茉莉酸甲酯对烟草愈伤组织一些活性氧生成和相关酶活性的影响

Effects of Methyl Jasmonate on the Active Oxygen Production and Related Enzyme Activities in Tobacco Calli

摘要:

烟草愈伤组织用茉莉酸甲酯（MJ，1 mg ml^{-1)处理；同时将愈伤组织在含AIP（0.1mmol/L，水杨酸合成抑制剂）和/或AOA（1 mmol/L，乙烯合成抑制剂）的MS培养基上进行暗培养，测定在活性氧产生和脂质过氧化中起作用的相关酶活性及一些代谢物的含量。结果表明，茉莉酸甲酯能激活超氧阴离子的产生，提高脂氧合酶同工酶1（LOX1）的活性从而启动脂质过氧化，对脂氧合酶同工酶3（LOX3）没有明显影响；降低过氧化氢（H₂O₂）的含量，超氧化物歧化酶（SOD），过氧化氢酶（CAT）及抗坏血酸过氧化物酶（APX）等保护酶的活性，减少了膜脂过氧化中有毒物质丙二醛（MDA）的含量。信号转导途径，MJ调节超氧阴离子和MDA生成，SOD和APX活性很可能是通过乙烯起作用，且对MDA生成和APX活性的调节可能通过水杨酸起作用；MJ直接调节LOX1活性，但对LOX3活性没有明显作用。}

Abstract:

The tobacco calli were cultured on MS or MS containing 0.1 mmo／L 2-aminoindan-2-phosphonic acid (AIP，inhibitor of SA synthesis，gift from Professor B．Mauch．Mani)or l mmol／L aminoxyacetic acid(A0A，inhibitor of ethylene synthesis)in dark(25±2℃)，while methyl jasmonate(MJ) were sprayed to the calli．After treatment，the contents of malondialdehyde(MDA)，active oxygen，hydrogen peroxide(H₂O₂)and the activities of superoxide dismutase(SOD)，lipoxygenase(L0X l and LOX3)，catalase(CAT)，ascorbate peroxidase(APX)were determined during 2-l0 days． MJ largely decreased the content ofM DA，H，O，。and the activities ofSOD，CAT， APX．By contrast，MJ increased the activity of LOX1 and the content of active oxYgen．However．MJ had little effects on the activity of L0X3． The treatment of A0A completely inhibited the effects Of MJ on M DA。active oxygen，SOD and CAT，but，AIP had 1ittle eriects on that substances and enzymes． AIP and AOA differed in the effects on the activity of APX and the MDA content，and had different efects on promoting the LOX activity induced by MJ．The results indicate there are different pathways of signal transduction in the activities of some enzymes and some metabolized substances that involved in the active oxygen burst and lipid peroxide． Ethylene plays a main role in inducing M DA，active oxygen and SOD，but SA had little efects on the induction of these substances． Thus，the effects of MJ are mainly induced by the ethylene pathway． However，SA is essential to the production of MDA and has a particular efect on modulating the activity of SOD under the condition of ethylene deficiency