Purslane (Portulaca oleracea L.) is a plant with a long history in cooking and folk medicine that has been distributed worldwide. In the present study, purslane was used as a model plant to investigate the effect of foliar application of salicylic acid (SA) on plant tolerance to drought stress. The effects of SA foliar spray (0, 0.5 and 1 mM) on physiological and biochemical responses of purslane seedlings under drought stress (90, 60 and 30% field capacity) were investigated. The results showed that drought stress decreased the contents of photosynthetic pigments, parameters of gas exchanges, proline, soluble sugars, total phenolic, flavonoids, growth, and biomass production. However, SA improved photosynthetic pigments, gas exchanges, compatible solutes and secondary metabolites and thereby increased purslane growth and biomass production. Drought stress also induced oxidative stress (H₂O₂ and MDA) in purslane seedlings; however, SA reduced the drought-induced oxidative stress by regulating the activity of antioxidant enzymes. Drought stress increased the content of palmitic and arachidonic acid and decreased unsaturated fatty acids (oleic, linoleic and linolenic acid), stearic and behenic acid in the leaves of purslane. However, SA improved the fatty acids content under drought stress. These results indicate that foliar application of SA improved the adaptation and tolerance of the purslane plant to drought stress by improving gas exchange, increasing the accumulation of secondary metabolites and compatible solutes, improving the antioxidant defence system and regulating the fatty acids profile of membrane lipid.

马齿（（马齿ulaL.）是一种在烹饪和民间医学领域拥有悠久历史的植物，已在全球范围内分发。在本研究中，马齿ane被用作模型植物，以研究叶面施用水杨酸（SA）对植物抗旱性的影响。研究了SA叶面喷洒（0、0.5和1 mM）对干旱胁迫（90％，60％和30％的田间持水量）马齿sl幼苗生理和生化响应的影响。结果表明，干旱胁迫降低了光合色素的含量，气体交换参数，脯氨酸，可溶性糖，总酚，类黄酮，生长和生物量的产生。但是，SA改善了光合色素，气体交换，相容性溶质和次生代谢产物，从而提高了马齿sl的生长和生物量的生产。_马齿ane幼苗中的₂ O ₂和MDA）；但是，SA通过调节抗氧化酶的活性来减轻干旱引起的氧化应激。干旱胁迫增加了马齿sl叶片中棕榈酸和花生四烯酸的含量，减少了不饱和脂肪酸（油酸，亚油酸和亚麻酸），硬脂酸和山hen酸的含量。然而，SA改善了干旱胁迫下的脂肪酸含量。这些结果表明，叶面施用SA通过改善气体交换，增加次生代谢产物和相容性溶质的积累，改善抗氧化防御系统并调节膜脂的脂肪酸谱，改善了马齿sl植物对干旱胁迫的适应性和耐受性。