Biotech Updates

Newly-discovered Rice Gene for Drought Resistance

August 7, 2013

An international team of crop scientists from Japan's National Institute of Agrobiological Sciences (NIAS) and the International Center for Tropical Agriculture (CIAT) have identified a gene in rice called Deeper Rooting 1 (DRO1) that gives plants deeper roots, resulting in triple yields during droughts. Rice is highly susceptible to drought because of its shallow roots, but the new study shows that by pointing roots down instead of sideways, the DRO1 gene results in roots that are nearly twice as deep as those of standard rice varieties.

The study's lead author Yusaku Uga, a researcher from NIAS, said "If rice adapts to or avoids drought conditions using deeper roots, it can get water and nutrients from the deep soil layers."

The team crossbred IR64, a high-yielding, but short-rooted and drought-prone commercial rice variety, with a deep-rooting upland rice variety from the Philippines, called Kinandang Patong. While IR64 already contains the DRO1 gene, it cannot produce the necessary proteins that enable the gene to function effectively. The scientists then combined the high yields of IR64, with the fully-functional DRO1 gene in Kinandang Patong.

The resulting plants had roots that were able to reach more than twice as deep as those of IR64. When tested under simulated conditions of moderate drought, IR64 yields were lessened by almost 60%, while the crossbreeds suffered only a 10% yield loss. Under extreme drought, IR64 completely failed, but the new rice plants continued to produce grain – about 30% of the yield of unstressed rice plants growing in normal conditions.

According to CIAT's Manabu Ishitani, "It's a very exciting discovery. We've known for some time that deeper roots can buy farmers extra time during periods of drought, but until now we haven't known which gene in rice is responsible for root architecture, or how to control it."

The results of this study have been published in the journal Nature Genetics available at: (doi:10.1038/ng.2725).

The news release from CIAT can be read at: