Vieira Evandro Alves, Gaspar Marilia, Caldeira Cecílio Frois, Munné-Bosch Sergi, Braga Marcia Regina
Vale Institute of Technology, Belém, Brazil.
Biodiversity Conservation Center, Institute of Environmental Research, São Paulo, Brazil.
Front Plant Sci. 2024 Feb 15;15:1344820. doi: 10.3389/fpls.2024.1344820. eCollection 2024.
Desiccation tolerance in vegetative tissues enables resurrection plants to remain quiescent under severe drought and rapidly recover full metabolism once water becomes available. is a resurrection plant that occurs at high altitudes, typically growing on rock slits, exposed to high irradiance and limited water availability. We analyzed the levels of reactive oxygen species (ROS) and antioxidants, carotenoids and its cleavage products, and stress-related phytohormones in fully hydrated, dehydrated, and rehydrated leaves of . This species exhibited a precise adjustment of its antioxidant metabolism to desiccation. Our results indicate that this adjustment is associated with enhanced carotenoid and apocarotenoids, α-tocopherol and compounds of ascorbate-glutathione cycle. While α-carotene and lutein increased in dried-leaves suggesting effective protection of the light-harvesting complexes, the decrease in β-carotene was accompanied of 10.2-fold increase in the content of β-cyclocitral, an apocarotenoid implicated in the regulation of abiotic stresses, compared to hydrated plants. The principal component analysis showed that dehydrated plants at 30 days formed a separate cluster from both hydrated and dehydrated plants for up to 15 days. This regulation might be part of the protective metabolic strategies employed by this resurrection plant to survive water scarcity in its inhospitable habitat.
营养组织中的耐旱性使复苏植物能够在严重干旱下保持静止状态,并在有水时迅速恢复完全的新陈代谢。是一种生长在高海拔地区的复苏植物,通常生长在岩石缝隙中,暴露于高光照和有限的水分条件下。我们分析了该植物完全水合、脱水和再水化叶片中的活性氧(ROS)水平、抗氧化剂、类胡萝卜素及其裂解产物以及与胁迫相关的植物激素。该物种对其抗氧化代谢进行了精确调整以适应脱水。我们的结果表明,这种调整与类胡萝卜素和脱辅基类胡萝卜素、α-生育酚以及抗坏血酸-谷胱甘肽循环的化合物的增加有关。虽然干燥叶片中α-胡萝卜素和叶黄素增加,表明对光捕获复合体有有效保护,但与水合植物相比,β-胡萝卜素的减少伴随着β-环柠檬醛含量增加10.2倍,β-环柠檬醛是一种参与非生物胁迫调节的脱辅基类胡萝卜素。主成分分析表明,30天时的脱水植物与水合植物和长达15天的脱水植物形成了一个单独的聚类。这种调节可能是这种复苏植物在其恶劣栖息地中应对缺水的保护性代谢策略的一部分。