硝普钠缓解镧引起的黑麦草幼苗生长抑制和根系氧化损伤

采用水培方法，研究了外源一氧化氮（NO）供体硝普钠（SNP）对300 μmol·L^-1 LaCl₃胁迫下黑麦草幼苗生长和根系活性氧代谢的影响。结果表明：在LaCl₃胁迫下，喷施50 μmol·L^-1 SNP能够抑制镧（La）从黑麦草根系向地上部的转运，缓解La对幼苗生长的抑制作用；提高幼苗根系超氧化物歧化酶和抗坏血酸过氧化物酶活性，降低过氧化物酶活性及谷胱甘肽、脯氨酸、H₂O₂、丙二醛含量、超氧阴离子产生速率和质膜相对透性，对过氧化氢酶活性和抗坏血酸含量无显著影响。表明NO可通过活性氧代谢的调节，缓解高浓度La胁迫对黑麦草幼苗生长的抑制作用。

Alleviation of SNP on Growth Inhibition and Root Oxidative Damage Caused by Lanthanum in Ryegrass Seedlings

Hydroponic experiments were conducted to study the effects of exogenous nitric oxide (NO) donor sodium nitroprusside (SNP) on the growth and root reactive oxygen species metabolism in ryegrass (Lolium perenne L.) seedlings under 300 μmol·L^-1 LaCl₃ stress. The results showed that under the stress, spraying 50 μmol·L^-1 SNP significantly inhibited the transportation of lanthanum (La) from root to shoot in ryegrass seedlings, alleviated the inhibition effect of La on the seedlings growth, increased the activities of superoxide dismutase and ascorbate peroxidase, significantly decreased peroxidase activity, the contents of reduced glutathione, proline, H₂O₂ and malondialdehyde, and O₂^-· production rate as well as plasma membrane relative permeability in the seedling roots, but had no effect on catalase activity and ascorbic acid content. The results indicated that NO could alleviate the growth inhibition of ryegrass seedlings caused by high concentration La stress via adjusting the root reactive oxygen species metabolism.