低温胁迫下水杨酸预处理对茉莉幼苗活性氧及保护酶的影响

【研究目的】为探讨水杨酸(Salicylic acid，SA)预处理对低温胁迫下茉莉(Jasminun Sambac L. Ait)幼苗的影响；【方法】采用叶面喷施不同浓度SA的方法，测定了单、双瓣茉莉经SA预处理后在低温胁迫下存活率、活性氧、保护酶和细胞膜方面的变化。【结果】结果表明，茉莉幼苗经SA预处理后在低温胁迫下存活率有效提高，相对电导率、超氧阴离子(O2-)产生速率、过氧化氢(H2O2)和丙二醛(MDA)含量显著下降，超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性显著提高。最适合提高单、双瓣茉莉耐寒性的SA预处理浓度分别为1.25mmol/L和0.75mmol/L。【结论】这表明SA可通过减轻活性氧积累，提高保护酶活性，保护膜结构和功能，有效缓解低温胁迫对茉莉幼苗的伤害

Effects of SA Pretreatment on Activated Oxygen and Antioxidant Enzyme in Jasmine (Jasminun Sambac) Seedlings under Cold Stress

【OBJECTIVE】To study the effects of SA (Salicylic acid) pretreatment on jasmine (Jasminun Sambac L. Ait) seedlings under cold stress. 【METHOD】SA of different concentrations were sprayed to jasmine leaves and changes of survival percentage, reactive oxygen species, antioxidant enzyme and cell membrane of Single petal jasmine and Double petal jasmine under cold stress were observed. 【RESULTS】Pretreatment with SA, jasmine seedlings’ survival percentage under cold stress was increased effectively, relative conductivity, generating rate of O2-, content of H2O2 and MDA was decreased significantly, furthermore activity of superoxiede dismutase (SOD), peroxidase (POD) and catalse (CAT) was increased significantly. 【CONCLUSION】The best effect concentration of SA pretreatment to enhance cold tolerance of Single petal jasmine and Double petal jasmine was 1.25mmol/L and 0.75mmol/L respectively.