摘要
Plants absorb sunlight to power the photochem- ical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mech- anism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice （Oryza sativa L.） SLAC7 is a generally expressed membrane protein. Loss- of-function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf damage such as H^O2 and abscisic acid levels were significantly higher in slac7-1 than in the wild type. Consistently, the photosynthesis efficiency and Fv/Fm ratio of slac7-1 were significantly decreased （similar to photoinhibition）. In response to chloroplast damage, slat7- 1 altered its leaf morphology （curled or fused leaf） by the synergy between plant hormones and transcriptional factors to decrease the absorption of light, suggesting that a photoprotection mechanism for chloroplast damage was activated in slac7-1. When grown in dark conditions, slac7-1 displayed a normal phenotype. 5LAC7 under the control of the AtSLAC1 promoter could partially complement thephenotypes of Arabidopsis slacl mutants, indicating a partial conservation of SLAC protein functions. These results suggest that SLAC7 is essential for maintaining the chloroplast stability in rice.
Plants absorb sunlight to power the photochem- ical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mech- anism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice （Oryza sativa L.） SLAC7 is a generally expressed membrane protein. Loss- of-function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf damage such as H^O2 and abscisic acid levels were significantly higher in slac7-1 than in the wild type. Consistently, the photosynthesis efficiency and Fv/Fm ratio of slac7-1 were significantly decreased （similar to photoinhibition）. In response to chloroplast damage, slat7- 1 altered its leaf morphology （curled or fused leaf） by the synergy between plant hormones and transcriptional factors to decrease the absorption of light, suggesting that a photoprotection mechanism for chloroplast damage was activated in slac7-1. When grown in dark conditions, slac7-1 displayed a normal phenotype. 5LAC7 under the control of the AtSLAC1 promoter could partially complement thephenotypes of Arabidopsis slacl mutants, indicating a partial conservation of SLAC protein functions. These results suggest that SLAC7 is essential for maintaining the chloroplast stability in rice.
基金
funded by the National High Technology Research and Development Program of China (863 Program)
the National Program of Transgenic Variety Development of China
the National Natural Science Foundation of China
