NaCl胁迫对茄子嫁接幼苗叶片抗坏血酸和谷胱甘肽代谢的影响

以Torvum Vigor为砧木,栽培品种苏崎茄为接穗,研究NaCl胁迫对茄子嫁接苗和自根苗抗氧化物质含量和H2O2产生及清除酶活性的影响.结果表明;(1)NaCl胁迫可诱导叶片中H2O2的产生,导致膜脂过氧化产物丙二醛(MDA)的积累,嫁接苗叶片中H2O2和MDA的含量显著低于自根苗.(2)在NaCl胁迫下,嫁接苗叶片中谷胱甘肽还原酶(GR)和抗坏血酸过氧化物酶(APX)活性上升,自根苗则下降;NaCl胁迫促进了嫁接苗还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)的合成,嫁接苗叶片中AsA和GSH的含量显著高于自根苗.由此认为,茄子嫁接苗耐盐性优于自根苗的原因之一在于嫁接苗保持较快的AsA-GSH循环,从而保证GSH和AsA的再生以减轻氧化损伤.

Metabolism of Ascorbic Acid and Glutathione in Leaves of Grafted Eggplant Seedlings under NaCl Stress

Using 'Torvum Vigor'(Solanum torvum Swartz) as rootstock and eggplant cultivar 'Suqiqie'(Solanum melongena L.) as scion,we studied the effects of NaCl stress on the contents of antioxidants,generation of hydrogen peroxide(H2O2) and H2O2-scavenging system in leaves of both grafted and own-root seedlings.The results showed that NaCl stress induced generation of H2O2 and accumulation of malondiadehyde(MDA) both in grafted and own-root seedlings.However,contents of H2O2 and MDA in leaves of grafted seedlings were significantly lower than those of own-root seedlings.The activities of glutathione reductase(GR) and ascorbate-specific peroxidase(APX) in leaves of grafted seedlings were significantly increased whereas those of own-root seedlings were decreased under NaCl stress.NaCl stress stimulated the synthesis of ascorbic acid(AsA) and reduced glutathione(GSH) in grafted seedlings.Contents of AsA and GSH in leaves of grafted seedlings were significantly higher than those of own-root seedlings.It was concluded that a rapid cycle of AsA-GSH which ensured regeneration of AsA and GSH to reduce oxidative damage might be involved in the stronger salt tolerance of grafted eggplant seedlings.