Non-destructive measurement techniques of metabolite molecules in cells of crop plants

本研究旨在分析作物在环境胁迫条件下驯化过程中的细胞代谢物分子。计划使用基质辅助激光解吸/电离飞行时间质谱仪（MALDI TOF-MS）分析细胞代谢物。微量细胞液可用于分子分析，但由于缺乏合适的激光电离基质，MALDI分析不容易。然而，我们在开发用于MALDI分析的新基质方面取得了进展，我们报告了与环境胁迫条件下的植物生理学研究和MALDI研究相关的结果如下：1.环境胁迫研究在各种环境胁迫条件下，细胞伸长受到抑制。在除高温胁迫外的胁迫条件下，完整植株伸长区的细胞膨压保持恒定。当胁迫条件施加到植物上时，细胞中发生溶质积累。在极高温度下生长的植物细胞中观察到膨压损失。胁迫条件下，细胞伸长速率与生长诱导水势大小相关，表明细胞伸长速率受伸长区细胞吸收水分的调节;此外，还研究了体细胞胚形成与植物激素的关系，并整理了植物生理学中水分关系和细胞测量技术方面的相关书籍.质谱研究开发了用于大分子MALDI TOF-MS的基质化学品。为了研究MALDI中质谱裂解与基质化学物质之间的关系，合成了人工高分子，研究了分析物的结构特征和分析物-基质的相互作用。此外，从海藻细胞壁中提取的寡糖成功地进行了MALDI分析。

This project was undertaken to analyze cell metabolite molecules of crop plants during acclimation process under environmental stress conditions. Cell metabolites were planned to be analyzed with matrix-assisted laser desorption/ionization time-of-flight mass spectrometers (MALDI TOF-MS). Minute volume of cell solution was used for molecular analysis, but the analysis was not easy with MALDI due to lack of proper matices for laser ionization. However, we progressed for the development of new matrices for MALDI analyses, and we report results related to plant physiology research under environmental stress conditions and MALDI research as follows;1. Environmental stress researchInhibition of cell elongation was observed under various environmental stress conditions. Cell turgor in the zone of elongation of intact plants was kept constant under stress conditions examined except high temperature stress. Solute accumulation took place in cells when stress conditions were applied to plants. Turgor loss was observed in cells of plants grown under extremely high temperature. Rates of cell elongation were correlated with sizes of the growth-induced water potential under stress conditions, indicating that the speed of cell elongation was regulated by how much water was absorbed by cells in the zone of elongation.Additionally, formation of somatic embryos was studied with relation with plant hormones.Furthermore, books related to water relations in plant physiology and cell measurement techniques were published.2. Mass spectrometry researchMatrix chemicals were developed for MALDI TOF-MS for macromolecules. To study relations between fragmentation in mass measurements and matrix chemicals for MALDI, artificial polymers were synthesized, and structural characteristics of analytes and interactions of analyte-matrix were studied. Furthermore, oligosaccharides extracted from seaweed cell walls were successfully analyzed with MALDI.