CRISPR-edited Rice Plants Get Major Boost in Grain Yield

A research team from Purdue University and the Chinese Academy of Sciences has developed a rice variety that produces 25-31 percent more grain using CRISPR-Cas9 gene editing technology.

The team, led by Jian-Kang Zhu, professor in the Department of Horticulture and Landscape Architecture at Purdue and director of the Shanghai Center for Plant Stress Biology at the Chinese Academy of Sciences, made mutations to 13 genes associated with abscisic acid, known to play roles in plant stress tolerance and suppression of growth. From the varieties that were developed, one variety exhibited a little change in stress tolerance, but produced 25% more grain in a field test in Shanghai, China, and 31% more in a field test conducted on China's Hainan Island.

The researchers silenced suites of pyrabactin resistance 1 (PYR1)/PYR1-like (PYL)/regulatory components of ABA receptor (ACAR) genes, or simply, PYL genes. These genes enhance tolerance of abiotic stresses, such as drought, soil salinity, and other environmental factors, but also inhibit growth. Knocking out one gene in the PYL family might not have much effect on stress tolerance or growth since redundant genes can provide a similar function. A specific knockout combination, however, led to a variety that uses just the right redundancies to hold onto its stress-tolerance characteristics but reduces the growth inhibition.

The improved rice plants came from a common research line. The team's next step is to to use CRISPR-Cas9 to edit the same genes in elite varieties of rice to determine if those will also show improved yields.

For more details, read the Purdue University Agriculture News.