title: Microarray analysis of differentially expressed mRNAs and miRNAs in young leaves of sorghum under dry-down conditions.
abstract: Sorghum is a C4 plant adapted to semi-arid environments, and characterized by high water-use efficiency. To better understand the molecular and physiological basis of drought response the sorghum genotype IS19453, selected as a drought tolerant line during field trials, was evaluated in a "dry-down" experiment under controlled conditions. The incoming stress was monitored by determining the water potential available for 4-leaf-old plants. Control plants were maintained at approximately 2.5 pF, while water stressed plants were sampled at 3.12, 3.65 and 4.14 pF. Transcriptome analysis was monitored using a high density microarray containing all available sorghum TC sequences. Drought affected gene expression at 4.14 pF; 1205 genes resulted up-regulated. Most of the differentially expressed genes were involved in regulation of transcription (bZIPs, MYBs, HOXs), signal transduction (phosphoesterases, kinases, phosphatases), carbon metabolism (NADP-ME), detoxification (CYPs, GST, AKRs), osmoprotection mechanisms (P5CS) and stability of protein membranes (DHN1, LEA, HSPs). Several of them could be located in stay green QTLs. Eight were selected and validated by qRT-PCR. A dedicated miRNA microarray allowed the identification of four families of miRNAs up-regulated in the earlier phase of stress, while one family was down-regulated. The selected drought related genes could be used to screen for potential drought tolerance in other sorghum genotypes.
authors.affiliation: Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 20122 Piacenza, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Pasini
authors.affiliation: Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 20122 Piacenza, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Bergonti
authors.affiliation: Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 20122 Piacenza, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fracasso
authors.affiliation: Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 20122 Piacenza, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Marocco
authors.affiliation: Istituto di Agronomia, Genetica e Coltivazioni erbacee, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 20122 Piacenza, Italy. Electronic address: stefano.amaducci@unicatt.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Amaducci
mesh_terms: D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020411:Oligonucleotide Array Sequence Analysis; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D040641:Quantitative Trait Loci; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000502:physiology*; D045868:Sorghum / Q000235:genetics / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome
keywords: Differential gene expression; Drought stress; Microarray; Sorghum bicolor