The marine red algae Gracilaria/Gracilariopsis lemaneiformis were used as materials to study the effects of different concentration of salicylic acid on their growth and stress physiology under high temperature condition. The antioxidant enzyme activity, the osmotic regulation substances, phycobilipro-tein, the features of chlorophyll fluorescence and HSP70 gene were studied when the algae grew in high temperature environment. Results showed that in the salicylic acid treatment group, the growth rate, enzymatic activity or membrane lipids damage degree were better than those of the control group at various degrees, and 5.0 and 10.0 μg/mL of salicylic acid treatment groups were obviously better than the other groups. The treatment with 10.0 ug/mL of salicylic acid showed the best effect with the daily relative growth rate increased 340% compared with the control group. When the treatment was on the 3rd day, each index of the 10.0 ug/mL group reached the maximum value, SOD increased 74%, POD increased 70%, CAT increased 40%, mannitol and proline increased 70% and 26% respectively. The content of phyco-erythrin increased 46.2%, phycocyanin content increased 40%. Compared with the control group, the decrease of MDA content on the first day was the most obvious and decreased nearly 10%. The chlorophyll parameters of Fv/Fm, Fv/Fo, qP and ΦBPS Ⅱ of G. lemaneiformis decreased under high temperature stress, and the variation tendency of NPQ increased first and then declined. It was found that 10.0 ug/mL of salicylic acid could increase the five kinds of chlorophyll fluorescence values compared with the control group. The expression level of HSP70 gene under high temperature was higher than those under normal conditions, while the expression level of high temperature group with salicylic acid treatment was lower than the control group. In conclusion, salicylic acid showed the effect of improving the high temperature resistance of G. lemaneiformis.%以龙须菜为材料,研究了不同浓度水杨酸对高温下龙须菜的生长速率、抗氧化酶、渗透调节物质、藻胆蛋白、叶绿素荧光特性和HSP70基因的影响.结果表明,水杨酸处理组不论是生长、酶活性和膜脂受损情况都不同程度优于对照组,其中5.0、10.0 μg/mL处理组效果较好.10.0 μg/mL水杨酸处理组效果最为明显,日生长速率与对照组相比增长了340％.在处理第3天,10.0 μg/mL处理组各指标达到最大,SOD增长了74％,POD增长了70％,CAT增长了40％.脯氨酸和甘露醇分别增长了70％和26％.藻红蛋白增加了46.2％,藻蓝蛋白增长了40％.与对照组相比,MDA含量第1天下降最为显著,下降了10％.高温胁迫下,龙须菜叶绿素荧光参数Fv/Fm、Fv/Fo、qP和Φ中PSⅡ均明显降低,非光化学淬灭(NPQ)呈现先上升后下降的趋势.水杨酸处理能有效减缓5种龙须菜叶绿素荧光参数的降低程度.水杨酸处理后HSP70基因表达量较对照组低.本实验结果表明水杨酸具有增强龙须菜抗高温胁迫的作用.
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