Cloning and expression analysis of TcAPLs in Taxus chinensis / 中草药

ABSTRACT

Objective: To clone altered phloem development (APL) genes from Taxus chinensis and reveal their potential regulatory role in tissues regeneration after bark girdling by investigating the expression profiles of these APLs. Methods: The full-length three APL genes were isolated using reverse transcription-polymerase chain reaction (RT-PCR) and were named as TcAPL1, TcAPL2, and TcAPL3, respectively. The expression profiles of these genes in different tissues and at different regeneration stages after bark girdling were analyzed by semi-quantitative RT-PCR and quantitative real-time PCR (qRT-PCR), respectively. Results: Phylogenetic tree analysis suggested that TcAPL1 and TcAPL2 could be clustered together with APL protein of Morus notabilis, which are closest in genetic relationship; TcAPL3 could be clustered with APL proteins of another big independent branch. The analysis of gene expression patterns in different tissues showed that the transcript abundances of TcAPL1 and TcAPL2 were mainly expressed in the roots, stems, leaves, and phloem with cambium; While TcAPL3 was higher in the leaves than that in the roots and xylem with cambium. Through analysis of the expression patterns in regeneration tissues after bark girdling, the mRNA expressions of TcAPL1 and TcAPL2 showed a up-down trend in the following periods and were found to decrease notably at 36 d after bark girdling, while the expression of TcAPL3 was repressed at all stages after bark girdling. Conclusion: In this study, three TcAPLs genes are cloned from T. chinensis, and their expressions are regulated in the regeneration processes after bark girdling. Our results demonstrate that APL might play a regulatory role in tissue regeneration after bark girdling in T. chinensis.