Luhua Li1,2, Dingli Hong1,2, Chang An1,2, Yuxuan Chen1,2, Pengpeng Zhao1,2, Xin Li1,2, Fumin Xiong1,2, Mingjian Ren1,2, Ruhong Xu3,4. 1. College of Agriculture, Guizhou University, Guiyang, 550025, China. 2. Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China. 3. College of Agriculture, Guizhou University, Guiyang, 550025, China. xrhgz@163.com. 4. Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China. xrhgz@163.com.
Abstract
BACKGROUND: Stomata, which play important roles in both optimizing photosynthesis efficiency and adapting to stress, are closely related to IAA and ABA. In plants, the auxin influx carrier LAX3 has been found to play roles in development and stress tolerance. However, the function of LAX3 in stomata and in response to salt stress remains largely unknown. METHODS AND RESULTS: Here, we show that overexpression of wheat TaLAX3-1B in tobacco results in a decrease in stomatal aperture and a relatively closed state of the stomata. In addition, the stomatal movement of the OxTaLAX3-1B lines was less sensitive to ABA than that of the WT. Consistently, compared with the WT, the OxTaLAX3-1B lines showed significantly higher expression of stomate-, IAA- and ABA-related genes and endogenous IAA and ABA contents. Furthermore, compared with the WT, the OxTaLAX3-1B lines exhibited higher proline content, salt stress-related gene expression and ROS antioxidant enzyme activity but lower MDA content and ROS accumulation after salt treatment. CONCLUSIONS: The present results suggest that TaLAX3-1B plays a positive role in regulating stomatal closure and enhancing salt stress tolerance.
BACKGROUND: Stomata, which play important roles in both optimizing photosynthesis efficiency and adapting to stress, are closely related to IAA and ABA. In plants, the auxin influx carrier LAX3 has been found to play roles in development and stress tolerance. However, the function of LAX3 in stomata and in response to salt stress remains largely unknown. METHODS AND RESULTS: Here, we show that overexpression of wheat TaLAX3-1B in tobacco results in a decrease in stomatal aperture and a relatively closed state of the stomata. In addition, the stomatal movement of the OxTaLAX3-1B lines was less sensitive to ABA than that of the WT. Consistently, compared with the WT, the OxTaLAX3-1B lines showed significantly higher expression of stomate-, IAA- and ABA-related genes and endogenous IAA and ABA contents. Furthermore, compared with the WT, the OxTaLAX3-1B lines exhibited higher proline content, salt stress-related gene expression and ROS antioxidant enzyme activity but lower MDA content and ROS accumulation after salt treatment. CONCLUSIONS: The present results suggest that TaLAX3-1B plays a positive role in regulating stomatal closure and enhancing salt stress tolerance.
Authors: Mohammad Salehin; Baohua Li; Michelle Tang; Ella Katz; Liang Song; Joseph R Ecker; Daniel J Kliebenstein; Mark Estelle Journal: Nat Commun Date: 2019-09-06 Impact factor: 14.919