Transcript Accumulation Dynamics of Phenylpropanoid Pathway Genes in the Maturing Xylem and Phloem of Picea abies during Latewood Formation  

作　　者：Giovanni Emiliani Maria Laura Traversi Monica Anichini Guido Giachi Alessio Giovannelli 

机构地区：[1]Trees and Timber Institute-National Research Council [2]Department of Chemistry "U.Schiff",University of Florence

出　　处：《Journal of Integrative Plant Biology》2011年第10期783-799,共17页植物学报（英文版）

基　　金：supported by the project SOFIE-2(Reg.Delib.No.3012-2007);funded by the Provincia Autonoma di Trento,Italy

摘　　要：In temperate regions, latewood is produced when cambial activity declines with the approach of autumnal dormancy. The understanding of the temporal （cambium activity vs dormancy） and spatial （phloem, cambial region, maturing xylem） regulation of key genes involved in the phenylpropanoid pathway during latewood formation represents a crucial step towards providing new insights into the molecular basis of xylogenesis. In this study, the temporal pattern of transcript accumulation of 12 phenylpropanoid genes （PAL1, C4H315, C4H4, 4CL3, 4CL4, HCT1, C3H3, CCoAOMT1, COMT2, COMT5, CCR2） was analyzed in maturing xylem and phloem of Picea abies during latewood formation. Quantitative reverse transcription-polymerase chain reaction analyses revealed a well-defined RNA accumulation pattern of genes involved in the phenylpropanoid pathway during latewood formation. Differences in the RNA accumulation patterns were detected between the different tissue types analyzed. The results obtained here demonstrated that the molecular processes involved in monolignol biosynthesis are not restricted to the cambial activity timeframe but continued after the end of cambium cell proliferation. Furthermore, since it has been shown that lignification of maturing xylem takes place in late autumn, we argue on the basis of our data that phloem could play a key role in the monoliqnol biosynthesis process.In temperate regions, latewood is produced when cambial activity declines with the approach of autumnal dormancy. The understanding of the temporal （cambium activity vs dormancy） and spatial （phloem, cambial region, maturing xylem） regulation of key genes involved in the phenylpropanoid pathway during latewood formation represents a crucial step towards providing new insights into the molecular basis of xylogenesis. In this study, the temporal pattern of transcript accumulation of 12 phenylpropanoid genes （PAL1, C4H315, C4H4, 4CL3, 4CL4, HCT1, C3H3, CCoAOMT1, COMT2, COMT5, CCR2） was analyzed in maturing xylem and phloem of Picea abies during latewood formation. Quantitative reverse transcription-polymerase chain reaction analyses revealed a well-defined RNA accumulation pattern of genes involved in the phenylpropanoid pathway during latewood formation. Differences in the RNA accumulation patterns were detected between the different tissue types analyzed. The results obtained here demonstrated that the molecular processes involved in monolignol biosynthesis are not restricted to the cambial activity timeframe but continued after the end of cambium cell proliferation. Furthermore, since it has been shown that lignification of maturing xylem takes place in late autumn, we argue on the basis of our data that phloem could play a key role in the monoliqnol biosynthesis process.

关 键 词：cambial region gene expression latewood formation xylogenesis. 

分 类 号：S791.18[农业科学—林木遗传育种]