Acosta-Motos José-Ramón, Diaz-Vivancos Pedro, Álvarez Sara, Fernández-García Nieves, Sanchez-Blanco María Jesús, Hernández José Antonio
Irrigation Department, CEBAS-CSIC, Campus Universitario de Espinardo, P.O. Box 164, 30100, Murcia, Spain.
Planta. 2015 Oct;242(4):829-46. doi: 10.1007/s00425-015-2315-3. Epub 2015 May 15.
We studied the response of Eugenia myrtifolia L. plants, an ornamental shrub native to tropical and subtropical areas, to salt stress in order to facilitate the use of these plants in Mediterranean areas for landscaping. E. myrtifolia plants implement a series of adaptations to acclimate to salinity, including morphological, physiological and biochemical changes. Furthermore, the post-recovery period seems to be detected by Eugenia plants as a new stress situation. Different physiological and biochemical changes in Eugenia myrtifolia L. plants after being subjected to NaCl stress for up to 30 days (Phase I) and after recovery from salinity (Phase II) were studied. Eugenia plants proved to be tolerant to NaCl concentrations between 44 and 88 mM, displaying a series of adaptative mechanisms to cope with salt-stress, including the accumulation of toxic ions in roots. Plants increased their root/shoot ratio and decreased their leaf area, leaf water potential and stomatal conductance in order to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including the limited accumulation of toxic ions in leaves, increase in chlorophyll content, changes in chlorophyll fluorescence parameters, leaf anatomy and antioxidant defence mechanisms. Anatomical modifications in leaves, including an increase in palisade parenchyma and intercellular spaces and decrease in spongy parenchyma, served to facilitate CO2 diffusion in a situation of reduced stomatal aperture. Salinity produced oxidative stress in Eugenia plants as evidenced by oxidative stress parameters values and a reduction in APX and ASC levels. Nevertheless, SOD and GSH contents increased. The post-recovery period is detected as a new stress situation, as observed through effects on plant growth and alterations in chlorophyll fluorescence and oxidative stress parameters.
我们研究了原产于热带和亚热带地区的观赏灌木番樱桃（Eugenia myrtifolia L.）植株对盐胁迫的响应，以便于这些植物在地中海地区用于景观美化。番樱桃植株会进行一系列适应性变化以适应盐度，包括形态、生理和生化变化。此外，番樱桃植株似乎将恢复期视为一种新的胁迫状况。我们研究了番樱桃（Eugenia myrtifolia L.）植株在经受长达30天的NaCl胁迫（第一阶段）以及从盐胁迫中恢复后（第二阶段）不同的生理和生化变化。结果表明，番樱桃植株能够耐受44至88 mM的NaCl浓度，展现出一系列应对盐胁迫的适应机制，包括在根部积累有毒离子。植株增加根冠比，减小叶面积、叶片水势和气孔导度以限制水分流失。此外，它们还展现出不同的策略来保护光合机制，包括限制叶片中有毒离子的积累、增加叶绿素含量、改变叶绿素荧光参数、叶片解剖结构以及抗氧化防御机制。叶片的解剖结构变化，包括栅栏薄壁组织和细胞间隙增加以及海绵薄壁组织减少，有助于在气孔孔径减小的情况下促进二氧化碳扩散。盐胁迫在番樱桃植株中产生了氧化应激，这可通过氧化应激参数值以及抗坏血酸过氧化物酶（APX）和抗坏血酸（ASC）水平的降低得到证明。然而，超氧化物歧化酶（SOD）和谷胱甘肽（GSH）含量增加。正如通过对植物生长的影响以及叶绿素荧光和氧化应激参数的变化所观察到的，恢复期被视为一种新的胁迫状况。
