RESUMO
Fruit size is a highly important trait for most fruit and vegetable crops. This trait has been a main selection target and could be involved in divergent selection processes leading to the differentiation between modern table and wine cultivars. Even though its determination is highly influenced by cultural practices, several regions within the grapevine genome have been identified affecting berry size, either directly or indirectly through their effect on seed content. Using grapevine seeded cultivars, we have analyzed the relationship between ovary cell number and the final size of ovaries and berry fruits. We also performed the characterization of the grapevine AINTEGUMENTA-LIKE family, since it is well reported in Arabidopsis that AINTEGUMENTA (ANT) regulates cell proliferation and organ growth in flower organ primordia by maintaining the meristematic competence of cells during organogenesis. Here we show that orthologous grapevine gene expression associate with flower developmental stages suggesting a similar biological role for this gene family in this species. Moreover, we detected a correlation between those organs size and the level of expression of VviANT1 the grapevine homolog of AtANT. This grapevine gene also co-localizes in linkage group 18 with the confidence interval of a previously detected QTL for berry size. Thus our results suggest the involvement of ANT in the regulation of berry size in grapevine.
Assuntos
Flores/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo , Vitis/metabolismo , Sequência de Bases , Mapeamento Cromossômico , Cromossomos de Plantas , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Proteínas de Ligação a RNA/genética , Especificidade da Espécie , Fatores de Transcrição/genética , Vitis/genética , Vitis/crescimento & desenvolvimentoRESUMO
Anthocyanin profiles are commonly used for grapevine cultivar identification because it is currently accepted that this trait is closely related to their genetic characteristics. Nevertheless, the extent of the variation for the anthocyanin profiles among clones of the same cultivar has not yet been studied in depth. The relative concentration of anthocyanins of 131 Malbec clones grown in the same vineyard was investigated by HPLC-DAD and the use of comprehensive statistic procedures. Complementarily, the expression level of structural and regulatory genes was studied via real time polymerase chain reaction. Significant variation was identified among the profiles of the clones, mainly due to variations in the amounts of malvidin derivatives. Finally, the differential expression in F3'5'H, OMT1 and AM2 genes seems to be related to the malvidin content variation. This work shows the existence of variation for the anthocyanin profiles among clones from the same grapevine cultivar and the putative involvement of genes related to hydroxylation, methylation, and transport of anthocyanins on the basis of such variation.
Assuntos
Antocianinas/análise , Expressão Gênica , Vitis/química , Vitis/genética , Células Clonais , Frutas/química , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Extratos Vegetais/química , Especificidade da Espécie , Vitis/classificaçãoRESUMO
BACKGROUND: Ultraviolet-B radiation (UV-B, 280-315 nm) is a natural component of sunlight, which has numerous regulatory effects on plant physiology. The nature of the response to UV-B is dependent on fluence rate, dose, duration and wavelength of the UV-B treatment. Some reports have analyzed the changes in gene expression caused by UV-B light on several plant species using microarray technology. However, there is no information on the transcriptome response triggered by UV-B in grapevine. In this paper we investigate the gene expression responses of leaves from in vitro cultured Vitis vinifera cv. Malbec plants subjected to the same dose of biologically effective UV-B radiation (4.75 kJ m-2 d-1) administered at two different fluence rates (16 h at â 8.25 µW cm-2, 4 h at â 33 µW cm-2) using a new custom made GrapeGen Affymetrix GeneChip®. RESULTS: The number of genes modulated by high fluence rate UV-B doubled the number of genes modulated by low fluence UV-B. Their functional analyses revealed several functional categories commonly regulated by both UV-B treatments as well as categories more specifically modulated depending on UV-B fluence rate. General protective responses, namely the induction of pathways regulating synthesis of UV-B absorbing compounds such as the Phenylpropanoid pathway, the induction of different antioxidant defense systems and the activation of pathways commonly associated with pathogen defense and abiotic stress responses seem to play critical roles in grapevine responses against UV-B radiation. Furthermore, high fluence rate UV-B seemed to specifically modulate additional pathways and processes in order to protect grapevine plantlets against UV-B-induced oxidative stress, stop the cell cycle progression, and control protein degradation. On the other hand, low fluence rate UV-B regulated the expression of specific responses in the metabolism of auxin and abscisic acid as well as in the modification of cell walls that could be involved in UV-B acclimation-like processes. CONCLUSION: Our results show the UV-B radiation effects on the leaf transcriptome of grapevine (Vitis vinifera cv. Malbec) plantlets. Functional categories commonly modulated under both UV-B treatments as well as transcripts specifically regulated in an UV-B-intensity dependent way were identified. While high fluence rate UV-B had regulatory effects mainly on defense or general multiple-stress responses pathways, low fluence rate UV-B promoted the expression of genes that could be involved in UV-B protection or the amelioration of the UV-B-induced damage. This study also provides an extensive list of genes regulating multiple metabolic pathways involved in the response of grapevine to UV-B that can be used for future researches.