NO对盐胁迫下长春花种子萌发和幼苗生理代谢的影响

为探讨NO对盐胁迫下长春花（Catharanthus roseus）种子萌发及幼苗生长的缓解作用，在50 mmol·L^-1 NaCl胁迫下，研究了不同浓度外源NO供体硝普钠（SNP）处理对长春花种子萌发及幼苗生理代谢的影响。研究表明：盐胁迫抑制长春花种子萌发，0.1 mmol·L^-1 SNP缓解盐胁迫对长春花种子萌发和幼苗生长效果最好，显著提高种子发芽率、发芽指数、活力指数和叶片中脯氨酸（Pro）含量，降低了丙二醛（MDA）含量，0.1~0.5 mmol·L^-1 SNP下硝酸还原酶（NR）活性增强，大于0.5 mmol·L^-1 SNP加重盐胁迫伤害。适当浓度的NO可有效缓解盐胁迫对长春花种子和幼苗的伤害。

Effects of Exogenous NO on Seed Germination and Physiological Metabolism in Catharanthus roseus Seedling under NaCl Stress

Under 50 mmol·L^-1 NaCl stress condition, we studied the relaxation effects of sodium nitroprusside(SNP, an exogenous nitric oxide donor) at the contents of 0.05, 0.1, 0.5, 1.0 and 2.0 mmol·L^-1 on germination and physiological metabolism in Catharanthus roseus seedlings. The results showed that NaCl stress inhibited the germination of C.roseus and SNP could alleviate its stress effect. At the 0.1 mmol·L^-1 of SNP the seed germination, germination and vitality index, and contents of proline in leaves were increased significantly, while malondialdehyde(MDA) content in leaves were decreased dramatically. Nitrate reductase(NR) activities in 0.1-0.5 mmol·L^-1 SNP groups reached to higher levels compared to that of control group. However, more than 0.5 mmol·L^-1 SNP enhanced the stress effect of NaCl. Therefore, the 0.1 mmol·L^-1 was the most appropriate content for SNP to alleviate NaCl stress. In conclusion, appropriate contents of exogenous NO could alleviate NaCl stress on C.roseus seeds and seedlings effectively.