Laser microdissection-assisted analysis of ligninication and related gene expression in the microstructure of woody lignifiying cells

采用激光显微解剖（LMD）技术从木质素化的不同阶段或不同器官中收集细胞，进行木质素结构和基因表达分析。Real-time PCR分析木质素化相关基因的转录。COMT， CCoAOMT和CAD在木质素沉积前转录。CCR和4CL的转录水平低于它们。CCR代表木质化特定途径；因此，它被认为是木质素生物合成的调控基因。结合LMD和Py-GC/MS，仅以0.1平方毫米的最小样品即可实现木质素结构分析。结果表明，紫丁香基木质素是在木质素化初期合成的，即使在组织化学观察看来木质素化已经完成的区域，木质素化的结构变化仍在进行。

The cells were collected from the different stages of lignification or different organs by a laser micro-dissection (LMD) technique and were subjected to the analyses of lignin structure and gene expression.Transcriptions of the lignification related genes were analyzed by Real-time PCR. COMT, CCoAOMT, and CAD, were transcribed prior to lignin deposition. The transcription levels of CCR and 4CL were lower than them. CCR stands in the lignification specific pathway; therefore it is considered to be a regulatory gene in the lignin biosynthesis. The lignin structure analysis was achieved with only 0.1 square millimeter samples as a minimum requirement by the combined LMD and Py-GC/MS. The results indicated that syringyl lignin is synthesized in the beginning of lignification, and that structural changes of lignification still proceeds even in the area in which lignification seems already completed by the histochemical observations.