用超微细胞化学定位技术揭示ATP酶在紫茎泽兰高温适应性中的作用

Studies on adaptability to high temperature of Eupatorium adenophorum by ATPase ultracytochemical localization

【背景】外来入侵植物紫茎泽兰自然演化出耐高温种群,其适应机制与各种生理代谢有关。【方法】本文从超微细胞化学水平,对紫茎泽兰抗高温种群、敏感种群ATP酶活性定位,明确其在高温适应性中的作用,试图阐明该草的生态适应机制。【结果】正常情况下,紫茎泽兰ATP酶主要定位于细胞壁及细胞间隙周围的细胞壁表面;经40℃高温处理后,在不同的处理时间下,抗性、敏感种群之间ATP酶的活性表现出明显差异,其中以处理12h时差异最大,具体表现为抗高温种群的ATP酶活性明显高于敏感种群,ATP酶的定位点除细胞壁外,在细胞膜上也呈现大量的分布,而敏感种群在处理12h时的酶活性明显降低,只在细胞壁上有零星的分布。处理24h时,敏感种群叶片已完全萎蔫,细胞结构毁坏,细胞膜破损;而抗高温种群叶片仍然完好,细胞膜上仍有ATP酶分布。【结论与意义】经40℃高温处理后,紫茎泽兰抗高温种群ATP酶活性明显高于敏感种群,初步认为紫茎泽兰对高温的适应性与ATP酶活性相关。本研究为进一步阐明与紫茎泽兰适应性相关的入侵机理提供了资料。

[ Background ] Invasive organisms have to adapt to the stresses in their new enviomments. This can include adaptation to heat stress, known to occur in plants. There is evidence that such adaptation to heat stress is related to various physiological metabo- lisms. [ Method] Ultrastrutural cytochemical localization of ATPase activity of beat-resistant and susceptible populations of Eupatori- um adenophorum （ Spreng. ） was investigated to explore the role of ATPase activity and distribution in the cell. [ Result ] The AT- Pase of E. adenophorum naturally was located at the cell wall and the surface of cell wall bordering the intercellular spaces. ATPase activity in resistant vs. susceptible populations at 40℃ high temperature had significant difference and was recorded 12 hours after heat treatment was applied. ATPase of the resistant populations remained active on many localized sites, including the cell wall and plasma membranes, whereas ATPase activity of susceptible populations obviously decreased, with only sporadic activity spots remaining on the cell wall. Twenty-four hours later, the leaves of susceptible populations completely wilted whereas some dots of ATPase were found on plasma membranes of resistant populations and the chloroplast uhrastructure was only slightly damaged. [ Conclusion and significance] After treatment at 40℃, high temperature resistant populations of E. adenophorum ATPase activity was less damaged than in the temperature-susceptible populations, indicating that E. adenophorum adaptability to high temperature may be associated with ATPase activity and thus to invasion success.