Gul Bilquees, Manzoor Sumaira, Rasheed Aysha, Hameed Abdul, Ahmed Muhammad Zaheer, Koyro Hans-Werner
Dr. Muhammad Ajmal Khan Institute of Sustainable Halophyte Utilization, University of Karachi, Karachi 75270, Pakistan.
Department of Botany, Government Degree D.J. Science College, Karachi 74400, Pakistan.
Plants (Basel). 2024 Nov 28;13(23):3332. doi: 10.3390/plants13233332.
(Decne.) is a leaf succulent C perennial found in arid saline areas of southern Pakistan and neighboring countries, where it is utilized as herbal medicine. This study investigated how growth, water relations, ion content, chlorophyll fluorescence, and antioxidant system of change as salinity levels increase (0, 150, 300, 600, and 900 mM NaCl). Salinity increments inhibited total plant fresh weight, whereas dry weight remained constant at moderate salinity and decreased at high salinity. Leaf area, succulence, and relative water content decreased as salinity increased. Similarly, the sap osmotic potential of both roots and shoots declined as NaCl concentrations increased. Except for a transitory increase in roots at 300 mM NaCl, sodium concentrations in roots and shoots increased constitutively to more than five times higher under saline conditions than in non-saline controls. Root potassium increased briefly at 300 mM NaCl but did not respond to NaCl treatments in the leaf. Photosynthetic pigments increased with 300 and 600 mM NaCl compared to non-saline treatments, although carotenoids appeared unaffected by NaCl treatments. Except for very high NaCl concentration (900 mM), salinity showed no significant effect on the maximum efficiency of photosystem II photochemistry (Fv/Fm). Light response curves demonstrated reduced absolute (ETR) and maximum electron transport rates (ETR) for the 600 and 900 mM NaCl treatments. The alpha (α), which indicates the maximum yield of photosynthesis, decreased with increasing NaCl concentrations, reaching its lowest at 900 mM NaCl. Non-photochemical quenching (NPQ) values were significantly higher under 150 and 300 mM NaCl treatments than under non-saline and higher NaCl treatments. Electrolyte leakage, malondialdehyde (MDA), and hydrogen peroxide (HO) peaked only at 900 mM NaCl. Superoxide dismutase and glutathione reductase activities and glutathione content in both roots and shoots increased progressively with increasing salinity. Hence, growth reduction under low to moderate (150-600 mM NaCl) salinity appeared to be an induced response, while high (900 mM NaCl) salinity was injurious.
（Decne.）是一种多年生肉质叶植物，生长于巴基斯坦南部及周边国家的干旱盐碱地区，在当地被用作草药。本研究调查了随着盐度水平升高（0、150、300、600和900 mM NaCl），其生长、水分关系、离子含量、叶绿素荧光和抗氧化系统如何变化。盐度增加抑制了植株总鲜重，而干重在中度盐度下保持恒定，在高盐度下降低。随着盐度增加，叶面积、肉质化程度和相对含水量下降。同样，随着NaCl浓度增加，根和地上部的汁液渗透势下降。除了在300 mM NaCl时根中出现短暂增加外，在盐胁迫条件下，根和地上部的钠浓度持续增加，比非盐胁迫对照高出五倍以上。根中的钾在300 mM NaCl时短暂增加，但在叶中对NaCl处理无反应。与非盐处理相比，300和600 mM NaCl处理下光合色素增加，尽管类胡萝卜素似乎不受NaCl处理影响。除了非常高的NaCl浓度（900 mM）外，盐度对光系统II光化学的最大效率（Fv/Fm）没有显著影响。光响应曲线表明，600和900 mM NaCl处理下的绝对电子传递速率（ETR）和最大电子传递速率降低。表示光合作用最大产量的α随着NaCl浓度增加而降低，在900 mM NaCl时达到最低。非光化学猝灭（NPQ）值在150和300 mM NaCl处理下显著高于非盐处理和更高NaCl处理。电解质渗漏、丙二醛（MDA）和过氧化氢（HO）仅在900 mM NaCl时达到峰值。根和地上部的超氧化物歧化酶和谷胱甘肽还原酶活性以及谷胱甘肽含量随着盐度增加而逐渐增加。因此，低至中度（150 - 600 mM NaCl）盐度下生长减少似乎是一种诱导反应，而高（900 mM NaCl）盐度则具有伤害性。
