Up-regulation of sucrose synthase and UDP-glucose pyrophosphorylase impacts plant growth and metabolism
Up-regulation of sucrose synthase and UDP-glucose pyrophosphorylase impacts plant growth and metabolism
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DOI：
10.1111/j.1467-7652.2005.00160.x
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发表时间：
2006-01-01
影响因子：
13.8
通讯作者：
Mansfield, SD
中科院分区：
文献类型：
--
作者：
Coleman, HD;Ellis, DD;Mansfield, SD
研究了过表达蔗糖合成酶(SUSY)和UDP-葡萄糖焦磷酸化酶(UGPase)对烟草植株生长和代谢的影响。Xanthi)。在花椰菜花叶病毒35S启动子(2x35S)或木质部定位的4CL启动子(4-香豆酸：CoA连接酶；4CL)的控制下，获得了表达这两种基因的T-1转基因植株。对茎组织的转录水平、酶活性、生长参数、纤维特性和碳水化合物含量进行了量化。两个基因的表达谱证实了启动子的表达模式：2x35S在叶片中表达较强，而4CL在茎组织中表达最高。深入的植株鉴定表明，与相应的对照品系相比，单基因转基因品系的株高生长有明显的提高。双转基因植株表现出加性效应，证明比单转基因亲本还要高。其中有几个品系与可溶性糖含量的增加有关。虽然没有观察到贮藏碳水化合物被分配到淀粉或纤维素中，但身高增长和可溶性碳水化合物的增加表明，Susy作为库容量的一个标记，并支持UGPase在类似作用中的作用。这两个基因的上调，虽然没有增加纤维素含量的百分比，但有效地增加了给定植物的总生物量，从而增加了总纤维素产量。
The effects of the overexpression of sucrose synthase (SuSy) and UDP-glucose pyrophosphorylase (UGPase) on plant growth and metabolism were evaluated in tobacco (Nicotiana tabacum cv. Xanthi). T-1 transgenic plants expressing either gene under the control of a tandem repeat cauliflower mosaic virus 35S promoter (2x35S) or a xylem-localized 4CL promoter (4-coumarate:CoA ligase; 4CL) were generated, and reciprocally crossed to generate plants expressing both genes. Transcript levels, enzyme activity, growth parameters, fibre properties and carbohydrate content of stem tissue were quantified. The expression profiles of both genes confirmed the expression pattern of the promoters: 2x35S expressed more strongly in leaves, while 4CL expression was highest in stem tissue. In-depth plant characterization revealed that the single-transgene lines showed significant increases in the height growth compared with corresponding control lines. The double-transgene plants demonstrated an additive effect, proving to be even taller than the single-transgene parents. Several of these lines had associated increases in soluble sugar content. Although partitioning of storage carbohydrates into starch or cellulose was not observed, the increased height growth and increases in soluble carbohydrates suggest a role for SuSy as a marker in sink strength and lend credit to the function of UGPase in a similar role. The up-regulation of these two genes, although not increasing the percentage cellulose content, was effective in increasing the total biomass, and thus the overall cellulose yield, from a given plant.