Hubei International Scientific and Technological Center of Ecological Conservation and Management in the Three Gorges Area, Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, Hubei, 443002, PR China.
Hubei International Scientific and Technological Center of Ecological Conservation and Management in the Three Gorges Area, Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, Hubei, 443002, PR China.
Plant Physiol Biochem. 2020 Dec;157:1-12. doi: 10.1016/j.plaphy.2020.10.006. Epub 2020 Oct 13.
Submergence tolerance is crucial when thinking in promising species for restoration of ecosystems prone to suffer extreme flooding events. In this study, two-year-old seedlings of Distylium chinense were subjected to one field study and five controlled experiments: unsubmerged and watered daily as controls (CK) and completely submerged for 30, 60, 90 and 120 days, respectively followed by a 60-day recovery period to test the submergence tolerance. The results showed that the survival decreased with the increasing flooding duration. Different submergence duration treatments affected dry mass accumulation and carbohydrate content of roots, stems and leaves. Flooding stress affected the activities of pyruvate decarboxylase (PDC), ethanol dehydrogenase (ADH) and lactic dehydrogenase (LDH) enzymes, which indicated the roots and leaves adapt to long-term flooding by reinforcing their anaerobic respiration and activities of ADH were higher than those of LDH for roots and leaves with stronger alcoholic fermentation mainly. After de-submergence, the recovery patterns of carbohydrate were coincided with those of dry mass accumulation of the roots, stems and leaves. A significant regression equation analysis showed root starch content and dry mass accumulation were the major factors affecting the seedling survival. And D. chinense accumulated substantial amounts of carbohydrate before submergence and invested more in roots and stems than in leaves, which enhances long-term survival under submergence. Carbohydrate storage is a key functional trait that can explain high survival under submergence. D. chinense may have adopted a suite of growth and respiratory metabolic adaptation strategies to survive long-term submergence.
在思考有潜力用于恢复易受极端洪水事件影响的生态系统的物种时，耐淹水能力至关重要。在这项研究中，对两年生的中华蚊母树苗进行了一项田间研究和五项控制实验：未淹没且每天浇水作为对照（CK），以及分别完全淹没 30、60、90 和 120 天，随后进行 60 天恢复期，以测试耐淹水能力。结果表明，存活率随淹水时间的增加而降低。不同的淹水持续时间处理影响了根、茎和叶的干物质积累和碳水化合物含量。水淹胁迫影响了丙酮酸脱羧酶（PDC）、乙醇脱氢酶（ADH）和乳酸脱氢酶（LDH）酶的活性，这表明根和叶通过加强其无氧呼吸来适应长期水淹，并且根和叶中的 ADH 活性高于 LDH，主要进行更强的酒精发酵。去淹没后，碳水化合物的恢复模式与根、茎和叶的干物质积累模式相吻合。显著的回归方程分析表明，根淀粉含量和干物质积累是影响幼苗存活率的主要因素。中华蚊母在淹没前积累了大量碳水化合物，并在根和茎中投入更多，而在叶中投入较少，这增强了在淹没下的长期生存能力。碳水化合物储存是一个关键的功能特征，可以解释在淹没下的高存活率。中华蚊母可能采用了一系列生长和呼吸代谢适应策略来在长期淹没下生存。
