Uso de microarrays para a análise do perfil transcricional em polpa de maçã cv. Gala frente ao armazenamento refrigerado e ao uso do 1-metilciclopropeno.

O presente trabalho utilizou a técnica de microarrays para o estudo da influência do 1-metilciclopropeno (1-MCP) e do AR sobre o perfil transcricional de polpa de maçã 'Gala' armazenada por 60 dias

Effects of pre-harvest gibberellic acid spraying on gene transcript accumulation during peach fruit development.

In order to understand early molecular events associated with increase in fruit size and woolliness prevention induced by pre-harvest gibberellic acid (GA3) spraying, differential transcript accumulation of genes encoding proteins putatively involved in protein folding and protection, cell wall metabolism, and endomembrane transport was studied during fruit development of ?Chiripa´? peach. Woolliness occurrence reached 100% in untreated peach, was reduced by 15% with GA3 spraying at the end of the pit hardening stage and was significantly reduced (by 78%) in peaches treated at the beginning of the pit hardening stage despite a significantly increased fruit size. Low incidence of woolliness after cold storage and fruit size increase in early GA3 treated peach was correlated with high transcript accumulation of genes encoding proteins putatively involved in protein folding, and protection of the endoplasmic reticulum (heat shock proteins?HSP40 er) and chloroplast (HSP17.8 ch), endomembrane transport (GTPase), as well as genes involved in cell wall loosening (expansins?Exp1, Exp2, Exp3, Exp4)

Identification of biomarkers associated to 'Gala' apples ripening and postharvest quality .

Apple is, sociocultural and economically, on of the most important species in the world, and stands out for its high storage potential. However, the monitoring of factors that could result in fruit quality modifications during postharvest is essential to ensure the acceptability and for the development of new storage technologies in order to increase fruit shelf life. Approaches focused on molecular biology, such as RT-qPCR have been used to better understand the mechanisms involved in fruit development and maturation. In this study the use of RT-qPCR to monitoring apple quality during ripening and development in different postharvest conditions such as room temperature, cold storage with or without control of atmosphere and the 1-methylcyclopropene usage were proposed. The potential of genes involved in ethylene biosynthesis and response, cell wall modification and degradation, sugar and aroma metabolisms for employment as biomarkers of fruit development and quality were evaluated. Thus MdEXP4 is highlighted as biomarker for development and MdACO1, MdPG1, MdAF1, MdAF3 and MdAAT2 as potential biomarkers for ripening. MdACO1 and MdPG1 appear as suitable markers for quality, conservation technologies and storage time in apples. This work suggests that the study of gene expression by RT-qPCR may be an alternative for a better fruit characterization during the development and postharvest period. Keywords: Cold storage, gene expression, Malus x domestica, molecular analysi

Selection of reliable reference genes for quantitative real-time polymerase chain reaction studies in maize grains.

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Genome-wide analysis of the AP2/ERF superfamily in apple and transcriptional evidence of ERF involvement in scab pathogenesis.

The APETALA2 (AP2)/ETHYLENE RESPONSE FACTOR (ERF) superfamily of transcriptional regulators is involved in several growth, development and stress responses processes in higher plants. Currently, the available information on the biological roles of AP2/ERF genes is derived from Arabidopsis thaliana. In the present work, we have investigated genomic and transcriptional aspects of AP2/ERF genes in the economically important perennial species, Malus × domestica. We have identified 259 sequences containing at least one ERF domain in apple genome. The vast majority of the putative proteins display predicted nuclear localization, compatible with a biological role in transcription regulation. The AP2 and ERF families are greatly expanded in apple. Wholegenome analyses in other plant species have identified a single genomic sequence with divergent ERF, whereas in apple seven soloists are present. In the apple genome, the most noteworthy expansion occurred in subgroups V, VIII and IX of the ERF family. Expression profiling analyses have revealed the association of ripeninginvolved ERF genes to scab (Venturia inequalis) pathogenesis in the susceptible Gala cultivar, indicating that gene expansion processes were accompanied by functional divergence. The presented analyses of AP2/ERF genes in apple provide evidences of shared ethylenemediated signaling pathways in ripening and disease responses