Modern biology can speed crop improvements. Plant geneticists like 黑料吃瓜资源 (CSHL) Professor David Jackson can pinpoint factors that control plants鈥� health and development, then fine-tune them in a lab to optimize features like productivity, growth efficiency, and climate resilience. The approach is particularly powerful because, as Jackson and colleagues recently demonstrated in a study of both corn and rice, when researchers figure out how to adjust a trait at its genetic source, lessons from one plant may be applied to the improvement of another.
What鈥檚 good for one plant may be good for another
Much of the work in Jackson鈥檚 lab focuses on corn, one of the world鈥檚 most abundant crops. The world produced more than one billion metric tonnes of corn in 2019. With genetic adjustments devised by Jackson and his collaborators, yield could rise. Jackson and colleagues in China have found that a gene called KRN2 limits how many rows of kernels a corn cob can produce. Eliminating that gene leads to more kernels, increasing yield by ten percent. It鈥檚 one of multiple genetic strategies for increasing productivity.
The corn that feeds the world comes from a wide variety of corn strains. A variety that thrives in the industrial farms of the midwestern United States is unlikely to grow well in a field in Oaxaca, Mexico, where the soil, climate, and pathogens are different鈥攂ut thanks to corn鈥檚 genetic diversity, there鈥檚 another that will. 鈥淭here are thousands of varieties of corn that are grown around the world, and they’re all locally adapted,鈥� Jackson says. But the plants share enough genetics that many of them could respond similarly to the specific modifications that Jackson and his collaborators have found can increase yield. With the quick and efficient gene-editing tool CRISPR, it鈥檚 easy to find out.
鈥淭he advantage of this kind of CRISPR approach is that you could take a variety from a different country, anywhere, and just knock out this one KRN2 gene and potentially increase its yield,鈥� Jackson says.
Moving beyond corn
Better yet, what works in corn can work in other grains, too. In March, Jackson and his collaborators reported in Science that eliminating KRN2 causes rice plants to produce more branches on their seed-producing inflorescence. That allows more grains to develop, producing a larger harvest. Like corn, rice is diverse, and researchers will need to experiment to find out which varieties can be made more prolific by eliminating KRN2.
While farmers have taken advantage of plants鈥� natural diversity to grow foods suited to local conditions and preferences, certain traits are essential for agriculture. As wild plants were domesticated, growers favored those that could be grown and harvested reliably. When selecting for critical traits, breeders coaxed certain genetic similarities out of the plants we now rely on for food. Those similarities could make it easier for researchers to introduce improvements that are successful in one crop, like corn, into an entirely new plant.
鈥淚 talk to a lot of people in companies鈥攖hey want to use CRISPR to improve crops,鈥� Jackson says. 鈥淎nd their first question for me is, what should I target? Which gene should I pick and which is going to be the one that’s going to improve the yield? That’s been a major sticking point, knowing how to apply the technology鈥攚hich genes to tweak.鈥�
In their recent work with corn and rice, Jackson鈥檚 collaborators identified nearly 500 genes that, like KRN2, have been selected by breeders in both plants. That could help scientists take advantage of what鈥檚 known about corn to identify targets for gene editing to potentially improve rice plants. Meanwhile, Jackson鈥檚 lab is looking for regions outside of genes, in regulatory parts of the genome, that are shared between different species of plants. With CRISPR, Jackson says, it will be easy to test both kinds of targets to find ways to improve crops鈥� agronomic traits. 鈥淚 think CRISPR is going to have a huge impact on agriculture,鈥� he says, 鈥渁nd not only on yield, but hopefully in making agriculture more sustainable.鈥�
Editor鈥檚 note
David Jackson鈥檚 work in corn carries on a long tradition of maize genetics research at 黑料吃瓜资源 that began with George Shull in the early 1900s and continued mid-century with Nobelist Barbara McClintock. Plus, it gives him the opportunity to get outside, working in the fields in the summertime. Jackson is also a visiting professor at Huazhong Agricultural University in Wuhan, China. He travels frequently to China to collaborate with colleagues in Wuhan and Beijing.
Written by: Jennifer Michalowski, Science Writer | [email protected] | 516-367-8455
