Immunolocalization of two lignin O-methyltransferases in stems of alfalfa (Medicago sativa L.)
Immunolocalization of two lignin O-methyltransferases in stems of alfalfa (Medicago sativa L.)
复制标题
DOI：
10.1007/bf01415700
复制
发表时间：
1999-01-01
期刊：
影响因子：
2.9
通讯作者：
Dixon, RA
中科院分区：
文献类型：
--
作者：
Kersey, R;Inoue, K;Dixon, RA
咖啡酸3-O-甲基转移酶（COMT）和咖啡酰CoA 3-O-甲基转移酶（CCOMT）催化被认为参与木质素单体生物合成的平行反应。苜蓿（Medicago sativa L.）COMT或CCOMT是针对大肠杆菌中表达的酶提出的，并用于在木质化苜蓿茎组织中的免疫定位研究。COMT和CCOMT定位于木质部薄壁细胞，通过光学显微镜和免疫细胞化学进行评估。电子显微镜观察发现，这两种酶都定位于木质部薄壁细胞的细胞质中，韧皮部细胞的细胞质中也有少量酶。COMT和CCOMT的定位模式没有显著差异，表明这两种酶可能是导致成熟苜蓿茎节间木质化组织中木质素单体产生的代谢网格的一部分。
Caffeic acid 3-O-methyltransferase (COMT) and caffeoyl CoA 3-O-methyltransferase (CCOMT) catalyze parallel reactions that are believed to be involved in the biosynthesis of lignin monomers. Antisera specific for alfalfa (Medicago sativa L.) COMT or CCOMT were raised against the enzymes expressed in Escherichia coli, and were used for immunolocalization studies in lignifying alfalfa stem tissue. Both COMT and CCOMT were localized to xylem parenchyma cells, as assessed by light microscopy and immunocytochemistry. Electron microscopy revealed that both enzymes were located in the cytoplasm of xylem parenchyma cells, and to a lesser er;tent, in the cytoplasm of phloem cells. There was no significant difference in the localization pattern of COMT and CCOMT, suggesting that the two enzymes may be part of a metabolic grid leading to production of Lignin monomers in lignifying tissue of mature alfalfa stem internodes.