Jinhui Zhao1,2,3, Wei Zhang2, Jaime A Teixeira da Silva4, Xuncheng Liu5,6, Jun Duan7. 1. College of Life Sciences and Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang Normal University, Xinyang, 464000, China. 2. South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. 3. National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China. 4. Independent, P. O. Box 7, Miki-cho Post Office, Ikenobe 3011-2, Kagawa-ken, 761-0799, Japan. 5. South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. xunchengliu@scbg.ac.cn. 6. Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China. xunchengliu@scbg.ac.cn. 7. South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. duanj@scbg.ac.cn.
Abstract
MAIN CONCLUSION: HDA704 enhances drought and salt tolerance via stomata-regulated mechanism. HDA704 negatively regulates stomatal aperture and density, repressing the transcription of DST and ABIL2 by histone deacetylation modification. Drought and salinity can damage crop growth and reduce yield. Stomata play an important role in abiotic stress tolerance. In this study on rice, we identified the RPD3/HDA1-type histone deacetylase HDA704 as a positive regulatory factor in drought and salt tolerance. HDA704 was induced by drought and salt stresses. Overexpression of HDA704 in transgenic rice promoted stomatal closure, decreased the number of stomata and slowed down the rate of water loss, consequently resulting in increased drought and salt tolerance. By contrast, knockdown of HDA704 in transgenic rice decreased stomatal closure and accelerated the rate of water loss, leading to decrease drought and salt tolerance. We detected the transcript expression of DST (Drought and Salt Tolerance) and ABIL2 (Abscisic Acid-insensitive Like2), which positively regulate stomatal aperture and density in rice. Our results showed that HDA704 directly binds to DST and ABIL2, repressing their expression via histone deacetylation modification. Collectively, these findings reveal that HDA704 positively regulates drought and salt tolerance by repressing the expression of DST and ABIL2. Our findings provide a new insight into the molecular mechanisms of stomata-regulated abiotic stress tolerance of plants.
MAIN CONCLUSION: HDA704 enhances drought and salt tolerance via stomata-regulated mechanism. HDA704 negatively regulates stomatal aperture and density, repressing the transcription of DST and ABIL2 by histone deacetylation modification. Drought and salinity can damage crop growth and reduce yield. Stomata play an important role in abiotic stress tolerance. In this study on rice, we identified the RPD3/HDA1-type histone deacetylase HDA704 as a positive regulatory factor in drought and salt tolerance. HDA704 was induced by drought and salt stresses. Overexpression of HDA704 in transgenic rice promoted stomatal closure, decreased the number of stomata and slowed down the rate of water loss, consequently resulting in increased drought and salt tolerance. By contrast, knockdown of HDA704 in transgenic rice decreased stomatal closure and accelerated the rate of water loss, leading to decrease drought and salt tolerance. We detected the transcript expression of DST (Drought and Salt Tolerance) and ABIL2 (Abscisic Acid-insensitive Like2), which positively regulate stomatal aperture and density in rice. Our results showed that HDA704 directly binds to DST and ABIL2, repressing their expression via histone deacetylation modification. Collectively, these findings reveal that HDA704 positively regulates drought and salt tolerance by repressing the expression of DST and ABIL2. Our findings provide a new insight into the molecular mechanisms of stomata-regulated abiotic stress tolerance of plants.