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

采用激光显微切割（LMD）技术从不同木质化阶段或不同器官中采集细胞，分析木质素结构和基因表达，并采用Real-time PCR技术分析木质化相关基因的转录。COMT、CCoAOMT和CAD在木质素沉积之前转录。CCR和4CL的转录水平较低。CCR基因位于木质化特异性途径中，因此被认为是木质素生物合成的调控基因。木质素结构的分析，实现了只有0.1平方毫米的样品作为最低要求的LMD和Py-GC/MS相结合。结果表明，在木质化的开始，合成的木质素，木质化的结构变化仍然进行，即使在该地区的木质化似乎已经完成了组织化学观察。

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.