Stomatal movements regulate gas exchange, thus directly affecting the efficiency of photosynthesis and the sensitivity of plants to air pollutants such as ozone. The GARP family transcription factors GOLDEN 2-LIKE1 (GLK1) and GLK2 have known functions in chloroplast development. Here, we show that Arabidopsis thaliana (A. thaliana) plants expressing the chimeric repressors for GLK1 and-2 (GLK1/2-SRDX) exhibited a closed-stomata phenotype and strong tolerance to ozone. By contrast, plants that overexpress GLK1/2 exhibited an open-stomata phenotype and higher sensitivity to ozone. The plants expressing GLK1-SRDX had reduced expression of the genes for inwardly rectifying K+ (K+ in) channels and reduced K+ in channel activity. Abscisic acid treatment did not affect the stomatal phenotype of 35S:GLK1/2-SRDX plants or the transcriptional activity for K+ in channel gene, indicating that GLK1/2 act independently of abscisic acid signaling. Our results indicate that GLK1/2 positively regulate the expression of genes for K+ in channels and promote stomatal opening. Because the chimeric GLK1-SRDX repressor driven by a guard cell-specific promoter induced a closed-stomata phenotype without affecting chloroplast development in mesophyll cells, modulating GLK1/2 activity may provide an effective tool to control stomatal movements and thus to confer resistance to air pollutants.
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - Apr 12 2016|
- K channel
- Stomatal movement
- Transcription factor
ASJC Scopus subject areas