Newly discovered weg1 mutation gene: vital for drought resistance in rice

by Francisco Escala III | Reprimo

Philippine Rice Research Institute (PhilRice) and Balik Scientist awardee scientist Dr. Nonawin Lucob-Agustin, along with researchers from Nagoya University in Japan, has discovered a mutation gene in rice that can help rice plants to survive drought.

Dr. Lucob-Agustin and her team of researchers discovered the wavy root elongation growth 1 (weg1) gene, a gene from mutants of rice variety called Taichung 65, that can support rice plants that are planted in lowlands and are reliant on rainfall for water irrigation. Due to its wavy root characteristic, the rice plant can support more water and nutrient uptake, as compared to the typical straight root characteristic.

The weg1 gene contributes to factors that help rice plants to be more drought-resistant. Foremost is, such as the production of more L-type lateral roots that have a higher order of branching leading to a bigger expansion of the root system than the S-type lateral roots. Other factors such as direct regulation of asymmetric cell elongation that causes growth of wavy parental root, and indirect regulation of highly developed lateral root emergence is also controlled by weg1. With that said, the mutation gene only affects the root formation of wavy roots and lateral roots, and does not affect any other root components. The research team also found high auxin levels at the outer curvatures of the wavy parental root, which likely induces the formation of L-type lateral roots.

These characteristics of the weg1 gene are favorable for rice plants in tropical countries (such as the Philippines) with seasonal drought and soil moisture fluctuations. Therefore, proliferation of the said gene, as a material for rice breeding can improve shoots under such conditions.

Dr. Lucob-Agustin noted that they are still on the development of lines using the weg1 gene to produce drought-resistant and high-yielding varieties of rice.

Dr. Lucob-Agustin is a graduate of BS Agriculture from the University of the Philippines, and has worked as a science research specialist for PhilRice before going to Nagoya for graduate studies. Lucob-Agustin holds a Ph.D. in Bioengineering Sciences, and specializes in plant physiology and breeding, abiotic stress tolerance, plant genetics and epigenetics.