Fu Pei-Li, Zhang Ya, Zhang Yong-Jiang, Finnegan Patrick M, Yang Shi-Jian, Fan Ze-Xin
CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China.
AoB Plants. 2022 Jul 31;14(4):plac033. doi: 10.1093/aobpla/plac033. eCollection 2022 Aug.
Desiccation-tolerant (DT) plants can withstand dehydration to less than 0.1 g HO g dry weight. The mechanism for whole-plant recovery from severe dehydration is still not clear, especially for woody DT plants. In the present study, we evaluated the desiccation tolerance and mechanism of recovery for a potentially new woody resurrection plant (Gesneriaceae). We monitored the leaf water status, leaf gas exchange, chlorophyll fluorescence and root pressure of potted during dehydration and rehydration, and we investigated the water content and chlorophyll fluorescence of leaves in the field during the dry season. After re-watering from a severely dehydrated state, leaf maximum quantum yield of photosystem II of quickly recovered to well-watered levels. Leaf water status and leaf hydraulic conductance quickly recovered to well-watered levels after re-watering, while leaf gas exchange traits also trended to recovery, but at a slower rate. The maximum root pressure in rehydrated was more than twice in well-watered plants. Our study identified as a new DT woody plant. The whole-plant recovery of from extreme dehydration is potentially associated with an increase of root pressure after rehydration. These findings provide insights into the mechanisms of recovery of DT plants from dehydration.
耐旱（DT）植物能够承受脱水至干重含水量低于0.1克水/克干重。植株从严重脱水状态恢复的机制仍不清楚，尤其是对于木本DT植物而言。在本研究中，我们评估了一种潜在的新型木本复苏植物（苦苣苔科）的耐旱性及恢复机制。我们监测了盆栽植株在脱水和复水过程中的叶片水分状况、叶片气体交换、叶绿素荧光和根压，并调查了旱季田间叶片的含水量和叶绿素荧光。从严重脱水状态重新浇水后，该植物光合系统II的叶片最大量子产量迅速恢复到水分充足时的水平。重新浇水后，叶片水分状况和叶片水力导度迅速恢复到水分充足时的水平，而叶片气体交换特征也趋于恢复，但速度较慢。复水后该植物的最大根压是水分充足植株的两倍多。我们的研究确定该植物为一种新的DT木本植物。该植物从极端脱水状态的整体恢复可能与复水后根压的增加有关。这些发现为DT植物从脱水状态恢复的机制提供了见解。
