Roots breakthrough: drought-resistant rice


Japanese biotechnologists have developed a rice plant with deeper roots that can sustain high yields in droughts that wipe out conventional rice crops.

It is the third breakthrough in new cereal strains in less than two years, boosting the quest to feed the world’s spiraling population as climate change worsens.

Writing in the journal Nature Genetics, a team led by Yusaku Uga of the National Institute of Agrobiological Sciences in Tsukuba, Ibaraki Prefecture, describes finding a remarkable gene in a rice plant cultivated in the dry uplands of the Philippines.

This strain, also called cultivar, is called Kinandang Patong. Its big characteristic is roots that are deep and grow straight downward, boring into parched soil for water, as opposed to root systems that are shallow and grow out laterally in typical water-rich paddy fields.

The gene for this — dubbed DRO1 for “deep rooting” — was spliced into a cultivar called IR64, a paddy rice plant grown around Asia.

The team then put the new plant through its paces, planting both it and standard IR64 in upland fields in three kinds of conditions — no drought, moderate drought and severe drought.

Moderate drought reduced yield of IR64 to just 42 percent in no-drought conditions. Severe drought destroyed it.

But IR64 with the DRO1 gene was almost unaffected by moderate drought. In severe drought, yield fell — but not catastrophically — by around 30 percent.

“Based on our results, this variety can be adapted to upland (agriculture) without irrigation,” Uga said in an email Sunday.

“We are also evaluating the DRO1 performance under rain-fed lowlands with the International Rice Research Institute,” he said. “If we can get positive results in farmers’ fields, we hope to release the variety for Asian countries. We are also going to introduce the DRO1 into leading varieties in Latin America with CIAT,” the International Center for Tropical Agriculture, he said.

Without genetic technology, it would have been extraordinarily hard to have pinpointed, and then inserted, the right gene, said Uga.