油菜素内酯对硝酸钙胁迫下黄瓜幼苗生长及其抗氧化酶同工酶表达的影响

Effects of Brassinolide on the Growth and Isozyme Expression of Antioxidant Enzymes of Cucumber Seedlings Under Calcium Nitrate Stress

采用营养液水培,研究硝酸钙胁迫下油菜素内酯(BR)对黄瓜幼苗生长及其抗氧化酶同工酶表达的影响。结果表明,硝酸钙胁迫至第9天,黄瓜幼苗干鲜重下降,生长受到了显著的抑制,而硝酸钙胁迫下施用BR,黄瓜幼苗生长受抑制程度减轻,其鲜重、干重较单纯硝酸钙处理显著增加。硝酸钙胁迫增强了黄瓜幼苗超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)同工酶的表达,硝酸钙胁迫下施用外源BR的第6 d,SOD、POD同工酶的表达比硝酸钙处理分别提高了14.77%、17.49%,第9天POD同工酶的表达比硝酸钙处理提高了16.59%,而CAT同工酶的表达变化均不明显。可见,硝酸钙胁迫抑制了黄瓜幼苗的生长,硝酸钙胁迫下施用BR可调节黄瓜幼苗SOD、POD同工酶的表达,并缓解硝酸钙胁迫对黄瓜幼苗的伤害。

Ahydroponic experiment was conducted to study the effects of brassinolide （BR）on the growth and isozyme expression of antioxidant enzymes of cucumber seedling under calcium nitrate stress. These results showed the growth of cucumber seedlings were significantly inhibited while BR alleviated the growth inhibition in cucumber seedling which induced by calcium nitrate with increasing more fresh weight and dry weight after 9 days calcium nitrate stress and calcium nitrate induced the expression of superoxide dismutase（SOD）, catalase （CAT）and peroxidase（POD）. However, BR increased the expression of SOD and POD isozymes by 14.77 % and 17.49% on the day 6 and decreased the expression of POD by 16.59% on the day 9.Our results suggested that calcium nitrate stress inhibited the growth of cucumber seedling and BR might regulate the isozyme expression of autioxidant enzymes of cucumber seedling and alleviated the damage effects of calcium nitrate stress to cucumber seedling.