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

本课题旨在分析作物在环境胁迫条件下驯化过程中的细胞代谢产物分子。细胞代谢产物计划用基质辅助激光解吸/电离飞行时间质谱仪(MALDI TOF-MS)分析。微量细胞溶液用于分子分析，但由于缺乏合适的激光电离物质，MALDI分析起来并不容易。然而，我们在开发新的MALDI分析矩阵方面取得了进展，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.环境胁迫研究在不同的环境胁迫条件下观察到细胞伸长的抑制。除高温胁迫外，正常植株伸长区的细胞膨胀率在所考察的胁迫条件下保持不变。当胁迫条件作用于植物时，细胞内发生了溶质积累。在极高温下生长的植物的细胞中观察到膨压损失。在胁迫条件下，细胞伸长率与生长诱导水势的大小相关，表明细胞伸长的速度受伸长区细胞吸收水分的多少控制；此外，体细胞胚胎的形成与植物激素的关系进行了研究；此外，还出版了有关植物生理中的水分关系和细胞测量技术的书籍。质谱学研究用于大分子的MALDI TOF-MS的基质化学物质被开发出来。为了研究MALDI质量测量中的裂解与基质化学物质的关系，合成了人工聚合物，并研究了分析物的结构特征和分析物与基质的相互作用。此外，还成功地用MALDI分析了从海藻细胞壁中提取的低聚糖。

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.