Genomics Institute (IGI) Sustainable Agriculture, together with his research team have used CRISPR to open a new path towards developing drought tolerant rice.

The gene STOMAGEN (short for “stomata generator”) is crucial for the development of stomata. Researchers have previously reduced the number of stomata by disabling or “knocking out” the STOMAGEN gene in rice, leading to an ~80% reduction in the number of stomata. Reducing the number of stomata could improve water use efficiency, but it also dramatically reduces the plant's ability to exchange carbon dioxide and oxygen that drives photosynthesis, plant growth, and plant yield. However, in rice, there is a copy, or paralog, of the STOMAGEN gene called EPFL10, with an almost identical genetic code. The team decided to investigate whether EPFL10 might be the solution.

Using CRISPR, Nicholas Karavolias and colleagues were able to compare STOMAGEN and EPFL10. They found that like STOMAGEN, EPFL10 promotes the development of stomata in rice leaves. However, its effects are milder and knocking out EPFL10 reduces the number of stomata, but less dramatically than knocking out STOMAGEN.

In the team's other experiments, the STOMAGEN knock-out negatively affected gas exchange. The team also observed that STOMAGEN knockouts had trouble regulating leaf temperature in some conditions, while EPFL10 knockouts were able to regulate their temperature as well as unedited plants in every condition tested. Finally, the research team did not observe any yield differences between the rice lines.

For more details, read the article in IGI News.