水杨酸对高温胁迫下铁皮石斛幼苗耐热性的影响

为研究不同浓度水杨酸对铁皮石斛幼苗耐热性的诱导效应,以移栽半年的铁皮石斛幼苗为实验材料,对不同浓度水杨酸诱导高温胁迫下铁皮石斛幼苗的耐热性进行外观评价及叶绿素、可溶性蛋白质、可溶性糖、丙二醛(MDA)、游离脯氨酸(Pro)含量以及超氧化物歧化酶(SOD)、过氧化酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性的动态测定,观察其动态变化趋势并筛选最佳施用浓度.结果显示:在高温胁迫环境下,随着胁迫时间的延长,不同浓度SA处理均能有效缓解高温对铁皮石斛植株伤害；1.5～2.0 mmol·L1SA处理使铁皮石斛叶片中SOD、POD活性显著提高,0.5～1.5 mmol·L-1 SA处理叶片中CAT、APX活性显著提高；1.5～2.0 mmol·L-1SA处理可显著促进叶片Pro、可溶性糖和可溶性蛋白的积累,有效抑制MDA含量的增加,且不同浓度处理之间差异显著.研究表明,适宜浓度水杨酸处理能提高铁皮石斛幼苗的耐热性,并以1.5 mmol·L-1浓度处理效果最好.

Effects of Salicylic Acid on Heat-resistance of Dendrobium officinale Seedling under High Temperature Stress

To study the effects of different concentrations of salicylic acid on the heat resistance,we used Dendrobium officinale Kimura et Migo seedlings which is transplanted six months for the experimental material,observed and evaluated its heat tolerance under high temperature stress of different concentrations of salicylic acid-induced,dynamically determinated the activity of chlorophyll,soluble protein,soluble sugar,malonicaldehyde (MDA),free prolin (Pro) content,superoxide dismutase(SOD),peroxidase (POD),hydrogen peroxide enzyme (CAT) ascorbate peroxidase (APX),observed the dynamic trends and chose the best applied concentration.The results showed that,under high temperature stress environment,as the treatment time,the treated plants can effectively alleviate the high temperature damage,improve SOD,POD,APX activities in leaves,inhibit the increase of MDA,increase the accumulation of proline,soluble sugar and show soluble protein and significant differences between the different concentrations.In conclusion,under high temperature stress environment,with the stress treatment time,plants treated by different concentrations of SA can effectively alleviate the high temperature damage.When concentration of SA with 1.5~2.0 mmol·L^-1,the activities of SOD,POD,APX and CAT in leaf were significantly improved;When concentration of SA with 0.5~1.5 mmol·L^-1,the activities of CAT and APX in leaf were significantly improved;The concentration of SA with 1.5~2.0 mmol·L^-1 can effectively inhibit the increase of MDA,proline,soluble sugar and soluble protein accumulation,there are significant differences between the different concentrations.So show that salicylic acid can improve the heat resistance of D.officinale seedlings and 1.5 mmol·L^-1 concentrations can reach the best treatment effect and provide a favorable basis for the facility cultivation of D.officinale.