Mesembryanthemum crystallinum (Ice plant) is an annual halophytic plant species spread in the coastal areas of the Mediterranean Sea, Egypt. Information about the behaviour of halophytes under the future concentration of ozone (O₃) is scanty. Therefore, we have assessed the effects of elevated O₃ (ambient + 20 ppb), moderate salinity (200 mM NaCl), and their combined treatment (salinity + elevated O₃) on various morphological, growth, physiological, biochemical and anatomical parameters of Egyptian ice plant. Under salinity stress, plant growth, percentage of pigmented leaf and its thickness, ROS levels, antioxidative enzymes, and ROS scavenging activities were increased, while photosynthetic pigments and efficiency were decreased compared to the control. Elevated O₃ exposure led to reductions in most of the growth parameters and pigments, while ROS levels, histochemical localization of H₂O₂ and ·O₂⁻, antioxidative enzymes and non-enzymatic antioxidants (betacyanin, phenolics, thiols and ascorbic acid) showed increases. Surprisingly, salinity alleviated the oxidative stress of elevated O₃ due to the rise of SOD activity, antioxidant compounds, and a decrease of ·O₂⁻ production rate with concomitant increases of most of the growth parameters. Thick lower collenchyma and enhancement of xylem parenchyma under O₃ and combined treatment suggested that anatomical acclimation also operated under O₃ stress and salinity played a vital role in the growth of this plant under combined stress. Results showed that salt is essential for the optimum development of this species and its role is extended to alleviate the oxidative damage caused by elevated O₃. The results further recommend the use of Egyptian M. crystallinum as a O₃ tolerant crop for saline areas along the Mediterranean Sea coast.

Mesembryanthemum crystallinum（冰植物）是一年生的盐生植物物种，分布在埃及地中海沿岸地区。关于在未来的臭氧（O ₃）浓度下盐生植物行为的信息很少。因此，我们评估了O ₃升高（环境+ 20 ppb），中度盐度（200 mM NaCl）及其联合处理（盐度+ O ₃升高）的影响。），了解埃及冰厂的各种形态，生长，生理，生化和解剖参数。在盐胁迫下，与对照相比，增加了植物的生长，色素叶的百分比及其厚度，ROS水平，抗氧化酶和ROS清除活性，而光合色素和效率却降低了。升高ø ₃曝光导致在大多数生长参数和颜料的减少，而ROS水平中，H组织化学定位₂ ö ₂和·O2 ₂ ^- ，抗氧化酶和非酶抗氧化剂（betacyanin，酚类，硫醇和抗坏血酸）显示增加。出乎意料的是，盐度减轻了升高的O ₃的氧化应激由于SOD活性，抗氧化剂化合物的兴起，和·O2的降低₂ ^-生产速率与大多数生长参数的伴随增加。在O ₃和联合处理下，厚厚的下颈间质和木质部薄壁组织的增强表明，在O ₃胁迫下，解剖适应也起作用，盐度在该复合胁迫下对该植物的生长起着至关重要的作用。结果表明，盐对于该物种的最佳发育必不可少，其作用已扩展到减轻由O ₃升高引起的氧化损伤。结果进一步建议使用埃及结晶毛霉菌作为O ₃ 地中海沿岸盐碱地区的耐性作物。