一氧化氮对番茄种子抗吸胀冷害的影响

以番茄毛粉802种子为材料,通过对比实验,测定分析各处理种子的萌发率及第4天的平均根长、萌发指数、活力指数,以及相对电导率(REC)、丙二醛(MDA)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)含量的变化,以探讨NO对番茄种子吸胀冷害的抵抗作用及其机理.结果显示:(1)外源NO可显著提高番茄种子经12 h吸胀冷害处理后的萌发率、平均根长、萌发指数和活力指数,并显著降低吸胀冷害下REC和MDA含量,同时显著提高SOD和CAT的含量.(2)NO所提高的吸胀冷害处理后种子的SOD和CAT活性不能被RNA合成抑制剂放线菌素D和蛋白质合成抑制剂环己酰亚胺抑制.结果表明,NO可提高番茄种子抵抗吸胀冷害的能力,而且与NO激活了抗氧化系统有关,但NO不是通过促进抗氧化酶的合成来提高其活性.

Effect of Nitric Oxide on Tomato Seeds Resisting against Chilling Imbibition

In order to study the effect and mechanism of how NO resisting against chilling imbibition tomato(Lycopersicon esculentum Mill.cv.Maofen 802) seeds,germination rate,average root length at the 4th day,germination index,vigor index,relative electrical conductivity(REC),malondialdehyde(MDA) content,the activities of SOD and CAT were determined and analyzed.Results are as follows:(1) the addition of exogenous NO dramatically increased seed germination,average root length,germination index and vigor index after 12 h of chilling imbibition and dramatically decreased the REC and MDA contents,at the same time increased the activities of SOD and CAT.(2) NO induced the increase in the activities of SOD and CAT in tomato seeds during chilling imbibition could not be inhibited by RNA synthetical inhibitor actinomycin D and protein inhibitor cycloheximide.The results indicate that the protecting effects of NO against imbibition may be due to the activation but not the synthesis of NO-dependent antioxidant systems.