Molecular study on usage of unused available resources from northern trees

北方树木未利用资源的分子研究

基本信息

批准号：
14360093
负责人：
FUJIKAWA Seizo
金额：
$ 9.41万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

We studied freezing adaptation mechanisms of northern trees including the cortical and xylem parenchyma cells at molecular level.Cortical parenchyma cells of the northern trees adapt to subfreezing temperatures by extracellular freezing. These cells can adapt freezing even to liquid nitrogen temperature by obtaining high tolerance to freezing-induced dehydration. We identified that group 3 LEA proteins were specifically accumulated in ER of the cortical parenchyma cells of mulberry during winter. We named this protein as WAP27 and examined the function both in planta and in vitro. Transgenic Arabidopsis plants introduced WAP27 obtained higher freezing tolerance after cold acclimation as compared with wild type plants. Furthermore, purified WAP27 had cryoprotective activity to freezing sensitive proteins, such as LDH.Xylem parenchyma cells of trees, on the other hand, adapt to subfreezing temperatures by deep supercooling. The xylem parenchyma cells from northern trees can supercool -60 … More C. In order to examine mechanisms that water keep supercooling in xylem parenchyma cells, we analyzed gene expression, accumulation of proteins and soluble sugars. With comprehensive gene analysis about xylem of Larch, we could find several genes that were never reported as cold-induced genes in plants. We confirmed by northern blot analysis hat these genes were expressed in parallel with increased supercooling ability. On protein analysis using beech, we could identified a few tens protein-spots that were specifically accumulated in parallel with increased supercooling ability. Among these proteins, we purified chitinase-like proteins, which are known as one of antifreezing proteins in plants, and antifreeze activity was examined with negative result. We also analyzed soluble proteins in xylem of birch. However, the accumulation was same with the cortical parenchyma cells that adapt to subfreezing temperature by extracellular freezing. Finally, we obtained crude extracts from xylem (parenchyma cells) and the effect to supercooling of water was examined. We could find that the crude extracts from xylem that exhibited high supercooling in the parenchyma cells provided high ability of supercooling to water. Now, we are continuing identifications of substances within crude extracts that may provide high supercooling.Our results showed that winter-induced genes and gene products from northern trees that exhibit extraordinary high freezing resistance may be useful resources for developing crops with high freezing resistance as well as for the use of them for freezing regulate substances in wide range of industries. Less

我们研究了北树的冻结适应机制，包括分子水平的皮质和木质部实质细胞。这些细胞可以通过获得对冰冻诱导的脱水的高耐受性，甚至可以使冷冻温度适应液体氮温度。我们发现，冬季，第3组LEA蛋白是特异性积聚在Mulberry的皮质实质细胞中的ER。我们将此蛋白命名为WAP27，并在植物和体外检查了该功能。与野生型植物相比，转基因拟南芥植物引入了WAP27在冷适应后获得更高的冷冻耐受性。此外，纯化的WAP27具有冷冻敏感蛋白质的冷冻保护活性，例如LDH。树木的Xylem实质细胞，另一方面，通过深层冷却来适应亚冻结温度。北部树木的木质部实质细胞可以超冷-60…更多C。通过有关落叶丘的木质部的全面基因分析，我们可以找到几种从未被报道为植物中冷诱导基因的基因。我们通过Northern印迹分析确认这些基因与超冷能力的提高表达。在使用山毛榉的蛋白质分析上，我们可以鉴定出一些特异性与超冷能力并行积累的蛋白质斑点。在这些蛋白质中，我们纯化了几丁质酶样蛋白质，这些蛋白被称为植物中的抗冻蛋白之一，并检查了抗冻活性，结果为阴性。我们还分析了桦木木质部中的固体蛋白。但是，通过细胞外冷冻适应亚冻结温度的皮质副群细胞的积累相同。最后，我们从木质部（实质细胞）中获得了粗提取物，并检查了水对水的影响。我们可以发现，木质部的粗提取物在副群细胞中暴露了高过冷的，提供了高冷水到水的能力。现在，我们正在继续对可能提供高过冷的原油提取物中的物质进行识别。我们的结果表明，来自北方树木的冬季引起的基因和基因产物暴露了非凡的高冰冻耐药性可能是开发具有高冷冻耐药性的农作物的有用资源，以及用于冻结其在广泛工业范围内的冰冻调节物质。较少的