Comparative transcriptome analysis of latex from rubber tree clone CATAS8-79 and PR107

Rubber tree (Hevea brasiliensis Muell. Arg.) is the primary commercial source of natural rubber in the world. Latex regeneration and duration of latex flow after tapping are the two factors that determine the rubber yield of a rubber tree, and exhibit a huge variation between rubber tree clones CATAS8-79 and PR107. In the present paper, with the purpose of globally characterizing latex transcriptome, RNAs were extracted from CATAS8-79 and PR107 at first tapping and sequenced with Illumina paired-end sequencing technology individually. After excluding low-quality reads as empty adapters, 26 million clean reads were generated in both pools. Using SOAPdenove software, 296,736 and 308,262 contigs ranging from 100 bp to more than 3000 bp were assembled in CATAS8-79 and PR107 (NCBI accession numbers: GSE59981). Based on paired-end and gap-filling, 53,571 and 57,806 unigenes were generated in CATAS8-79 and PR107 individually. With the help of unigenes from two pools, it is possible to identify the longer sequence derived from the same transcript as reference transcriptome. Thus, 51,829 all-unigenes were finally integrated using paired-end joining with an average length of 640 bp and a N50 of 526 bp.