Effects of drought hardening on the carbohydrate dynamics of Quercus acutissima seedlings under successional drought

Frontiers in Plant Science

Plant Science

Mingming Zhao¹  Xinke Sun¹  Xiao Liu²  Hui Wang²  Renqing Wang²  Ning Wang²  Ning Du³  Lele Liu³  Qiang Li⁴  Peixian Fan⁵  Qun Gao⁵ 

[1] Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China;Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China;Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China;Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China;Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China;Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China;Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China;Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China;Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China;School of Tropical Medicine, Hainan Medical University, Haikou, China;Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China;Qingdao Key Laboratory of Forest and Wetland Ecology, Shandong University, Qingdao, China;

关键词: carbon allocation;    drought-trained;    phenotypic plasticity;    Quercus acutissima;    stress memory;    water fluctuations;   

DOI  :  10.3389/fpls.2023.1184584

 received in 2023-03-12, accepted in 2023-08-09,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionAs precipitation patterns are predicted to become increasingly erratic, the functional maintenance of warm-temperate forests constitutes a key challenge for forest managers. In this study, 2-year-old Quercus acutissima seedlings were selected to elucidate the mechanisms whereby they respond to soil water fluctuations and the drought hardening effects on plant carbohydrate dynamics.MethodsSeedlings were trained under different soil water conditions for 2 months: drought (D), well-watered (W), 1-month drought and then 1-month well-watered (D-W), and 1-month well-watered and then 1-month drought (W-D). The functional traits involved in water- and carbon-use strategies were explored at the end of the hardening period. Compared with seedlings in group W, seedlings in groups D, D-W, and W-D had increased potential for carbon uptake (i.e., light saturated point, maximum ribulose-1,5-bisphosphate (RuBP) saturated rate, and electron transport rate) and water uptake (i.e., fine root–to–coarse root ratio) and downregulated growth and mitochondrial respiration to decrease carbon consumption. After water fluctuation hardening, we performed a successional dry-down experiment for 1 month to detect carbohydrate dynamics and explore the acclimation caused by prior hardening.Results and discussionOur results revealed that there were more soluble sugars allocated in the leaves and more starch allocated in the stems and roots of seedlings hardened in the D, W-D, and D-W treatments than that of seedlings hardened in the W treatment. No significant changes in total non-structural carbohydrates were found. In addition, we found near-zero (seedlings trained by D and D-W treatments) or negative (seedlings trained by W-D treatment) growth of structural biomass at the end of the dry-down experiment, which was significantly lower than that of W-hardened seedlings. This suggests that there was a shift in allocation patterns between carbon storage and growth under recurrent soil drought, which can be strengthened by drought memory. We conclude that Q. acutissima seedlings adjusted water- and carbon-use strategies in response to water fluctuations, whereas stress memory can enhance their overall performance in reoccurring drought. Therefore, taking advantage of stress memory is a promising management strategy in forest nurseries, and drought-trained seedlings might be more suitable for afforestation practices in sites characterized by fluctuating soil water content, considering the ongoing global climatic changes.

【 授权许可】

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Copyright © 2023 Li, Liu, Sun, Zhao, Liu, Wang, Gao, Fan, Du, Wang and Wang