Researchers Find Gene Affecting Alkaline Sensitivity in Plants

Scientists from the Chinese Academy of Sciences have discovered a gene that affects how plants respond to alkaline environments, a finding that could help crop-improvement efforts. Currently, more than 1 billion hectares of land are affected by salt, with around 60 percent deemed sodic soil areas, creating an urgent need for sodic-tolerant crops. But while salinity tolerance has been studied extensively, alkalinity tolerance in plants has not. To fill in this knowledge gap, the researchers performed a genome association analysis of sorghum, a naturally high alkaline-tolerant crop, revealing a major locus called AT1 that is specifically related to alkaline-salinity sensitivity. As reported in Science this week, field trials showed that an AT1 allele with a carboxyl-terminal truncation increased sensitivity, whereas knockout of AT1 increased tolerance to alkalinity in sorghum, millet, rice, and maize. "AT1 encodes an atypical G protein y subunit that affects the phosphorylation of aquaporins to modulate the distribution of hydrogen peroxide," the study's authors write. "These processes appear to protect plants against oxidative stress by alkali." In light of the findings, engineering knockouts of AT1 homologs or selecting its natural nonfunctional alleles could improve crop productivity in saline soils.