Characterization of PTM5 in aspen trees: a MADS-box gene expressed during woody vascular development.
The vascular component of trees possesses some of the most specialized processes active in the formation of roots, stems, and branches, and its wood component continues to be of primary importance to our daily lives. The molecular mechanisms of wood development, however, remain poorly understood with few well-characterized regulatory genes. We have identified a vascular tissue-specific MADS-box gene, Populus tremuloides MADS-box 5 (PTM5) that is expressed in differentiating primary and secondary xylem and phloem. Phylogenetic analysis has shown that PTM5 is a member of the SOC1/TM3 class of MADS-box genes. Temporal expression analysis of PTM5 in staged vascular cambium and other tissues indicated that PTM5 expression is seasonal and is limited to spring wood formation and rapidly expanding floral catkins. Spatial expression analysis using in situ hybridization revealed that PTM5 expression is localized within a few layers of differentiating vascular cambium and xylem tissues as well as the vascular bundles of expanding catkins. Since many MADS-box genes are known to act as transcription factors, these results suggest that the coordinated expression of PTM5 with other vascular developmental genes may be a hallmark of the complex events that lead to the formation of the woody plant body.
Department of Biological Sciences, The University of Alabama in Huntsville, 142 Wilson Hall, Huntsville, AL 35899, USA.
Leland J
LJ
Cseke
Jun
J
Zheng
Gopi K
GK
Podila
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D026161:MADS Domain Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018514:Plant Structures / Q000235:genetics / Q000254:growth & development; D032107:Populus / Q000235:genetics* / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012621:Seasons; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014934:Wood
D018076:DNA, Complementary; D026161:MADS Domain Proteins; D010940:Plant Proteins; D012333:RNA, Messenger