异甜菊醇对盐胁迫下小麦幼苗生长的影响

为研究赤霉素结构类似物异甜菊醇对盐胁迫条件下小麦幼苗生长的影响,拟开发一种提升小麦抗盐性能的新型植物生长激素。采用滤纸培养法,用NaCl溶液模拟盐胁迫条件,用10^-10~10^-7mol/L异甜菊醇水溶液预处理小麦种子,设置对照组CK（无盐胁迫）和模型组（无预处理）。培养7d后,测定小麦苗长、根长、苗鲜重、根鲜重以及超氧化物歧化酶（SOD）、过氧化氢酶、过氧化物酶活性及丙二醛含量。结果表明,不同浓度的异甜菊醇对盐胁迫条件下小麦幼苗的生长指标及抗氧化酶活性均有一定的提高作用,其中对根生长的促进作用最明显,对SOD活性提高最显著。100mmol/L NaCl盐胁迫条件下,10^-8mol/L异甜菊醇对小麦的抗盐性能提高最佳,与模型组比小麦幼苗根鲜重提高了89.7%,SOD活性提高了53.3%;150mmol/L NaCl盐胁迫条件下,10^-9mol/L异甜菊醇对小麦的抗盐性能提高最佳,与模型组比小麦幼苗根鲜重提高了80.8%,SOD活性提高了203.9%。综上可知,异甜菊醇可通过提高小麦幼苗的抗氧化酶活性来缓解盐胁迫对早期小麦幼苗的生长胁迫,且最适宜异甜菊醇预处理浓度会随盐胁迫浓度不同而不同。

Effects of Isosteviol on Growth of Wheat Seedlings under Salt Stress

To study the influence of early seedling growth of wheat under salt stress by gibberellin structure analogues isosteviol, it is proposed to develop a new plant growth hormone which can improve the salt resistance of wheat. Using filter paper culture method, NaCl solution were simulated as the salt stress condition separately, 10^-10~10^-7mol/L isosteviol water solution were used to soak seeds of wheat, the control group CK (no salt stress) and model group (isosteviol soaking) were established. After seven days of growth, seedling length, root length, seedling fresh weight, root fresh weight, antioxidant enzymes (activities of SOD, CAT, POD) and content of MDA were measured. The results showed that the different contents of isosteviol played a certain role to improve the growth indicators and antioxidant enzyme activity of early wheat seedlings under salt stress, the most obvious role in promoting root growth and SOD activity. Under 100mmol/L NaCl salt stress condition, the best concentration of isosteviol for improving the salt resistance of wheat was 10^-8mol/L. Compared with the model group, the root fresh weight of wheat seedlings increased by 89.7%, and SOD activity increased by 53.3%. Under 150mmol/L NaCl salt stress condition, the best concentration of isosteviol for improving the salt resistance of wheat was 10^-9mol/L, compared with the model group, the root fresh weight of wheat seedlings increased by 80.8%, and SOD activity increased by 203.9%. In conclusion, isosteviol could relieve the stress of salt stress on early growth of wheat seedlings through improving the antioxidant enzyme activity, and the optimum concentration of isosteviol was different with the concentration of salt stress.