Reference genes for transcriptional analysis of flowering and fruit ripening stages in apple (Malus 3 domestica Borkh.).

Apple (Malus 9 domestica Borkh.) is the most important deciduous tree fruit crop grown around the world. Comparisons of gene expression profiles from different tissues, conditions or cultivars are valuable scientific tools to better understand the gene expression changes behind important silvicultural and nutritional traits. However, the accuracy of techniques employed to access gene expression is dependent on the evaluation of stable reference genes for data normalization to avoid statistical significance undue or incorrect conclusions. The objective of this work was to select the best genes to be used as references for gene expression studies in apple trees by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Vegetative and reproductive tissues of the apple ??Gala?? cultivar were evaluated during their seasonal cycle of growth and dormancy. The expression of 23 traditional housekeeping genes or genes suggested as constitutive by microarray data was investigated. Tested combinations of primers allowed the specific amplification and the generation of suitable efficiency curves for gene expression studies by RT-qPCR. Gene stability was determined by two different statistical descriptors, geNorm and Norm-Finder. The known variable PAL gene expression was used to validate selected normalizers. Results obtained allowed us to conclude that MDH, SAND, THFS, TMp1 and WD40 are the best reference genes to accurately normalize the relative transcript abundances using RT-qPCR in various tissues of apple.DOI 10.1007/s11032-014-0078-

Avaliação da expressão e identificação de genes diferencialmente regulados durante o desenvolvimento do fruto das cultivares de uva Isabel e Isabel Precoce.

A maturação precoce é uma caracteristica agronômica desejada nos programas de melhoramento genético de uvas, pois permite a ampliação do periodo de processamento na vitivinicultura tradicional, e também a obtenção de duas safras por ano em regiões tropicais. Portanto, a compreensão da regulação da expressão gênica associada à maturação do fruto toma-se um pré-requisito essencial ao desenvolvimento de ferramentas aplicadas ao melhoramento genético que possibilitem, por exemplo, a seleção assistida e modificação do amadurecimento.Resumo

Seleção de genes-referência para estudos de expressão gênica utilizando PCR quantitativa em macieiras.

A macieira (Malus x domestica) é uma das mais importantes frutíferas do mundo, e sua produção tem destaque na região sul do Brasil.Resumo publicado também no ENCONTRO DE INICIAÇÃO CIENTÍFICA, 8.; ENCONTRO DE PÓS-GRADUANDOS DA EMBRAPA UVA E VINHO, 4., 2010, Bento Gonçalves. Resumos. Bento Gonçalves: Embrapa Uva e Vinho, 2010; e REUNIÃO ANUAL DO PROGRAMA DE PÓS-GRADUAÇÃO EM BIOLOGIA CELULAR E MOLECULAR DO CENTRO DE BIOTECNOLOGIA DA UFRGS, 12., 2010, Porto Alegre. Livro de resumos. Porto Alegre: UFRGS, 2010

Proteínas de choque térmico e tolerância a altas temperaturas em plantas.

Estresse térmico e as proteínas HSPS. Altas temperaturas e regulação da expressão dos genes das HSPS em plantas. Classificação e ocorrência das HSPS. Carcterização das HSPS. Função dos principais grupos de HSPS. Aquisição de termo-tolerância pelas plantas. Algumas considerações relacionadas aos métodos para avaliação da síntese de HSPS.bitstream/CNPAB-2010/27277/1/doc080.pd

Perfil transcricional comparativo de genes associados ao desenvolvimento do fruto das cultivares de uva Isabel e Isabel Precoce (Vitis labrusca L.).

A cultivar de uva Isabel Precoce é resultante de uma mutação somática espontânea da cultivar Isabel (Vitis labrusca) caracterizada pela antecipação da colheita em cerca de trinta dias. As cultivares precoces permitem aos produtores, a possibilidade de programar o período de colheita para janelas de mercado com preços mais atrativos, podendo com isso, agregar valor ao produto.Resumo

Differential transcriptional profiles of dormancy-related genes in apple buds

The production of temperate fruit crops depends on plant developmental processes, primarily the shift from the juvenile phase to the reproductive phase, dormancy transitions and flowering. Apple tree (Malus ×domestica Borkh.) development is regulated by chilling temperatures, which are required for bud dormancy progression. The apple cultivar Castel Gala is a spontaneous mutation of "Gala Standard". "Castel Gala" is characterized by a 50 % decrease in the chilling requirement (CR) for dormancy release, which results in an earlier budbreak. This work explores the contrasting phenotypes of these cultivars using suppression subtractive hybridization (SSH). From 1,019 unigenes identified by SSH, we selected 28 candidate genes putatively associated with dormancy cycling. Reverse transcription-quantitative polymerase chain reaction was used to validate the differential expression profiles and to transcriptionally characterize these genes in three distinct apple cultivars ("Castel Gala", "Royal Gala" and "Fuji Standard") during a cycle comprising growth to dormancy. Of the 28 candidate genes analyzed, 17 confirmed the differences in expression predicted by SSH. Seasonal transcript accumulation during the winter was observed for several genes, with higher steady-state mRNA levels maintained longer in cultivars with a high CR. The transcription profiles suggest that these genes may be associated with dormancy establishment and maintenance. Of the 17 candidate genes, transcripts coding for dormancy-associated MADS-box (DAM), dehydrins, GAST1, LTI65, NAC, HTA8, HTA12 and RAP2.12-like proteins displayed major differences in gene expression between cultivars through the winter. These genes were therefore considered good candidates for key roles in the dormancy process in apple trees.DOI 10.1007/s11105-013-0690-

Dormancy-related transcript accumulation of the dehydrin gene family in apple buds.

Resumo

The MADS-box gene Agamous-like 11 is essential for seed morphogenesis in grapevine.

Despite the wide appreciation of seedless grapes, little is known about the molecular mechanisms that drive the stenospermocarpic seedless-type phenotype in grapevine. In order to address the molecular mechanisms that control seedlessness in grapevine, our study aimed to characterize VviAGL11, a class D MADS-box transcription factor gene that has been proposed as the major candidate gene involved in Vitis vinifera seed morphogenesis. VviAGL11 allelic variations in seeded and seedless grapevine cultivars were determined, and its correlations with allele-specific steady-state mRNA levels were investigated. VviAGL11 relative expression was significantly higher in seeds at 2, 4, and 6 weeks after fruit set, whereas in the seedless grape its transcript levels were extremely low in all stages analyzed. In situ hybridization revealed transcript accumulation specifically in the dual endotesta layer of the seeds, which is responsible for elongation and an increase of cell number, a necessary step to determine the lignification and the final seed size. No hybridization signals were visible in the seedless grapevine tissues, and a morphoanatomical analysis showed an apparent loss of identity of the endotesta layer of the seed traces. Ectopic expression of VviAGL11 in the Arabidopsis SEEDSTICK mutant background restored the wild-type phenotype and confirmed the direct role of VviAGL11 in seed morphogenesis, suggesting that depletion of its expression is responsible for the erroneous development of a highly essential seed layer, therefore culminating in the typical apirenic phenotype. Key words: Apireny, grapevine, in situ hybridization, seedlessness, Sultanine, VviAGL11