This study reported the isolation and in silico characterization of fulllength cellulose synthase (CesA) cDNA from Neolamarckia cadamba, an important tropical plantation tree species. CesA is a member of processive glycosyltransferases that involved in cellulose biosynthesis of plants. CesA acts as a central catalyst in the generation of plant cell wall biomass or cellulose. It also plays an important role in regulating wood formation. The hypothetical full-length CesA cDNA (NcCesA1; JX134621) was assembled by contig mapping approach using the CesA cDNA sequences from NcdbEST and the amplified 5'-and 3'-RACE PCR sequences. The NcCesA1 cDNA has a length of 3,472 bp with 3,126 bp open reading frame encoding a 1,042 amino acid sequence. The predicted NcCesA1 protein contained N-terminal cysteine rich zinc binding domain, 7 putative Transmembrane Helices (TMH), 4 Umotifs that contain a signature D, D, D, QxxRW motif, an alternating Conserved Region (CR-P) and 2 Hypervariable Regions (HVR). These entire shared domain structures suggest the functional role of NcCesA1 is involved in glycosyltransferation of the secondary cell wall cellulose biosynthesis of N. cadamba. Sequence comparison also revealed the high similarity (90%) among NcCesA1 and PtrCesA2 of Populus tremuloides. This further implies the involvement of NcCesA1 that catalyzes the cellulose biosynthesis of secondary cell wall rather than primary cell wall. This full-length NcCesA1 cDNA can serve as good candidate gene in association genetics study which leads to Gene-Assisted Selection (GAS) in the N. cadamba tree breeding programme. Furthermore, the isolation of new CesA genes from tropical tree genomes is essential for enhancing knowledge of cellulose biosynthesis in trees that has many fundamental and commercial implications.

This study reported the isolation and in silico characterization of a full-length Xyloglucan endotransglycosylase/Hydrolase (XTH) cDNA from Neolamarckia cadamba, an important tropical light hardwood plantation tree species. XTH is considered as a key agent to regulate cell wall expansion and is believed to be responsible for the incorporation of newly synthesised xyloglucan into the wall matrix. The full-length of NcXTH was firstly predicted using the XTH singletons from the NcdbEST through contig mapping approach. Further validation and confirmation were conducted by amplifying the full-length XTH cDNA using RT-PCR approach. Two fulllength XTH cDNAs, namely NcXTH1 (JX134619) and NcXTH2 (JX134620) were discovered and the nucleotide sequences were 893 and 1,024 bp in length, respectively. The open reading frames for NcXTH1 and NcXTH2 were 858 and 915 bp, respectively. Results predicted that NcXTH1 and NcXTH2 proteins carry out XET activity but they are from different XTH family members. This full-length NcXTH cDNA can serve as good candidate genes in association genetics study which leads to Gene-Assisted Selection (GAS) in the N. cadamba tree breeding programme.