Inset: Photo of roots that contain different dosages of a family of genes that affects root architecture, allowing wheat plants to grow longer roots and take in more water – Gilad Gabay / UC Davis.
The research team from the University of California, Davis has discovered that growing wheat in drought conditions may become easier in the future, thanks to their new genetic research. The team found that by stimulating longer root growth, wheat plants can pull water from deeper supplies. This results in plants with more biomass and higher grain yield, making them more resistant to low water conditions.
The study, published in the journal Nature Communications, provides new tools to modify wheat root architecture to withstand low water conditions. Gilad Gabay, a postdoctoral researcher in the Department of Plant Sciences at UC Davis and the first author on the paper, said that this finding is a useful tool to engineer root systems to improve yield under drought conditions in wheat.
According to the researchers, roots play a crucial role in plants as they absorb water and nutrients to support plant growth. The discovery of a gene family called OPRIII, and that different copies of these genes affect root length, is a significant step in understanding the genes that affect the root structure of wheat.
Distinguished Professor Jorge Dubcovsky, the project leader in the lab where Gabay works, said that the duplication of the OPRIII genes results in increased production of a plant hormone called Jasmonic acid that causes the accelerated production of lateral roots. Different dosages of these genes can be used to obtain different roots.
The researchers used CRISPR gene editing technology to eliminate some of the OPRIII genes duplicated in wheat lines with shorter roots. On the other hand, increasing the copies of these genes caused shorter and more branched roots. But inserting a rye chromosome resulted in decreased OPRIII wheat genes and longer roots.
Fine-tuning the dosage of the OPRIII genes can allow researchers to engineer root systems that are adapted to drought, normal conditions, and different scenarios. By knowing the right combination of genes, researchers can search for wheat varieties that have those natural variations and breed them for release to growers planting in low-water environments.
Losses from water stress can erase the improvements in wheat production. Thus, plants that can adapt to low water conditions while having increased yield will be crucial in growing enough food for a growing population in the face of global warming.
Contributors to the paper include researchers from UC Berkeley, Howard Hughes Medical Institute in Maryland, Fudan University in China, National University of San Martin in Argentina, China Agricultural University, Technological Institute of Chascomús in Argentina, University of Haifa in Israel, and UC Riverside Metabolomics Core Facility.
Funding for the researchers came from the BARD US-Israel Agricultural Research and Development Fund, U.S. Department of Agriculture, Howard Hughes Medical Institute, and National Natural Science Foundation of China.