Project description:Regulation of stomatal movement is one of the effective strategies for developing resistant crops to air pollutant because stomata allows absorption of various air pollutants, such as ozone and sulfur dioxide. Transcription factor (TF) is a fascinating target of genetic manipulation for this end because TF regulates many genes simultaneously and methods of genetic manipulation are universally established. Here, we have screened transgenic Arabidopsis lines expressing chimeric repressor of TFs in high-concentration of ozone and found that the chimeric repressors of GOLDEN-LIKE1 (GLK1) and GLK2 (GLK1-SRDX and GLK2-SRDX) conferred strong tolerance to ozone. These 35S:GLK1/2-SRDX plants also showed sulfur dioxide tolerance. Their leaves showed lower rate of transpiration than wild type and a remarkable closed-stomata phenotype. The expression of the genes encoding K+ and water channels, including KAT1 and AKT1, which are involved in stomatal opening, was downregulated in 35S:GLK1-SRDX plants. Consistently, expression of GLK1-SRDX driven by the GC1 promoter, which has an activity only in guard cell, also induced closed-stomata and an ozone tolerant phenotype. On the contrary, 35S:GLK1/2 plants showed hypersensitivity to ozone and an opened-stomata phenotype. These data suggested that GLK1 and GLK2 have an ability to induce transcriptional change in guard cell and regulate stomatal movement. Our findings provide an effective tool to confer resistance to air pollutant by regulating stomatal aperture and improve crop productivity in future.
