title: Leaf-, panel- and latex-expressed sequenced tags from the rubber tree (Hevea brasiliensis) under cold-stressed and suboptimal growing conditions: the development of gene-targeted functional markers for stress response.
abstract: Hevea brasiliensisis a native species of the Amazon Basin of South America and the primary source of natural rubber worldwide. Due to the occurrence of South American Leaf Blight disease in this area, rubber plantations have been extended to suboptimal regions. Rubber tree breeding is time-consuming and expensive, but molecular markers can serve as a tool for early evaluation, thus reducing time and costs. In this work, we constructed six different cDNA libraries with the aim of developing gene-targeted molecular markers for the rubber tree. A total of 8,263 reads were assembled, generating 5,025 unigenes that were analyzed; 912 expressed sequence tags (ESTs) represented new transcripts, and two sequences were highly up-regulated by cold stress. These unigenes were scanned for microsatellite (SSR) regions and single nucleotide polymorphisms (SNPs). In total, 169 novel EST-SSR markers were developed; 138 loci were polymorphic in the rubber tree, and 98 % presented transferability to six otherHeveaspecies. Locus duplication was observed inH. brasiliensisand other species. Additionally, 43 SNP markers in 13 sequences that showed similarity to proteins involved in stress response, latex biosynthesis and developmental processes were characterized. cDNA libraries are a rich source of SSR and SNP markers and enable the identification of new transcripts. The new markers developed here will be a valuable resource for linkage mapping, QTL identification and other studies in the rubber tree and can also be used to evaluate the genetic variability of otherHeveaspecies, which are valuable assets in rubber tree breeding.
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP CEP 13083-970 Brazil.
authors.forename: Carla C
authors.initials: CC
authors.lastname: Silva
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP CEP 13083-970 Brazil.
authors.forename: Camila C
authors.initials: CC
authors.lastname: Mantello
authors.affiliation: Centro de Pesquisa Agroflorestal do Acre (CPAFAC), Embrapa, Rodovia BR-364, km 14, CP 321, Rio Branco, AC CEP 69900-970 Brazil.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Campos
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP CEP 13083-970 Brazil.
authors.forename: Livia M
authors.initials: LM
authors.lastname: Souza
authors.affiliation: Instituto Agronômico de Campinas (IAC), CP 28, Campinas, SP CEP 13012-970 Brazil.
authors.forename: Paulo S
authors.initials: PS
authors.lastname: Gonçalves
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6010, Campinas, SP CEP 13083-970 Brazil ; Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, CP 6109, Campinas, SP CEP 13083-970 Brazil.
authors.forename: Anete P
authors.initials: AP
authors.lastname: Souza
keywords: Hevea; Microsatellite; Molecular markers; Rubber tree; SNPs; cDNA library