title: Transcript Accumulation Dynamics of Phenylpropanoid Pathway Genes in the Maturing Xylem and Phloem of Picea abies during Latewood Formation.
abstract: 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, C4H3/5, 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 monolignol biosynthesis process.
authors.affiliation: Trees and Timber Institute-National Research Council, I-50019 Sesto Fiorentino, ItalyDepartment of Chemistry "U. Schiff", University of Florence, I-50019 Sesto Fiorentino, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Emiliani
authors.affiliation: Trees and Timber Institute-National Research Council, I-50019 Sesto Fiorentino, ItalyDepartment of Chemistry "U. Schiff", University of Florence, I-50019 Sesto Fiorentino, Italy.
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Traversi
authors.affiliation: Trees and Timber Institute-National Research Council, I-50019 Sesto Fiorentino, ItalyDepartment of Chemistry "U. Schiff", University of Florence, I-50019 Sesto Fiorentino, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Anichini
authors.affiliation: Trees and Timber Institute-National Research Council, I-50019 Sesto Fiorentino, ItalyDepartment of Chemistry "U. Schiff", University of Florence, I-50019 Sesto Fiorentino, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Giachi
authors.affiliation: Trees and Timber Institute-National Research Council, I-50019 Sesto Fiorentino, ItalyDepartment of Chemistry "U. Schiff", University of Florence, I-50019 Sesto Fiorentino, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Giovannelli
mesh_terms: D058506:Cambium / Q000235:genetics / Q000254:growth & development; D002482:Cellulose / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D008031:Lignin / Q000378:metabolism; D052585:Phloem / Q000235:genetics*; D028222:Picea / Q000235:genetics* / Q000254:growth & development*; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D020005:Propanols / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*; D012015:Reference Standards; D014934:Wood / Q000235:genetics / Q000254:growth & development*; D052584:Xylem / Q000235:genetics*
chemical_list: D020005:Propanols; D012333:RNA, Messenger; D018749:RNA, Plant; C439395:1-phenylpropanol; D002482:Cellulose; D008031:Lignin