Scientists create gene mutations that alter the morphology and physiology of cells, causing rice leaves to curl in sunny weather, thereby reducing water loss.
A research team from the China Rice Research Institute, in collaboration with the University of California, Berkeley, discovered the PSL1 gene mutation that directly affects rice plants, making the leaf blades sensitive and prone to curling in low humidity and high sunlight environments, which helps enhance the drought resistance of rice plants.
Curled rice leaves in high sunlight temperatures. (Photo: China News).
Curled rice leaves are the result of changes in the morphology and physiology of the spindle-shaped cells located on the rice plant’s epidermis. Zhang Guangheng, a researcher at the China Rice Research Institute, stated that high temperatures and strong sunlight during the rice-growing season can lead to severe water loss in rice plants. Therefore, if the plants respond to harsh temperatures and sunlight at noon by curling their leaves, it can reduce water loss and increase drought resistance. “The ‘noon siesta’ phenomenon or ‘photosynthesis inhibition at noon’ is a mechanism that helps plants adapt and avoid environmental harm,” said Mr. Zhang.
The research team cloned and identified the enzyme encoding the PSL1 gene. The mutation of this gene causes the cell walls in the roots and leaf tissues of rice to thicken, increasing the number of water-retaining cells, which leads to the curling of rice leaves in humid and high-temperature environments.
Biochemical analysis results show that compared to wild plants in desert areas, the galacturonase activity in PSL1 combinations and the pectin content in cells containing the PSL1 mutation increased significantly.
In arid environments, the amount of water sustaining the rice plants is not easily lost. PSL1 plays a role in regulating the cell wall synthesis process, crop development, and drought resistance in rice.
