等渗盐胁迫对番茄抗氧化酶和ATP酶及焦磷酸酶活性的影响

Effects of Iso-osmotic Salt Stress on the Activities of Antioxidative Enzymes, H^+-ATPase and H^+-PPase in Tomato Plants

用Ca(NO3)2 80 mmol/L和NaCl 120 mmol/L等渗溶液处理番茄幼苗后,细胞质和叶绿体中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)的活性升高,并且NaCl胁迫的作用明显高于Ca(NO3)2胁迫。Ca(NO3)2处理提高了线粒体中SOD、CAT、APX的活性,而NaCl处理降低了它们的活性。根系质膜H+-ATPase、液泡膜H+-ATPase、焦磷酸酶(H+-PPase)的活性和叶片丙二醛(MDA)及脯氨酸含量在两种盐胁迫后明显增加。NaCl处理对植株生长的抑制程度明显高于Ca(NO3)2处理。

Seedlings of tomato (Lycopersicon esculentum Mill.) were grown in nutrient solution to investigate the changes in malondialdehyde (MDA) and proline content, and activities of antioxidative enzymes, plasma-lemma H+-ATPase, and tonoplast H+-ATPase and H+-PPase to iso-osmotic stress of Ca(NO3)2 (80 mmol/L) and NaCl (120 mmol/L). The results indicated that both Ca(NO3)2 and NaCl stress significantly increased superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities in leaf cytosols and chloroplasts (Fig.3A-C). The extent of increase caused by NaCl was higher than that by Ca(NO3)2. The activities of SOD, CAT and APX in mitochondria were increased under Ca(NO3)2 stress and decreased under NaCl stress (Fig.3A-C). Salt stress enhanced the activities of plasmalemma H+- ATPase, tonoplast H+-ATPase and H+-PPase (Fig.4A-C). The increases in tonoplast H+-AT-Pase and H+-PPase activity were much higher under Ca(NO3)2 stress than under NaCl stress. The MDA and proline content increased under salt stress, especially under NaCl stress (Fig.2). From the results, it can be concluded that both salt inhibited the plant growth, the effect of NaCl being much heavier.