Abstract
Elevated carbon dioxide (CO2) generally increases both growth and yield of plants. However, it has been reported in rice that elevated CO2 concomitantly increases leaf temperature via stomatal closure, which has the potential to enhance the high-temperature stress and impede the rice quality. In this study we isolated and characterized the rice mutant deficient in the SLAC1 protein, a stomatal anion channel controlling stomatal opening in response to environmental CO2. The TILLING screening from NMU-mutagenized lines was performed on the rice SLAC1 ortholog gene (OsSLAC1), and several mutations leading to amino acid substitutions were found. Observations of the leaf temperature of homozygous mutant plants using the infrared thermography camera showed that some of them showed constitutive low-temperature phenotypes. These observations indicate that OsSLAC1 is also involved in the stomatal closure in rice and knockdown of OsSLAC1 would be an efficient way to reduce damages caused by increase of leaf temperature at high CO2 environment.
