作者：Jianbo Li 1,2,*, Pei Sun 2,3, Yongxiu Xia 1, Guangshun Zheng 1, Jingshuang Sun 1 and Huixia Jia 2,3,*
单位：1. Experimental Center of Forestry in North China, Chinese Academy of Forestry, Beijing 102300, China; 2. State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China; 3. Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
期刊：International Journal of Molecular Sciences. 2019, 20(22), 5782; doi:10.3390/ijms20225782
基金：National Nonprofit Institute Research Grant of Chinese Academy of Forestry (CAFYBB2019ZY003), the National Natural Science Foundation of China (31800569 and 31800570), China Postdoctoral Science Foundation (2018M631625), and the National Key Program on Transgenic Research (2018ZX08020002).
摘要：The growth and production of poplars are usually affected by unfavorable environmental conditions such as soil salinization. Thus, enhancing salt tolerance of poplars will promote their better adaptation to environmental stresses and improve their biomass production. Stress-associated proteins (SAPs) are a novel class of A20/AN1 zinc finger proteins that have been shown to confer plants’ tolerance to multiple abiotic stresses. However, the precise functions of SAP genes in poplars are still largely unknown. Here, the expression profiles of Populus trichocarpa SAPs in response to salt stress revealed that PtSAP13 with two AN1 domains was up-regulated dramatically during salt treatment. The glucuronidase (GUS) staining showed that PtSAP13 was accumulated dominantly in leaf and root, and the GUS signal was increased under salt condition. The Arabidopsis transgenic plants overexpressing PtSAP13 exhibited higher seed germination and better growth than wild-type (WT) plants under salt stress, demonstrating that overexpression of PtSAP13 increased salt tolerance. Higher activities of antioxidant enzymes were found in PtSAP13-overexpressing plants than in WT plants under salt stress. Transcriptome analysis revealed that some stress-related genes, including Glutathione peroxidase 8, NADP-malic enzyme 2, Response to ABA and Salt 1, WRKYs, Glutathione S-Transferase, and MYBs, were induced by salt in transgenic plants. Moreover, the pathways of flavonoid biosynthesis and metabolic processes, regulation of response to stress, response to ethylene, dioxygenase activity, glucosyltransferase activity, monooxygenase activity, and oxidoreductase activity were specially enriched in transgenic plants under salt condition. Taken together, our results demonstrate that PtSAP13 enhances salt tolerance through up-regulating the expression of stress-related genes and mediating multiple biological pathways.
关键词：stress-associated protein; expression analysis; transgene; salt tolerance; transcriptome; Populus trichocarpa