外源水杨酸对铬胁迫下燕麦种子萌发和幼苗生理特性的影响

Effects of Exogenous Salicylic Acid on Seed Germination and Physiological Characteristics of Oat Seedlings under Chromium Stress

为了探究外源水杨酸(SA)对铬(Cr^(6+))胁迫下燕麦(Avena sativa L.)种子萌发抑制的缓解效应,本试验采用水培法,首先筛选出100 mg/L为适宜的镉胁迫处理浓度,然后设置不同浓度(0.01、0.02、0.03、0.04、0.08、0.10 mmol/L)外源SA浸种处理,以蒸馏水浸种为对照(CK),研究SA对100 mg/L铬胁迫下燕麦种子萌发、幼苗生长、抗氧化酶的活性和渗透调节物质及MDA含量的影响。结果表明,100 mg/L Cr^(6+)溶液胁迫下燕麦种子的萌发和幼苗生长均被显著抑制;外源SA浸种处理能够通过激活燕麦幼苗CAT、POD和SOD等抗氧化酶活性,减少MDA含量,提高可溶性糖和脯氨酸含量,来缓解重金属铬对燕麦种子萌发的毒害作用,进而增强燕麦幼苗的抗逆性。本试验条件下,以0.03 mmol/L外源SA浸种处理的效果较优,明显缓解Cr6+胁迫对燕麦种子萌发、幼苗生长及相关生理指标的抑制。

In order to explore the alleviating effects of exogenous salicylic acid(SA)on the inhibition of chromium Cr^(6+)stress to seed germination of oat(Avena sativa L.),the experiment was conducted by hydro-ponics method.Firstly,the optimal chromium concentration was selected as 100 mg/L,and then different con-centrations(0.01,0.02,0.03,0.04,0.08 and 0.10 mmol/L)of SA were set for seed soaking treatments.The seed soaking treatment with distilled water was set as control.The effects of different SA treatments on seed germination,seedling growth,activities of antioxidant enzymes,and contents of osmotic regulator substances and MDA were studied under 100 mg/L chromium stress.The results showed that seed germination and seed-ling growth of oat were significantly inhibited under the stress of 100 mg/L Cr^(6+).Exogenous SA significantly al-leviated the toxic effect of chromiumon seed germination and thus improved the seedling resistance through ac-tivating CAT,POD and SOD activities,reducing MDA content and increasing soluble sugar and proline con-tents.In the experiment conditions,0.03 mmol/L SA had better effect,which could obviously relieve the inhi-bition of chromium to oat seed germination,seedling growth and related physiological indicators.