Najar Basma, Pistelli Laura, Marchioni Ilaria, Pistelli Luisa, Muscatello Beatrice, De Leo Marinella, Scartazza Andrea
Department of Pharmacy, University of Pisa, 56124 Pisa, Italy.
Department of Agriculture, Food and Environment (DAFE), University of Pisa, 56124 Pisa, Italy.
Plants (Basel). 2020 Dec 18;9(12):1797. doi: 10.3390/plants9121797.
The present study aimed to elucidate the salinity influence on the bioactive metabolites of L. (henna) plants. Young henna plants were cultivated under salinity stress with two NaCl concentrations (75 mM and 150 mM) in controlled environmental conditions and the leaves were investigated to check their adaptative responses. The modulation of photosynthetic performance to salinity stress was demonstrated by gas exchange and chlorophyll fluorescence parameters. The partial stomatal closure triggered an enhanced water-use efficiency, and a proline accumulation was observed, leading to an osmotic adjustment. The increased capacity to dissipate the excess excitation energy at photosystem II as heat was associated with changes in chlorophylls, anthocyanins, and carotenoids. The higher antioxidant activity at 150 mM salt level suggested its scavenger role on reactive oxygen species (ROS) dissipation and photoprotection. The reduced CO uptake and the higher metabolic costs necessary to sustain the henna tolerance mechanism against high NaCl concentration negatively affected lawsone production. Leaf volatile organic compounds (VOCs) showed changes in the amount and composition of VOCs with increasing salinity level. Overall, this study revealed efficient physiological and biochemical adaptations of henna leaves to salt stress despite an altered production of important economic metabolites such as lawsone.
本研究旨在阐明盐度对散沫花植物生物活性代谢产物的影响。在可控环境条件下，将年轻的散沫花植物置于两种NaCl浓度（75 mM和150 mM）的盐胁迫下进行培养，并对叶片进行研究以检查其适应性反应。通过气体交换和叶绿素荧光参数证明了光合性能对盐胁迫的调节作用。部分气孔关闭引发了水分利用效率的提高，并观察到脯氨酸积累，从而导致渗透调节。光合系统II将多余激发能以热的形式耗散的能力增强，这与叶绿素、花青素和类胡萝卜素的变化有关。在150 mM盐水平下较高的抗氧化活性表明其在活性氧（ROS）清除和光保护方面的作用。CO吸收减少以及维持散沫花对高NaCl浓度的耐受机制所需的更高代谢成本对指甲花醌的产生产生了负面影响。叶片挥发性有机化合物（VOCs）的数量和组成随盐度水平的增加而发生变化。总体而言，本研究表明，尽管重要经济代谢产物如指甲花醌的产量发生了变化，但散沫花叶片对盐胁迫具有有效的生理和生化适应性。
