Molecular characterization of two Arabidopsis thaliana glycosyltransferase mutants, rra1 and rra2, which have a reduced residual arabinose content in a polymer tightly associated with the cellulosic wall residue
Molecular characterization of two Arabidopsis thaliana glycosyltransferase mutants, rra1 and rra2, which have a reduced residual arabinose content in a polymer tightly associated with the cellulosic wall residue
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DOI：
10.1007/s11103-007-9162-y
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发表时间：
2007-07-01
影响因子：
5.1
通讯作者：
Petersen, Bent Larsen
中科院分区：
文献类型：
--
作者：
Egelund, Jack;Obel, Nicolai;Petersen, Bent Larsen
在分子水平上研究了拟南芥中两种可能的糖基转移酶，分别命名为还原残留阿拉伯糖-1和-2(RRA1和RRA2)。这两个基因都被归入CAZy GT-77家族，并且与莱茵衣藻的糖基转移酶有亲缘关系。利用从拟南芥不同器官中提取的mRNA，用半定量RT-PCR方法分析了这两个基因的表达模式。此外，对含有RRA-1或-2启动子片段和GUSA报告基因融合的转基因拟南芥的启动子：：GUSA分析表明，RRA1启动子主要在顶端分生组织中活性，而RRA2启动子在分生区的表达模式更加多样化。此外，还从分子和生化水平对RRA-1和RRA-2的T-DNA突变体插入系进行了鉴定和鉴定。从分生区分离的细胞壁物质的单糖组成分析表明，酶法去除木葡聚糖和果胶多糖后，不溶性/未消化的细胞壁残留物中的阿拉伯糖含量减少了约20%。这些数据表明，RRA-1和-2都在细胞壁成分的阿拉伯糖基化中发挥作用(S)。
Two putative glycosyltransferases in Arabidopsis thatiana, designated reduced residual arabinose-1 and -2 (RRA1 and RRA2), are characterized at the molecular level. Both genes are classified in CAZy GT-family-77 and are phylogenetically related to putative glycosyltranferases of Chlaniydomonas reinhardtii. The expression pattern of the two genes was analyzed by semi-quantitative RT-PCR using mRNA extracted from various organs of bolting Arabidopsis thaliana plants. In addition, promoter::gusA analysis of transgenic Arabidopsis thaliana containing a fusion between either the RRA-1 or -2 promoter fragment and the gusA reporter gene showed that whereas the RRA1 promoter was primarily active in the apical meristem, the expression pattern of the RRA2 promoter was more diverse but also highly active in the meristematic region. In addition, T-DNA mutant insertion lines of both RRA-1 and -2, were identified and characterized at the molecular and biochemical level. Monosaccharide compositional analyses of cell wall material isolated from the meristematic region showed a ca. 20% reduction in the arabinose content in the insoluble/undigested cell wall residue after enzymatic removal of xyloglucan and pectic polysaccharides. These data indicate that both RRA-1 and -2 play a role in the arabinosylation of cell wall component(s).