title: Changes in gene expression profiles as they relate to the adult plant leaf rust resistance in the wheat cv. Toropi.
abstract: Leaf rust, caused by the foliar pathogenPuccinia triticinais a major disease of wheat in the southern region of Brazil and invariably impacts on production, being responsible for high yield losses. The Brazilian wheat cultivar Toropi has proven, durable adult plant resistance (APR) to leaf rust, which uniquely shows a pre-haustorial resistance phenotype. In this study we aimed to understand the interaction betweenP. triticinaand the pre-haustorial APR in Toropi by quantitatively evaluating the temporal transcription profiles of selected genes known to be related to infection and defense in wheat. The expression profiles of 15 selected genes varied over time, grouping into six expression profile groups. The expression profiles indicated the induction of classical defence pathways in response to pathogen development, but also the potential modification of Toropi's cellular status for the benefit of the pathogen. Classical defence genes, including peroxidases, β-1,3-glucanases and an endochitinase were expressed both early (pre-haustorial) and late (post-haustorial) over the 72 h infection time course, while induction of transcription of other infection-related genes with a potential role in defence, although variable was maintained through-out. These genes directly or indirectly had a role in plant lignification, oxidative stress, the regulation of energy supply, water and lipid transport, and cell cycle regulation. The early induction of transcription of defence-related genes supports the pre-haustorial resistance phenotype in Toropi, providing a valuable source of genes controlling leaf rust resistance for wheat breeding.
authors.affiliation: Agronomy Post-Graduate Program, University of Passo Fundo, BR285, Passo Fundo, Rio Grande do Sul 99052900, Brazil.
authors.forename: Alice
authors.initials: A
authors.lastname: Casassola
authors.affiliation: Department of Biotechnology and Phytophatology, Brazilian Agricultural Research Corporation, BR285, Km294, Passo Fundo, Rio Grande do Sul 99001970, Brazil.
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Brammer
authors.affiliation: Department of Biotechnology and Phytophatology, Brazilian Agricultural Research Corporation, BR285, Km294, Passo Fundo, Rio Grande do Sul 99001970, Brazil.
authors.forename: Márcia S
authors.initials: MS
authors.lastname: Chaves
authors.affiliation: Department of Fitossanidade, Federal University of Rio Grande do Sul, Avenida Bento Gonçalves 7712, Porto Alegre, Rio Grande do Sul 91540000, Brazil.
authors.forename: José A
authors.initials: JA
authors.lastname: Martinelli
authors.affiliation: Department of Genetics and Pre-Breeding, National Institute of Agricultural Botany, Huntington Road, Cambridge, Cambridgeshire CB3 0LE, UK.
authors.forename: Francesca
authors.initials: F
authors.lastname: Stefanato
authors.affiliation: Department of Genetics and Pre-Breeding, National Institute of Agricultural Botany, Huntington Road, Cambridge, Cambridgeshire CB3 0LE, UK ; Department of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire AL10 9AB, UK.
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Boyd
keywords: APR, adult plant resistance; AQP1, aquaporin; COMT1, caffeic acid O-methyltransferase; ETI, Effector-Triggered-Immunity; FREX, fructan exohydrolase; G6DPH, glucose-6-phosphate dehydrogenase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HSP80, heat shock protein 80; LHC, light-harvesting complex; LTP, type 1 non-specific lipid transfer protein precursor; MIP, major intrinsic proteins; NADPH, nicotinamide adenine dinucleotide phosphate; PAL, phenylalanine ammonia-lyase; PR, pathogenesis-related; PRA2, class III peroxidase; PTI, PAMP-Triggered-Immunity; Pre-haustorial; Puccinia triticina; Quantitative PCR; RBR1, retinoblastoma related protein 1; ROS, reactive oxygen species; Triticum aestivum (L.) thell; WCAB, chlorophyll a/b-binding protein WCAB precursor; Wheat breeding; ZIP5, putative zinc transporter; hai, hours after inoculation; qPCR, quantitative PCR