三唑酮对绿豆幼苗叶片衰老的延缓作用

RETARDATION OF LEAF SENESCENCE BY TRIADIMEFON TREATMENT IN MUNG BEAN SEEDLING

三唑酮处理可提高离体绿豆（ＰｈａｓｅｏｌｕｓｒａｄｉａｔｕｓＬ．）幼苗叶片叶绿素和蛋白质含量。叶片衰老过程中超氧物歧化酶（ＳＯＤ）、过氧化物酶（ＰＯＤ）、过氧化氢酶（ＣＡＴ）和抗坏血酸过氧化物酶（ＡｓＡＰＯＤ）活性及抗坏血酸（ＡｓＡ）和还原型谷胱甘肽（ＧＳＨ）含量降低。２０ｍｇ／Ｌ三唑酮可提高ＰＯＤ、ＡｓＡＰＯＤ活性和ＡｓＡ、ＧＳＨ含量，对ＳＯＤ、ＣＡＴ活性无影响。丙二醛（ＭＤＡ）含量在叶片衰老过程中提高，并与ＰＯＤ、ＡｓＡＰＯＤ活性和ＡｓＡ、ＧＳＨ含量呈显著负相关，三唑酮可降低ＭＤＡ含量。表明三唑酮有提高植物对膜脂过氧化作用的保护能力，延缓叶片的衰老作用。

Treatment of triadimefon on detached leaves of mung bean (Phaseolus radiatus L.) seedlings increased the levels of chlorophyll and soluble proteins. Declined activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbateperoxidase (AsAPOD) and contents of ascorbate (AsA) and glutathione (GSH) were observed during the senescence of detached young leaves. Triadimefon at concentration of 20 mg/L promoted the activities of POD,AsAPOD and levels of AsA and GSH, but had no effect on the activities of SOD and CAT. On the other hand, the levels of malondialdehyde (MDA) were increased and the increase of which was markedly negative correlated with the activities of POD, AsAPOD and with the contents of AsA and GSH during the senescence of leaves. MDA contents were decreased by triadimefon treatment. These results suggested that triadimefon retarded the senescence of leaves in mung bean seedlings in terms of enhancing the protective ability of plant tissues against membrane lipid peroxidation.