College of Soil and Water Conservation, Beijing Forestry University, Beijing, 100083, China.
Engineering Research Center of Forestry Ecological Engineering of Ministry of Education, Beijing Forestry University, Beijing, 100083, China.
Sci Rep. 2024 Oct 23;14(1):25078. doi: 10.1038/s41598-024-76455-1.
This study aimed to investigate the adaptive mechanisms of mulberry (Morus alba) to waterlogged conditions, with a specific focus on the development of adventitious roots (ARs), alteration of growth strategies, and adjustment of chlorophyll fluorescence parameters. To achieve this goal, 4-year-old potted mulberry plants were selected for research, and a waterlogging simulation method was implemented. Four treatments were established to investigate the effects of varying water conditions on leaf waterlogging damage, the number of ARs, plant height, chlorophyll fluorescence parameters, and proton motive force (pmf) parameters in mulberry plants. These treatments included the control group (CK), shallow submerged group (SS), half-submerged group (HS) and deep submerged group (DS). Our results showed that (1) The number of ARs in each group increased with increasing waterlogging time. (2) Waterlogging stress inhibited the height growth of mulberry, and the changes in plant height in the HS and DS groups were significantly lower than those in the CK and SS groups. (3) The maximum photochemical quantum yield (Fv/Fm) in the HS and DS groups decreased significantly under waterlogging stress. The nonphotochemical quenching (NPQ) of mulberry leaves in the submergence group increased significantly in the early stage of waterlogging stress, and the NPQ in the submergence group increased continuously with increasing waterlogging time. (4) Thylakoid conductivity to protons (g) in the leaves of mulberry decreased significantly under waterlogging stress, whereas the steady-state rate of proton flux (v) and total electrochromic shift (ECS) increased significantly. The morphological, physiological, and ecological responses of mulberry plants to waterlogging stress include the timely generation of ARs at the stem base, the adjustment of plant growth strategies, and the repair of photosynthetic response centers in leaves through heat dissipation and thylakoid acidification mechanisms.
本研究旨在探讨桑树（Morus alba）适应水淹条件的适应机制，特别关注不定根（ARs）的发育、生长策略的改变以及叶绿素荧光参数的调整。为实现这一目标，选择了 4 年生盆栽桑树进行研究，并采用了水淹模拟方法。设立了四个处理组，以研究不同水条件对桑叶水淹损伤、不定根数量、株高、叶绿素荧光参数和质子动力势（pmf）参数的影响。这些处理包括对照组（CK）、浅浸没组（SS）、半浸没组（HS）和深浸没组（DS）。我们的结果表明：（1）每个组的不定根数量随水淹时间的增加而增加。（2）水淹胁迫抑制了桑树的高度生长，HS 和 DS 组的株高变化明显低于 CK 和 SS 组。（3）HS 和 DS 组在水淹胁迫下最大光化学量子产量（Fv/Fm）显著降低。水淹胁迫下，桑树叶片的非光化学猝灭（NPQ）在早期显著增加，淹没组的 NPQ随水淹时间的增加而持续增加。（4）水淹胁迫下，桑叶类囊体对质子的导度（g）显著降低，而质子流的稳态速率（v）和总电致变色位移（ECS）显著增加。桑树植物对水淹胁迫的形态、生理和生态响应包括及时在茎基部产生不定根、调整植物生长策略以及通过热耗散和类囊体酸化机制修复叶片中的光合反应中心。
