Qingwei Zhang1,2, Shaohu Tang3,4, Jianqiu Li3,4, Chunfen Fan3,4, Libo Xing5, Keming Luo6,7. 1. Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Southwest University, Tiansheng Road No. 2, Beibei, Chongqing, 400715, China. qwzhang18@swu.edu.cn. 2. Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China. qwzhang18@swu.edu.cn. 3. Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Southwest University, Tiansheng Road No. 2, Beibei, Chongqing, 400715, China. 4. Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China. 5. College of Horticulture, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China. 6. Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Southwest University, Tiansheng Road No. 2, Beibei, Chongqing, 400715, China. kemingl@swu.edu.cn. 7. Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, School of Life Sciences, Southwest University, Chongqing, 400715, China. kemingl@swu.edu.cn.
Abstract
MAIN CONCLUSION: The mechanisms underlying long-term complete submergence tolerance in S. variegata involve enhanced oxidative stress responses, strengthened ethylene and ABA signaling, synthesis of raffinose family oligosaccharides, unsaturated fatty acids, and specific stress-related amino acids. Salix variegata Franch. is a riparian shrub species that can tolerate long-term complete submergence; however, the molecular mechanisms underlying this trait remain to be elucidated. In this study, we subjected S. variegata plants to complete submergence for 60 d and collected stems to perform transcriptomic and metabolomic analyses, as well as quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays. Results revealed that photosynthesis and the response to light stimulus were inhibited during submergence and recovered after desubmergence. Ethylene and abscisic acid (ABA) signaling could be important for the long-term submergence tolerance of S. variegata. Jasmonic acid (JA) signaling also participated in the response to submergence. Raffinose family oligosaccharides, highly unsaturated fatty acids, and specific stress-related amino acids accumulated in response to submergence, indicating that they may protect plants from submergence damage, as they do in response to other abiotic stressors. Several organic acids were produced in S. variegata plants after submergence, which may facilitate coping with the toxicity induced by submergence. After long-term submergence, cell wall reorganization and phenylpropanoid metabolic processes (the synthesis of specific phenolics and flavonoids) were activated, which may contribute to long-term S. variegata submergence tolerance; however, the detailed mechanisms require further investigation. Several transcription factors (TFs), such as MYB, continuously responded to submergence, indicating that they may play important roles in the responses and adaption to submergence. Genes related to oxidative stress tolerance were specifically expressed after desubmergence, potentially contributing to recovery of S. variegata plants within a short period of time.
MAIN CONCLUSION: The mechanisms underlying long-term complete submergence tolerance in S. variegata involve enhanced oxidative stress responses, strengthened ethylene and ABA signaling, synthesis of raffinose family oligosaccharides, unsaturated fatty acids, and specific stress-related amino acids. Salix variegata Franch. is a riparian shrub species that can tolerate long-term complete submergence; however, the molecular mechanisms underlying this trait remain to be elucidated. In this study, we subjected S. variegata plants to complete submergence for 60 d and collected stems to perform transcriptomic and metabolomic analyses, as well as quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays. Results revealed that photosynthesis and the response to light stimulus were inhibited during submergence and recovered after desubmergence. Ethylene and abscisic acid (ABA) signaling could be important for the long-term submergence tolerance of S. variegata. Jasmonic acid (JA) signaling also participated in the response to submergence. Raffinose family oligosaccharides, highly unsaturated fatty acids, and specific stress-related amino acids accumulated in response to submergence, indicating that they may protect plants from submergence damage, as they do in response to other abiotic stressors. Several organic acids were produced in S. variegata plants after submergence, which may facilitate coping with the toxicity induced by submergence. After long-term submergence, cell wall reorganization and phenylpropanoid metabolic processes (the synthesis of specific phenolics and flavonoids) were activated, which may contribute to long-term S. variegata submergence tolerance; however, the detailed mechanisms require further investigation. Several transcription factors (TFs), such as MYB, continuously responded to submergence, indicating that they may play important roles in the responses and adaption to submergence. Genes related to oxidative stress tolerance were specifically expressed after desubmergence, potentially contributing to recovery of S. variegata plants within a short period of time.
Entities:
Keywords:
Oxidative stress; Phytohormones; S. variegate; Stress signaling; Submergence tolerance