Expression profiling of C1 metabolic genes involved in monolignol biosynthesis (2007)

在植物细胞中，一些C1代谢基因在为各种化合物的合成提供甲基残基方面发挥着重要作用。我们试图确定C1代谢途径中哪些基因对木质素生物合成是重要的，其中应该需要大量的甲基残基。采用RT-PCR和虚拟Northern blot分析丝氨酸羟甲基转铁酶（SHMT）、甘氨酸脱羧酶、甲酰基THF合成酶、THF脱氢酶/环水解酶、亚甲基THF还原酶、蛋氨酸合成酶、蛋氨酸腺苷转移酶等基因的表达情况。在杨树中，其中一个SHMT基因在木质部组织中表达，木质部组织中木质素含量较高。在拟南芥中，shmt由7个不同的基因编码。首先，我们利用PT-PCR分析了各基因在拟南芥不同组织中的表达模式。结果表明，虽然7个基因中有6个在木质部组织中表达，但其中SHMT7 （At4g13930）的表达量最高。为了进行更深入的分析，我们分离了T-DNA插入SHMT基因之一（SHMT7, At4g13930）的拟南芥突变体，并对其表型进行了表征。突变体在土壤中培养后，在光镜下用茎组织切片分析了植物木质素的生物合成。分析结果表明，突变体木质部木质素含量略低于野生型。我们分析。这些数据表明，SHMT可能在木质素生物合成途径的甲基渣供应中发挥任何作用。

In plant cell, some C1 metabolic genes play important role in supply of methyl residues for synthesis of various types of compounds. We tried to identify which genes in the C1 metabolic pathway are important for lignin biosynthesis in which a lot of methyl residues should be needed. Expression of several genes, serine hydroxymethyltrans-ferase (SHMT), glycine decarboxylase, formyl THF synthetase, THF dehydrogenase/cyclohydrolase, Methylene THF reductase, Methionine synthetase, Methionine adenosyl-transferase, were analyzed by RT-PCR and virtual Northern blot analyses. In poplar plants, one of SHMT genes is expressed in xylem tissue which contains higher amount of lignin. In Arabidopsis, SHMTs were coded by seven different genes. At first, we analyzed expression pattern of each genes in various tissue of Arabidopsis plant by PT-PCR. As a result of the analysis, although six of the seven genes were expressed in xylem tissue, expression of SHMT7 (At4g13930) was highest among those of the genes analyzed. For more depth analysis, we isolated Arabidopsis mutant with T-DNA insertion into one of SHMT genes (SHMT7, At4g13930) and characterized phenotypes of it. After cultivation of the mutant in soil, lignin biosynthesis of the plant was analyzed under light microscopy with thin section of stem tissue. The results of the analysis suggest lignin content of xylem tissue in the mutant is slightly lower than that in wild-type plant. We analyzed. These data indicate that SHMT may play any role in supply of methyl residue to lignin biosynthetic pathway.