【摘要】 以盐生植物盐芥为材料,中生植物拟南芥为对照,研究了NaCl胁迫下盐芥和拟南芥叶片Na+含量、化合物含量和蛋白质结构变化的差异.应用傅立叶红外光谱(FTIR)的分析方法,揭示了拟南芥和盐芥叶片中酯类、蛋白质、碳水化合物含量、蛋白质二级结构在盐胁迫下的不同响应.结果表明,随着200mmol/LNaCl胁迫0~48h,盐芥叶片中蛋白质和酯类含量持续增加,碳水化合物含量逐渐降低,仍比拟南芥的含量高出30%;而拟南芥在50mmol/LNaCl胁迫下的蛋白质、碳水化合物和酯类合成量逐渐降低.应用曲线拟合酰胺I区波峰,分析发现叶片中蛋白质二级结构有1668cm-1和1638cm-1两个组成部分.通过比较发现,盐芥与拟南芥叶片中酰胺I区1668cm-1波峰面积随时间延长而逐渐增加的变化趋势相似,而盐芥叶片中1638cm-1波峰面积比拟南芥的显著增加,因此使盐芥的1668/1638cm-1比值逐渐降低,拟南芥1668/1638cm-1比值逐渐升高.由此揭示,盐芥植株通过增强的蛋白质、酯类合成代谢调控能力抵御盐胁迫的损伤,而且盐芥叶片总蛋白质二级结构比拟南芥的更趋稳定,与叶片中Na+含量的变化趋势显著相关.因此盐芥为了适应高浓度盐胁迫,具有叶片蛋白质、酯类快速合成以及蛋白质构象更趋于稳定的积极响应.图6表1参29更多还原

【Abstract】 A technique based on Fourier transform infrared (FTIR) spectrometry was used to detect the corresponding changes in chemical composition which associated with the rapid changes in sodium with 200 mmol/L NaCl stressed halophyte Thellungiella halophila. The changes in glycophyte Arabidopsis thaliana stressed with 50 mmol/L NaCl were also examined for comparison. The results showed that within 48 h of mild salt stress, the absorption band intensities in the fingerprint region decreased continuously in both the plants, suggesting that the carbon assimilation was affected at the early stage of stress. The intensities of ester and amide I absorption bands decreased slightly in A. thaliana, but increased in T. halophila, suggesting that the cell expansion and protein synthesis ceased in A. thaliana but continued in T. halophila. In the two plants, the analysis of the ratio between 1 668 and 1 638 cm-1 in amide I absorption bands revealed that T. halophila was able to maintain a higher-ordered form of proteins under the stress. Furthermore, the changes in protein conformation showed a positive correlation with the sodium contents in T. halophila leaves. Fig 6, Tab 1, Ref 29更多还原