文献类型：期刊文献

英文题名：Physiological and Molecular Responses of Poplar to Salt Stress and Salt Tolerance Functional Analysis of Paggrxc9

作者：Wang, Jiechen[1,2,3] Ding, Changjun[3] Cui, Congcong[1,2] Song, Jiaqi[1,2] Ji, Guangxin[1,2] Sun, Nan[1,2] Qi, Siyue[1,2] Li, Jie[1] Xu, Zhiru[1] Zhang, Huihui[1,2]

第一作者：Wang, Jiechen

机构：[1] College of Life Sciences, Northeast Forestry University, Harbin, 150040, China; [2] Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Northeast Forestry University, Harbin, 150040, China; [3] Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Key Lab Tree Breeding & Cultivat, State Forestry Adm, Res Inst Forestry, Beijing, 100091, China

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240264745)

语种：英文

外文关键词：Antioxidants - Forestry - Genes - Photosynthesis - Physiological models - Physiology - Redox reactions - Superoxide dismutase - Yeast

摘要：The exacerbation of soil salinization poses a serious threat to plant survival. In this study, as salt concentration increased (0, 100, 200, and 300 mM NaCl), observable damage to 84K poplar (Populus alba × P. glandulosa) progressively intensified. Under salt stress, differentially expressed genes (DEGs) were primarily enriched in photosynthesis, redox activity, and glutathione metabolism pathways. Salt stress reduced chlorophyll content and net photosynthetic rate, accompanied by the downregulation of photosynthesis-related genes. Treatment with 300 mM NaCl significantly inhibited the photochemical activity of photosystems. The higher photochemical activity under 100 and 200 mM NaCl treatments was attributed to the activated PGR5-CEF photoprotective mechanism. However, the NDH-CEF was inhibited under all salt levels. Salt stress led to the accumulation of reactive oxygen species (ROS), while enhancing the ASA-GSH cycle and activities of antioxidant enzymes like superoxide dismutase to mitigate oxidative damage. Weighted gene co-expression network analysis (WGCNA) using physiological and RNA-seq data identified five photosynthesis-related hub genes (including FNR and TPI) down-regulated by salt stress, and nine antioxidant-related hub genes (including GRX, GPX, and GST) up-regulated by salt stress. GRXC9, encoding glutaredoxin, is likely involved in regulating redox homeostasis under salt stress in a GSH-dependent manner. Functional studies on PagGRXC9 demonstrated that its overexpression significantly enhanced salt tolerance in Saccharomyces cerevisiae. Under salt stress, PagGRXC9-overexpressing poplar exhibited better growth, higher FV/FM and NPQ values in leaves compared to wild-type plants. Additionally, overexpression of PagGRXC9 improved the tolerance of poplar leaves to H2O2-induced oxidative stress. This study constructed the photosynthetic and antioxidant response network for salt stress in poplar, revealing that PagGRXC9 enhances salt tolerance by reducing photoinhibition and increasing antioxidant capacity. These findings provide valuable insights for breeding salt-tolerant forest trees. ? 2024, The Authors. All rights reserved.