The natural rubber of Para rubber tree, Hevea brasiliensis, is the main crop involved
in industrial rubber production due to its superior quality. The Hevea bark is commercially
exploited to obtain latex, which is produced from the articulated secondary laticifer.
The laticifer is well defined in the aspect of morphology; however, only some genes
associated with its development have been reported. We successfully induced secondary
laticifer in the jasmonic acid (JA)-treated and linolenic acid (LA)-treated Hevea
bark but secondary laticifer is not observed in the ethephon (ET)-treated and untreated
Hevea bark. In this study, we analysed 27,195 gene models using NimbleGen microarrays
based on the Hevea draft genome. 491 filtered differentially expressed (FDE) transcripts
that are common to both JA- and LA-treated bark samples but not ET-treated bark samples
were identified. In the Eukaryotic Orthologous Group (KOG) analysis, 491 FDE transcripts
belong to different functional categories that reflect the diverse processes and pathways
involved in laticifer differentiation. In the Kyoto Encyclopedia of Genes and Genomes
(KEGG) and KOG analysis, the profile of the FDE transcripts suggest that JA- and LA-treated
bark samples have a sufficient molecular basis for secondary laticifer differentiation,
especially regarding secondary metabolites metabolism. FDE genes in this category
are from the cytochrome (CYP) P450 family, ATP-binding cassette (ABC) transporter
family, short-chain dehydrogenase/reductase (SDR) family, or cinnamyl alcohol dehydrogenase
(CAD) family. The data includes many genes involved in cell division, cell wall synthesis,
and cell differentiation. The most abundant transcript in FDE list was SDR65C, reflecting
its importance in laticifer differentiation. Using the Basic Local Alignment Search
Tool (BLAST) as part of annotation and functional prediction, several characterised
as well as uncharacterized transcription factors and genes were found in the dataset.
Hence, the further characterization of these genes is necessary to unveil their role
in laticifer differentiation. This study provides a platform for the further characterization
and identification of the key genes involved in secondary laticifer differentiation.