Brown David M, Zeef Leo A H, Ellis Joanne, Goodacre Royston, Turner Simon R
Faculty of Life Science, University of Manchester, Manchester M13 9PT United Kingdom.
Plant Cell. 2005 Aug;17(8):2281-95. doi: 10.1105/tpc.105.031542. Epub 2005 Jun 24.
Forward genetic screens have led to the isolation of several genes involved in secondary cell wall formation. A variety of evidence, however, suggests that the list of genes identified is not exhaustive. To address this problem, microarray data have been generated from tissue undergoing secondary cell wall formation and used to identify genes that exhibit a similar expression pattern to the secondary cell wall-specific cellulose synthase genes IRREGULAR XYLEM1 (IRX1) and IRX3. Cross-referencing this analysis with publicly available microarray data resulted in the selection of 16 genes for reverse genetic analysis. Lines containing an insertion in seven of these genes exhibited a clear irx phenotype characteristic of a secondary cell wall defect. Only one line, containing an insertion in a member of the COBRA gene family, exhibited a large decrease in cellulose content. Five of the genes identified as being essential for secondary cell wall biosynthesis have not been previously characterized. These genes are likely to define entirely novel processes in secondary cell wall formation and illustrate the success of combining expression data with reverse genetics to address gene function.
正向遗传学筛选已导致多个参与次生细胞壁形成的基因被分离出来。然而，各种证据表明，已鉴定出的基因列表并不详尽。为了解决这个问题，已从经历次生细胞壁形成的组织中生成了微阵列数据，并用于鉴定与次生细胞壁特异性纤维素合酶基因不规则木质部1（IRX1）和IRX3表现出相似表达模式的基因。将该分析与公开可用的微阵列数据进行交叉引用，从而选择了16个基因进行反向遗传学分析。在其中7个基因中含有插入突变的株系表现出次生细胞壁缺陷的明显irx表型特征。只有一个株系，其COBRA基因家族成员中含有插入突变，纤维素含量大幅下降。已确定对次生细胞壁生物合成至关重要的5个基因此前尚未被表征。这些基因可能定义了次生细胞壁形成中全新的过程，并说明了将表达数据与反向遗传学相结合以研究基因功能的成功之处。
