水杨酸对低氧胁迫苦瓜幼苗生理特性的影响

Effects of Salicylic Acid on Physiological Characteristics of Bitter Gourd Seedlings under Hypoxia Stress

低氧胁迫是限制苦瓜生长的主要因子,水杨酸(SA)作为植物体内的信号分子,为探明SA对低氧胁迫苦瓜的调控作用,本试验以白玉苦瓜为材料,研究低氧胁迫下施用外源不同浓度SA(0,0.25,0.5,1.0,2.0 mmol/L)对苦瓜幼苗膜质过氧化、渗透调节物质、抗氧化酶、根系呼吸的影响。结果表明,外源SA能够降低苦瓜幼苗膜质过氧化程度、提高抗氧化酶活性、增加渗透调节能力、减弱无氧呼吸,促进有氧呼吸,从而提高苦瓜低氧耐性。随着低氧胁迫时间的延长,0.25、0.5、1.0 mmol/L的SA对苦瓜幼苗低氧胁迫的缓解能力随着SA浓度的增加而提高,但是2.0 mmol/L SA则有降低的趋势。总体而言,1.0 mmol/L的SA对苦瓜低氧伤害的缓解效果最佳,本研究为SA调控苦瓜的耐低氧栽培提供了理论依据,也为SA在植物抗逆分子水平研究提供了参考。

Hypoxia stress is a limiting factor that limits the growth of bitter gourd.Salicylic acid(SA)is a signal molecule in plants.In order to explore the regulatory effect of SA on bitter gourd under hypoxia stress,the'Baiyu'bitter gourd was used to study the effects of different concentrations of SA(0,0.25,0.5,1.0,2.0 mmol/L)on membrane peroxidation,osmotic regulatory substances,antioxidant enzymes and root respiration of bitter gourd seedlings under hypoxia stress.The results showed that exogenous SA could reduce the degree of membrane peroxidation,increase the activity of antioxidant enzymes,increase the osmotic regulation ability,weaken anaerobic respiration,promote aerobic respiration,and improve the hypoxia tolerance of bitter gourd seedlings.With the prolongation of hypoxic stress time,the alleviating ability of 0.25,0.5 and 1.0 mmol/L SA under hypoxic stress increased along with the SA concentration,but 2.0 mmol/L SA tended to decrease.In general,1.0 mmol/L SA had the best alleviating effect on bitter gourd seedlings under hypoxia stress,the study provided theoretical basis for the regulation of SA in hypoxic cultivation of bitter gourd and also provided reference for the molecular level study of SA in plant resistance.