Over-expression of specific HvCslF cellulose synthase-like genes in transgenic barley increases the levels of cell wall (1,3;1,4)-β-D-glucans and alters their fine structure
Over-expression of specific HvCslF cellulose synthase-like genes in transgenic barley increases the levels of cell wall (1,3;1,4)-β-D-glucans and alters their fine structure
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DOI：
10.1111/j.1467-7652.2010.00532.x
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发表时间：
2011-02-01
影响因子：
13.8
通讯作者：
Fincher, Geoffrey B.
中科院分区：
文献类型：
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作者：
Burton, Rachel A.;Collins, Helen M.;Fincher, Geoffrey B.
在商业上重要的谷物和草的细胞壁的特征是存在（1，3; 1，4）-β-D-葡聚糖。这些多糖是人类饮食的有益成分，它们可以降低高胆固醇血症、II型糖尿病、肥胖和结肠直肠癌的风险。禾本科中细胞壁（1，3; 1，4）-β-d-葡聚糖的生物合成至少部分地由纤维素酶样CslF基因家族介导。在胚乳特异性燕麦球蛋白启动子控制下的大麦CslF 6基因的过表达导致转基因大麦的谷粒中（1，3; 1，4）-β-d-葡聚糖含量增加超过80%。分析（1，3; 1，4）-β-d-葡聚糖精细结构表明，单独的CslF酶可能指导具有不同结构的（1，3; 1，4）-β-d-葡聚糖的合成。当CslF 6转基因的表达由Pro35 S启动子驱动时，转基因株系在叶中具有高达六倍的（1，3; 1，4）-β-d-葡聚糖水平，但在谷粒中具有与对照相似的水平。Pro35 S：CslF 4的一些转基因品系还显示出谷粒中（1，3; 1，4）-β-d-葡聚糖的水平增加，但叶中没有。因此，CslF基因对（1，3; 1，4）-β-d-葡聚糖水平的影响不仅取决于所用的启动子，而且取决于插入到转基因大麦品系中的CslF基因家族的特定成员。改变（1，3;谷物和营养组织中的（1，3; 1，4）-β-D-葡聚糖水平将在人类健康中具有潜在的应用，其中（1，3; 1，4）-β-D-葡聚糖有助于膳食纤维，并且在定制生物质细胞壁的组成以用于从谷类作物残留物和草生产生物乙醇中具有潜在的应用。
P>Cell walls in commercially important cereals and grasses are characterized by the presence of (1,3;1,4)-beta-d-glucans. These polysaccharides are beneficial constituents of human diets, where they can reduce the risk of hypercholesterolemia, type II diabetes, obesity and colorectal cancer. The biosynthesis of cell wall (1,3;1,4)-beta-d-glucans in the Poaceae is mediated, in part at least, by the cellulose synthase-like CslF family of genes. Over-expression of the barley CslF6 gene under the control of an endosperm-specific oat globulin promoter results in increases of more than 80% in (1,3;1,4)-beta-d-glucan content in grain of transgenic barley. Analyses of (1,3;1,4)-beta-d-glucan fine structure indicate that individual CslF enzymes might direct the synthesis of (1,3;1,4)-beta-d-glucans with different structures. When expression of the CslF6 transgene is driven by the Pro35S promoter, the transgenic lines have up to sixfold higher levels of (1,3;1,4)-beta-d-glucan in leaves, but similar levels as controls in the grain. Some transgenic lines of Pro35S:CslF4 also show increased levels of (1,3;1,4)-beta-d-glucans in grain, but not in leaves. Thus, the effects of CslF genes on (1,3;1,4)-beta-d-glucan levels are dependent not only on the promoter used, but also on the specific member of the CslF gene family that is inserted into the transgenic barley lines. Altering (1,3;1,4)-beta-d-glucan levels in grain and vegetative tissues will have potential applications in human health, where (1,3;1,4)-beta-d-glucans contribute to dietary fibre, and in tailoring the composition of biomass cell walls for the production of bioethanol from cereal crop residues and grasses.