外源NO对镉胁迫下黑麦草生长的缓解效应

为研究外源NO对Cd胁迫下黑麦草生长的缓解效应,采用营养液培养,研究了不同浓度硝普钠对100μmol/L CdCl2胁迫下黑麦草生理特性的影响。结果表明,SNP能显著缓解Cd胁迫对黑麦草植株造成的伤害,可明显提高黑麦草的生长量、叶绿素含量、脯氨酸(Pro)含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs),降低过氧化氢(H2O2)含量、超氧阴离子(O2.-)产生速率、胞间CO2浓度(Ci);抑制了Cd向地上部的转运,与100μmol/L SNP处理相比,50、200和400μmol/L SNP处理对黑麦草Cd胁迫的缓解作用明显降低。说明适宜浓度的外源NO作为化学诱抗剂,可以诱导黑麦草的抗逆性的增强,减轻和缓解Cd胁迫的伤害。

Ameliorating Effects of Exogenous Nitric Oxide on Ryegrass Seedlings under Cadmium Stress

The aim of the experiment was to study the ameliorating effects of exogenous nitric oxide on growth of ryegrass seedlings under cadmium stress.A hydroponic experiment was conducted to investigate the effects of different concentrations of sodium nitroprusside(SNP),a NO donor,on physiological characteristics of ryegrass under 100 μmol/L CdCl2 stress.The results showed that exogenous sodium nitroprusside(SNP) significantly alleviated the stress damage to ryegrass under 100 μmol/L CdCl2 stress,and increased the growth amount,the contents of chlorophyll and proline,the net photosynthetic rate(Pn),the transpiration rate(Tr),the stomata conductance(Gs),reduced H2O2 content,O2·-generation rate,intercellular CO2 concentration(Ci),significantly inhibit the transportation of Cd from root to shoot.When treated with 50 or 200 or 400 μmol/L of SNP,ameliorating effects on ryegrass were obviously decreased compared with 100 μmol/L of SNP treatment.It is proposed that exogenous NO as chemical activator could induce stress resistance,and alleviate damage degree of Cd stress to ryegrass seedlings.