Abstract:

Previous studies revealed some anatomic and physiological mechanism about bamboo shoot development.But little is known about the molecular mechanism of shoot branching during bamboo shoot development.The studies on shoot branching related genes would therefore be helpful to elucidate the molecular mechanism.In this paper a 1 296 bp cDNA sequence was cloned from bamboo shoot of Phyllostachys violascens by RT-PCR method with degenerated primers based on the sequence conservation of Poaceae TB1 homologous genes.It has an open reading frame encoding 349 amino acids which has 64.7% identity with maize TB1 and thus is named PpTB1.Sequence alignment indicates that PpTB1 contains SP,TCP and R domain which are main characteristics of TB1 homologs in TCP protein family.Phylogeny analysis indicates that the divergence time of bamboo TB1 homologs are later than rice OsTB1 but earlier than other Poaceae TB1 homologs.Taken together,these TB1-like sequences are probably the TB1 homologous genes in bamboo.Although RT-PCR indicates that PpTB1 expression can be detected in leaf,bamboo shoot and young floret,the in situ hybridization reveals that the gene is highly expressed in axillary bud of bamboo shoot.Thus,PpTB1 may have similar function with its counterpart in grass and has the potential to regulate the production of bamboo shoot.In addition,TB1 homologous genes may also be valuable on the studies of bamboo taxonomy and evolution.

Key words: Phyllostachys violascens, bamboo shoot development, TB1 homologous genes