title: The Eucalyptus Tonoplast Intrinsic Protein (TIP) Gene Subfamily: Genomic Organization, Structural Features, and Expression Profiles.
abstract: Plant aquaporins are water channels implicated in various physiological processes, including growth, development and adaptation to stress. In this study, the Tonoplast Intrinsic Protein (TIP) gene subfamily of Eucalyptus, an economically important woody species, was investigated and characterized. A genome-wide survey of theEucalyptus grandisgenome revealed the presence of eleven putative TIP genes (referred asEgTIP), which were individually assigned by phylogeny to each of the classical TIP1-5 groups. Homology modeling confirmed the presence of the two highly conserved NPA (Asn-Pro-Ala) motifs in the identified EgTIPs. Residue variations in the corresponding selectivity filters, that might reflect differences in EgTIP substrate specificity, were observed. AllEgTIPgenes, exceptEgTIP5.1, were transcribed and the majority of them showed organ/tissue-enriched expression. Inspection of theEgTIPpromoters revealed the presence of commoncis-regulatory elements implicated in abiotic stress and hormone responses pointing to an involvement of the identified genes in abiotic stress responses. In line with these observations, additional gene expression profiling demonstrated increased expression under polyethylene glycol-imposed osmotic stress. Overall, the results obtained suggest that these novelEgTIPsmight be functionally implicated in eucalyptus adaptation to stress.
authors.affiliation: Department of Genetics, Institute of Biosciences of Botucatu, São Paulo State University Botucatu, Brazil.
authors.forename: Marcela I
authors.initials: MI
authors.lastname: Rodrigues
authors.affiliation: Department of Physics and Biophysics, Institute of Biosciences of Botucatu, São Paulo State UniversityBotucatu, Brazil; Institute of Biotechnology, São Paulo State UniversityBotucatu, Brazil.
authors.forename: Agnes A S
authors.initials: AA
authors.lastname: Takeda
authors.affiliation: Department of Genetics, Institute of Biosciences of Botucatu, São Paulo State University Botucatu, Brazil.
authors.forename: Juliana P
authors.initials: JP
authors.lastname: Bravo
authors.affiliation: Department of Genetics, Institute of Biosciences of Botucatu, São Paulo State University Botucatu, Brazil.
authors.forename: Ivan G
authors.initials: IG
authors.lastname: Maia
keywords: Eucalyptus; abiotic stress; aquaporin; gene expression; gene structure; tonoplast intrinsic protein