【作者】 张云英；

【导师】 佘小平；

【作者基本信息】 陕西师范大学 ， 植物学， 2009， 硕士

【摘要】 研究证实过氧化氢（H₂O₂）、一氧化氮（NO）和一氧化碳（CO）均介导脱落酸（ABA）诱导的气孔关闭,也有资料显示壳梭孢素（fusicoccin,FC）有促进气孔开放的效应,但时止今日尚未清楚ABA诱导气孔关闭中CO与H₂O₂的关系,FC抑制ABA诱导的气孔关闭与保卫细胞H₂O₂、NO变化的关系也未见研究。本文以蚕豆为材料,借助表皮条试验和激光共聚焦扫描显微镜（LSCM）技术对上述问题进行了探索。所得结果主要如下:1.ABA、CO合成底物亚铁血红素（Ht）、CO水溶液和H₂O₂均表现促进气孔关闭的效应,CO产生酶亚铁血红素加氧酶-1（HO-1）专一性抑制剂锌原卟啉（ZnPPIX）、H₂O₂清除剂抗坏血酸（Vc）、过氧化氢酶（CAT）和H₂O₂产生酶NADPH氧化酶抑制剂二苯基碘（DPI）均抑制ABA诱导气孔关闭,Ht诱导的气孔关闭也被Vc、CAT和DPI抑制,这些结果暗示ABA可能通过诱导保卫细胞CO合成增加H₂O₂产生,进而促进气孔关闭。内源H₂O₂检测结果表明,ABA和Ht确有诱导保卫细胞H₂O₂产生的作用,而且ABA促进保卫细胞H₂O₂产生的作用可被ZnPPIX明显抑制,此与前述表皮条试验的结果完全一致。2.与H₂O₂清除剂Vc、CAT和H₂O₂产生酶NADPH氧化酶抑制剂DPI一样,FC抑制ABA诱导气孔关闭并降低保卫细胞内源H₂O₂水平,表明FC通过降低保卫细胞H₂O₂水平抑制ABA诱导气孔关闭;与H₂O₂清除剂Vc、CAT类似,FC不仅阻止外源H₂O₂诱导气孔关闭、降低保卫细胞H₂O₂荧光,而且促进ABA诱导下已关闭气孔重新开放、降低ABA诱导下已产生的内源H₂O₂,但H₂O₂产生酶NADPH氧化酶抑制剂DPI却无上述效应,这些结果说明FC可能通过清除而非抑制合成降低保卫细胞H₂O₂水平,进而抑制ABA诱导气孔关闭。3.与NO专一性清除剂c-PTIO、NO合酶（NOS）抑制剂L-NAME一样,FC抑制ABA诱导气孔关闭并降低保卫细胞内源NO水平,表明FC通过降低保卫细胞NO水平抑制ABA诱导气孔关闭;与NO专一性清除剂c-PTIO类似,也能通过降低保卫细胞NO水平抑制ABA诱导的气孔关闭。与NO专一性清除剂c-PTIO相类似,FC不仅阻止外源NO供体硝普钠（SNP）诱导气孔关闭、降低保卫细胞NO荧光,而且促进ABA诱导下已关闭气孔重新开放、降低ABA诱导下已产生的内源NO,但NOS抑制剂L-NAME却无上述效应,这些结果说明FC可能通过清除而非抑制合成降低保卫细胞NO水平,进而抑制ABA诱导气孔关闭。更多还原

【Abstract】 Previous studies showed that CO, H₂O₂ and NO are involve in ABA-induced stomatal closure, and stomatal opening is induced by fusicoccin （FC）. However, the role of CO-mediated H₂O₂ in ABA-induced stomatal closure remains unclear. Also, the effect and action mechanism of FC on ABA-induced stomatal closure are unkown. In the present study, by means of the epidermal strip bioassay and the laser scanning confocal microscopy（LSCM）, it was investigated that the relationship of CO and H₂O₂ in ABA-induced stomatal closure and the effects and action mechanism of FC on stomatal closure induced by ABA. The main results are as followed:1. Stomatal closure were induced by ABA, CO synthesis substrate Hematin （Ht）, CO aqueous solution and H₂O₂, ABA-induced stomatal closure was restrained by ZnPPIX （CO specific synthetic inhibitor）, CAT（catalase）, Vc（H₂O₂ scavenger） and DPI（an inhibitor of H₂O₂ generating enzyme NADPH oxidase）, Ht-induced stomatal closure was also prevented by CAT, Vc and DPI. The results suggest that CO Synthesis may mediate ABA-induced H₂O₂ production and stomatal closure. The examination results of endogenous H₂O₂ showed that ABA and Ht induce increase of H₂O₂. However, ABA-induced the production of endogenous H₂O₂ was significantly prevented by ZnPPIX. These results were in accordance with the epidermal strip bioassay.2. Like CAT. Vc and DPI, FC inhibited ABA-induced stomatal closure and reduced the level of endogenous H₂O₂ in guard cells, which indicated that FC inhibited ABA-induced stomatal closure by reducing endogenous H₂O₂ level. Like CAT and Vc, FC not only prevented stomatal closure induced by exogenous H₂O₂, reduced H₂O₂ fluorescence of guard cells treated by exogenous H₂O₂, but also promoted the closed stoma induced by ABA to reopen, abolished H₂O₂ that had been generated by ABA. However, DPI had no the effects mentioned above. Taken together, our results indicate that FC probably reduce the levels of H₂O₂ in guard cells by scavenging, not restraining H₂O₂ generation, and then prevent ABA-induced stomatal closure.3. Like c-PTIO（NO scavenger） and L-NAME（NO synthase inhibitor）, FC prevented ABA-induced stomatal closure and reduce the level of endogenous NO in guard cells, which indicated that FC prevented ABA-induced stomatal closure by reducing the level of endogenous NO. Like c-PTIO, FC not only prevented SNP-induced stomatal closure, reduced NO fluorescence of guard cells treated by SNP, but also promote the closed stoma induced by ABA to reopen, abolished NO that had been generated by ABA. However, L-NAME had no the effects mentioned above. Hence, it is concluded that FC reduce probably the levels of NO in guard cells via scavenging, not preventing NO generation, and then prevent ABA-induced stomatal closure.更多还原