SCIENCE NEWS - May 18 (UPI) -- Scientists have identified several new genes responsible for root growth in tomato and rice plants. The discovery, described Tuesday in the journal Cell, could help scientists develop more drought-resistant crop varieties.
Root networks operate like a central nervous system, allowing plants to sense their surroundings. Plants use their roots to not only suss out the resources they need, water and nutrients, but also to identify environmental threats.
By analyzing gene expression data collected from tomato, rice and rockcress plants grown under a variety of conditions, researchers were able to identify a handful of genes responsible for recognizing and responding to drought conditions.
Specifically, researchers identified genes responsible for the production of xylem, small, tube-like vessels that pump water and nutrients from a plant's root up to its shoots.
"Xylem are very important to shore up plants against drought as well as salt and other stresses," lead study author Siobhan Brady, a professor of plant biology at the University of California, Davis, said in a press release.
Researchers also identified a group of genes that dictate the construction of lignin and suberin inside the outer layers of plant roots. Lignin and suberin form cork, which helps roots hold onto the water they capture.
"Suberin and lignin are natural forms of drought protection, and now that the genes that encode for them in this very specific layer of cells have been identified, these compounds can be enhanced," said study co-author Julia Bailey-Serres.
"I'm excited we've learned so much about the genes regulating this moisture barrier layer. It is so important for being able to improve drought tolerance for crops," said Bailey-Serres, a professor of genetics at the University of California, Riverside.
Additionally, researchers found the genes responsible for meristem were surprisingly similar among tomato, rice and rockcress, a cabbage relative commonly used as a plant model.
Meristem cells form the tips of roots and differentiate into a variety of tissue types.
"It's the region that's going to make the rest of the root, and serves as its stem cell niche," said Bailey-Serres. "It dictates the properties of the roots themselves, such as how big they get. Having knowledge of it can help us develop better root systems."
Scientists suspect the newly identified genes play similar roles across a variety of plant species. In followup studies, the researchers said they plan to test how these genes might be tweaked to boost drought resistance.