Isolation And Expression Of PtlabA-like1 And PtPCP-like In Populus Tomentosa And Transformation In Tobacco And Poplar

Populus tomentosa Carr. (Chinese white poplar) is a kind of native species with high wood quality and fast-growing. However, its long period of breeding and flowering pollution have been bringing a lot of inconvenience to people's daily life. To understand the genetic and molecular mechanisms underlying floral development in Populus tomentosa, we isolated a labA-like gene and a PCP (pollen coat protein,PCP)-like gene from floral bud cDNA library of P. tomentosa, which we name PtlabA-like1 and PtPCP-like respectively, using bacteriophage absorption by filter paper-PCR method. Sequencing PtlabA-like1 showed an intact ORF-containing 1769 bp full sequence that encodes 411 amino acids, with length of 5'-and 3'-UTR being 259 bp and 277 bp respectively. Meanwhile, PtPCP-like has an intact ORF-containing 595 bp, full sequence that encodes 91 amino acids, with length of 5'-and 3'-UTR being 83 bp and 239 bp respectively. A conserved LabA-like superfamily domain was found via searching Conserved Domains Database. A phylogenetic tree of labA-like gene family was constructed to depict its evolutionary relationship with other 9 members comprising the same domain that retrieved via BLAST at JGI. The expression patterns of LabA-like superfamily members in tissues of P. tomentosa were estimated by RT-PCR. Our results revealed a diversity on expression pattern among these labA-like gene members. PtlabA-like1 and PtlabA-like6 have common expression domains at stems, young leaves, mature leaves, male and female flower buds, but a higher abundance was especially shown in PtlabA-like1. PtlabA-like8 was detected with a low level at root only. Other members which have different abundances have a constitutive expression pattern at all of the six tissues. A diversity on expression pattern among PtPCP-like was detected, too. The PtPCP-like gene has a common expression domain at roots, stems, young leaves, mature leaves and male flower buds, except female flower buds, but a higher abundance was especially shown in roots and male flower buds. And, constitutive expression vectors carrying 35S::PtlabA-like1 and 35S::PtPCP-like have been constructed. To study PtlabA-like1 gene and PtPCP-like gene further, vectors of 35S::PtlabA-like1 and 35S::PtPCP-like were transformed into Nicotiana tabacum and Populus tomentosa via Agrobacterium-mediated transformation method. The positive transgenic tobacco and poplar individuals were primarily verified by PCR. Moreover, poplar individuals were identified by RT-PCR method. All of these would provide the ground work for understanding the functions of PtlabA-like1 gene and PtPCP-like gene.