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为探讨活性氧和细胞质钙离子在小麦抗条锈病反应中的作用,以小麦品种洛夫林13与具有不同致病力的单孢锈菌CY29、CY25的互作体系为平台,对锈菌侵染后小麦叶片中活性氧(ROS)积累、保护酶系(SOD、CAT和APX)活性变化动态、细胞质膜的透性改变及细胞质钙离子浓度变化做了研究。结果表明,不亲和锈菌CY25侵染可引起小麦叶片内2次ROS的爆发,第1次出现在接种后前期(接种后第2天),强度较小,第2次出现在接种后期(接种后第5天),强度较大;亲和锈菌CY29侵染只引起1次ROS爆发,出现在接种后期(接种后第5和第6天之间),但强度极大。过敏性坏死反应HR只出现在不亲和互作小麦叶片上前期ROS爆发之后,表明前期ROS爆发与HR的产生有关。伴随着后期小麦叶片中强度极高的ROS的爆发,叶片细胞原生质膜遭到了破坏,细胞内物质外渗,细胞不久便死亡,表明高强度的ROS爆发会导致细胞死亡。根据不同互作体系ROS爆发时期SOD、CAT和APX等保护酶的活性变化分析,不亲和互作体系前期强度较小的ROS爆发主要成分是H2O2,后期强度较高的ROS爆发主要成分是O2.-和H2O2;亲和互作体系强度极高的ROS爆发主要成分是O2.-和H2O2。由此说明H2O2是引起小麦抗病反应HR发生的因素,而O2.-则是引起细胞死亡的因素。细胞质钙离子浓度变化研究表明,HR的发生与细胞质钙离子浓度增加相关。细胞质钙离子浓度的降低推迟了HR的发生,这说明小麦叶片细胞内细胞质钙离子浓度的增加是HR的必要条件,同时也说明Ca2+是植物HR的胞内第二信使参与植物抗病防卫反应。
In order to explore the role of reactive oxygen species (ROS) and cytoplasmic calcium ions in the resistance to stripe rust of wheat, the interaction between LOVINE 13 and CY29 and CY25 with different pathogenicity was used as the platform. The accumulation of reactive oxygen species (ROS), the dynamic changes of protective enzymes (SOD, CAT and APX), the changes of plasma membrane permeability and the change of cytoplasmic calcium concentration in dyed wheat leaves were studied. The results showed that the inactivation of CY25 caused two outbreaks of ROS in wheat leaves, the first appeared in the early post-inoculation (the second day after inoculation), the less intense, and the second appeared in the late inoculation stage On day 5 after inoculation, the intensity was high. Infection with pro-rust CY29 caused only one ROS burst, which occurred in the late stage of inoculation (between the 5th and 6th day after inoculation), but the intensity was very high. The HR of allergic necrosis only appeared after the previous ROS burst on incompatible intercropping wheat leaves, indicating that the early ROS outbreak was related to the production of HR. With the outbreak of high-intensity ROS in late-stage wheat leaves, the plasma membrane of the leaf cells was destroyed and extracellular material was extravasated and the cells died shortly thereafter, indicating that high-intensity ROS burst leads to cell death. According to the analysis of changes in the activity of SOD, CAT and APX during the period of ROS burst, the main component of the ROS in the early phase of the non-affinity interaction system is H2O2. The main component of the ROS in the later phase is O2 .- and H2O2; the major components of the ROS burst with high affinity for the affinity system are O2.- and H2O2. This shows that H2O2 is the cause of disease resistance in wheat HR factor, and O2.- is the cause of cell death. Cytoplasmic Ca2 + concentration changes studies have shown that the occurrence of HR and cytoplasmic Ca2 + concentration increases. The decrease of cytoplasmic Ca2 + concentration delayed the occurrence of HR, which indicated that the increase of cytoplasmic Ca2 + concentration in wheat leaves was a necessary condition for HR. It also indicated that Ca2 + was the intracellular second messenger of plant HR and was involved in plant defense response.