Regulation of Water-Stress Protein Synthesis

地木耳是一种固氮光合蓝藻 具有耐干燥的能力。 该微生物 自由生长为单丝（连续的生长）或 聚集体，其中细胞的丝状组织是 不明显（aseriate生长）。 aseriate型细胞表达 对极端的水分胁迫有明显的耐受性， 大量的一类可溶性酸性蛋白质， 经受反复的干燥和再水化循环。 一 这些水分胁迫（Wsp）蛋白是糖蛋白，两个 其他的则与碳水化合物密切相关。 目标 该项目的目的是纯化和生物化学特性， 蛋白质和相关的碳水化合物，了解如何 蛋白质的合成受水分胁迫控制， 发现Wsp蛋白在脱水耐受性中的作用。 本研究中使用的技术涉及半连续和 发酵罐中细胞的同步生长、固定化和 细胞在惰性固体支持物上的生长，蛋白质纯化， 蛋白A-金免疫标记和固氮测定 包括检测受到水的细胞中的nifH mRNA 应力 关于事件的先后顺序没有达成共识， 导致水分胁迫抑制植物生长。 的 这项工作的目的是帮助我们了解 耐干燥性 因此，这项工作在 水资源短缺对环境的影响程度 管理农业的成功以及基本的 水在基因表达中的重要性

Nostoc commune is a nitrogen-fixing photosynthetic cyanobacterium with the capacity for desiccation-tolerance. This microorganism grows freely as single filaments (seriate growth) or in aggregates where filamentous organization of the cells is indistinct (aseriate growth). Cells of the aseriate type express a pronounced tolerance to extremes of water stress and accumulate massive amounts of a class of soluble acidic proteins when they are subjected to repeated cycles of drying and rehydration. One of these water stress (Wsp) proteins is a glycoprotein, two others are intimately associated with carbohydrate(s). The aims of this project are to purify and characterize biochemically the Wsp proteins and associated carbohydrates, understand how the synthesis of the proteins is controlled by water stress, and to discover the role of Wsp proteins in desiccation tolerance. Techniques used in this study involve semi-continuous and synchronized growth of cells in a fermenter, immobilization and growth of cells on inert solid supports, protein purification, protein A-gold immunolabelling, and assays for nitrogen fixation including the detection of nifH mRNA in cells subjected to water stress. There is no consensus of opinion on the sequence of events that leads to the suppression of plant growth by waterstress. The objective of this work is to contribute to our understanidng of desiccation tolerance. Consequently, the work is significant in view of the extent to which water deficits impinge upon the success of managed agriculture as well as the fundamental importance of water in gene expression.