外源水杨酸对小麦幼苗镍毒害的缓解效应

为了解外源水杨酸(SA)对小麦镍胁迫的缓解作用,以小麦品种陇春3031为材料,采用溶液培养法,研究了不同浓度的SA对1 mmol·L-1 Ni2+胁迫下小麦幼苗生长及生理指标的影响。结果表明,1mmol·L-1 Ni2+胁迫显著降低了小麦幼苗的鲜重、干重、叶绿素含量、脯氨酸含量、过氧化物酶(POD)活性,显著提高了小麦幼苗丙二醛(MDA)含量。与单独Ni2+胁迫相比,0.1和0.5mmol·L-1 SA处理,可显著提高小麦幼苗地上部和根的鲜重和干重(P0.05),增加小麦幼苗叶绿素a、叶绿素b和总叶绿素含量,且叶绿素a/b显著升高。0.1mmol·L-1 SA处理,小麦幼苗总叶绿素含量升高了37.77%;提高了小麦幼苗叶和根中的POD活性和叶中的脯氨酸含量,降低了小麦幼苗根中脯氨酸含量;有效抑制了小麦叶和根中MDA含量的增加。说明适宜浓度的SA处理能缓解镍胁迫对小麦幼苗的毒害,增强其抗镍胁迫能力。

Mitigation Effect of Exogenous Salicylic Acid on Wheat Seedlings under Nickel Stress

To understand the mitigation effects of exogenous salicylic acid (SA) to wheat seedings under nickel stress,the effects of different concentrations SA on wheat seedings exposed to 1 mmol·L^-1 Ni²⁺ were studied through hydroponic method. The results showed that 1 mmol·L^-1 Ni²⁺ significantly decreased fresh weights and dry weights,the contents of chlorophyll,proline and the activity of peroxidase (POD),increased the accumulation of malondialdehyde (MDA) of wheat seedling. Compared with the single Ni²⁺ stress,the fresh and dry weights of shoot and root of wheat seedlings were significantly increased when 0.1 and 0.5 mmol·L^-1 SA were used (P<0.05). It was also found that SA could increase the contents of chlorophyll a,chlorophyll b,total chlorophyll and the ratio of chlorophyll a/b,0.1 mmol·L^-1 SA increased total chlorophyll contents in leave of wheat by 37.77%. Exogenous SA improved the activities of POD in shoot and root and proline in leaves,while decreased proline in root,effectively inhibited the amount of MDA in shoot and root. 0.1 mmol ·L^-1 SA decreased MDA content in leaves by 30.84%,0.5 mmol·L^-1 SA decreased MDA content in roots by 25.76%. Above results indicated that exogenous SA could alleviate harmfulness of nickel stress and enhance the nickel resistance of wheat seedings.