Francesca Quattrocchio - Academia.edu (original) (raw)

Papers by Francesca Quattrocchio

The Petunia hybrida genes ANTHOCYANIN1 (AN1) and AN2 encode transcription factors with a basic-he... more The Petunia hybrida genes ANTHOCYANIN1 (AN1) and AN2 encode transcription factors with a basic-helix-loop-helix (BHLH) and a MYB domain, respectively, that are required for anthocyanin synthesis and acidification of the vacuole in petal cells. Mutation of PH4 results in a bluer flower color, increased pH of petal extracts, and, in certain genetic backgrounds, the disappearance of anthocyanins and fading of the flower color. PH4 encodes a MYB domain protein that is expressed in the petal epidermis and that can interact, like AN2, with AN1 and the related BHLH protein JAF13 in yeast two-hybrid assays. Mutation of PH4 has little or no effect on the expression of structural anthocyanin genes but strongly downregulates the expression of CAC16.5, encoding a protease-like protein of unknown biological function. Constitutive expression of PH4 and AN1 in transgenic plants is sufficient to activate CAC16.5 ectopically. Together with the previous finding that AN1 domains required for anthocyanin synthesis and vacuolar acidification can be partially separated, this suggests that AN1 activates different pathways through interactions with distinct MYB proteins. falw.vu.nl; fax 31-20-5987155.

PloS one, 2015

Anthocyanins are water-soluble polyphenolic compounds with a high nutraceutical value. Despite th... more Anthocyanins are water-soluble polyphenolic compounds with a high nutraceutical value. Despite the fact that cultivated tomato varieties do not accumulate anthocyanins in the fruit, the biosynthetic pathway can be activated in the vegetative organs by several environmental stimuli. Little is known about the molecular mechanisms regulating anthocyanin synthesis in tomato. Here, we carried out a molecular and functional characterization of two genes, SlAN2 and SlANT1, encoding two R2R3-MYB transcription factors. We show that both can induce ectopic anthocyanin synthesis in transgenic tomato lines, including the fruit. However, only SlAN2 acts as a positive regulator of anthocyanin synthesis in vegetative tissues under high light or low temperature conditions.

Nature Biotechnology, 1999

The Science of Flavonoids, 2006

Petunia, 2009

With nearly a century of excellent research on the biochemistry and inheritance of color, and the... more With nearly a century of excellent research on the biochemistry and inheritance of color, and the corresponding development of incredible genetic resources, Petunia has offered perhaps the best genetic system for molecular analysis of flower color. The knowledge and materials available to the Petunia geneticist, together with the tools of genetic engineering, have allowed for the isolation and characterization of a large number of genes affecting flower color, including those encoding biosynthetic enzymes, regulators of their expression, and vacuolar function. Here we summarize current knowledge about the genes responsible for the amazing diversity of colors and color patterns observable in the genus Petunia and propose some evolutionary implications of these findings.

Trends in Plant Science, 2005

The Plant Journal, 2011

Petunia is an excellent model system, especially for genetic, physiological and molecular studies... more Petunia is an excellent model system, especially for genetic, physiological and molecular studies. Thus far, however, genome-wide expression analysis has been applied rarely because of the lack of sequence information. We applied next-generation sequencing to generate, through de novo read assembly, a large catalogue of transcripts for Petunia axillaris and Petunia inflata. On the basis of both transcriptomes, comprehensive microarray chips for gene expression analysis were established and used for the analysis of global-and organ-specific gene expression in Petunia axillaris and Petunia inflata and to explore the molecular basis of the seed coat defects in a Petunia hybrida mutant, anthocyanin 11 (an11), lacking a WD40-repeat (WDR) transcription regulator. Among the transcripts differentially expressed in an11 seeds compared with wild type, many expected targets of AN11 were found but also several interesting new candidates that might play a role in morphogenesis of the seed coat. Our results validate the combination of next-generation sequencing with microarray analyses strategies to identify the transcriptome of two petunia species without previous knowledge of their genome, and to develop comprehensive chips as useful tools for the analysis of gene expression in P. axillaris, P. inflata and P. hybrida.

The Plant Journal, 1995

The Petunia hybrida line W138 contains more than 200 copies of the transposable element dTphl. In... more The Petunia hybrida line W138 contains more than 200 copies of the transposable element dTphl. In W138 progeny these elements give rise to new unstable mutations at high frequency. With the aim of isolating these mutated genes a method was developed to isolate dTphl flanking sequences unique for mutant plants. This method is based on differential screening of cloned inverse polymerese chain reaction (IPCR) products originating from the mutated plant. It directly yields e probe for the mutated gene which can be used to screen pre-existing cDNA and genomic libraries. This method may be generally applicable to isolate genes tagged by other high copy number transposable elements, like Mutator (Mu) or Dissociation (Ds) in Zea mays.

The Plant Journal, 1998

The regulatory anthocyanin loci, an1, an2, an4 and an11 of Petunia hybrida, and r and c1 from Zea... more The regulatory anthocyanin loci, an1, an2, an4 and an11 of Petunia hybrida, and r and c1 from Zea mays, control transcription of different sets of target genes. Both an2 and c1 encode a MYB-type protein. This study reports the isolation of a P. hybrida gene, jaf13, encoding a basic helix-loop-helix protein that, on the basis of sequence homology and intron/exon structure, represents the P. hybrida orthologue of the Z. mays r genes. Ectopic expression of an2 and jaf13 is sufficient for activation of the dihydroflavonol 4-reductase-A (dfrA) promoter and enhanced pigment accumulation in P. hybrida. This indicates that an2 and jaf13 play a key role in determining the tissue-specific expression pattern of structural genes. However, because chalcone synthase (chs) and flavanone-3-hydroxylase (f3h) are not activated, the pattern of pigmentation is not fundamentally altered. Expression of an2 in Z. mays complements a mutation in pl, a c1 paralogue, indicating that an2 activates a wider set of target genes in this host. Transient expression assays in Z. mays and P. hybrida tissues showed that C1 and R or AN2 and JAF13 can activate the promoter of the c2 gene, encoding Z. mays CHS, but not the chsA promoter from P. hybrida. These results indicate that regulatory anthocyanin genes are conserved between species and that divergent evolution of the target gene promoters is responsible for the species-specific differences in regulatory networks.

THE PLANT CELL ONLINE, 1990

Chalcone synthase (CHS) catalyzes the first step in the biosynthesis of flavonoids that function ... more Chalcone synthase (CHS) catalyzes the first step in the biosynthesis of flavonoids that function in flower pigmentation, protection against stress, and induction of nodulation. The petunia genome contains eight complete chs genes, of which four are differentially expressed in floral tissues and UV-light-induced seedlings. The 5'-flanking regions of these four chs genes were fused to the 8-glucuronidase (GUS) reporter gene and introduced into petunia plants by Agrobacterium-mediated transformation. We show that expression of each construct is identical to the expression of the authentic chs gene, implying that the differences in expression pattern between these chs genes are caused at least in part by their promoters. Histochemical analyses of GUS expression show that chs promoters are not only active in pigmented cell types (epidermal cells of the flower corolla and tube and [sub] epidermal cells of the flower stem) but also in a number of unpigmented cell types (mesophylic cells of the corolla, several cell types in the ovary and the seed coat). Comparison of chs-GUS expression and flavonoid accumulation patterns in anthers suggests that intercellular transport of flavonoids and enzymes occurs in this organ. Analysis of the flavonoids accumulated in tissues from mutant lines shows that only a subset of the genes that control flavonoid biosynthesis in the flower operates in the ovary and seed. This implies that (genetic) control of flavonoid biosynthesis is highly tissue specific.

THE PLANT CELL ONLINE, 2002

ANTHOCYANIN1 (AN1) of petunia is a transcription factor of the basic helix-loop-helix (bHLH) fami... more ANTHOCYANIN1 (AN1) of petunia is a transcription factor of the basic helix-loop-helix (bHLH) family that is required for the synthesis of anthocyanin pigments. Here, we show that AN1 controls additional aspects of cell differentiation: the acidification of vacuoles in petal cells, and the size and morphology of cells in the seed coat epidermis. We identified an1 alleles, formerly known as ph6 , that sustain anthocyanin synthesis but not vacuolar acidification and seed coat morphogenesis. These alleles express truncated proteins lacking the C-terminal half of AN1, including the bHLH domain, at an ‫ف‬ 30-fold higher level than wild-type AN1. An allelic series in which one, two, or three amino acids were inserted into the bHLH domain indicated that this domain is required for both anthocyanin synthesis and vacuolar acidification. These findings show that AN1 controls more aspects of epidermal cell differentiation than previously thought through partially separable domains.

The Plant Cell, 2000

... Cornelis Spelt a , Francesca Quattrocchio a , Joseph NM Mol a , and Ronald Koes a a Departmen... more ... Cornelis Spelt a , Francesca Quattrocchio a , Joseph NM Mol a , and Ronald Koes a a Department of Genetics, Institute for Molecular Biological Sciences, Vrije Universiteit, Biocentrum Amsterdam, de Boelelaan 1087, 1081 HV Amsterdam, The Netherlands ...

THE PLANT CELL ONLINE, 2006

THE PLANT CELL ONLINE, 1999

The shape and color of flowers are important for plant reproduction because they attract pollinat... more The shape and color of flowers are important for plant reproduction because they attract pollinators such as insects and birds. Therefore, it is thought that alterations in these traits may result in the attraction of different pollinators, genetic isolation, and ultimately, (sympatric) speciation. Petunia integrifolia and P. axillaris bear flowers with different shapes and colors that appear to be visited by different insects. The anthocyanin2 ( an2 ) locus, a regulator of the anthocyanin biosynthetic pathway, is the main determinant of color differences. Here, we report an analysis of molecular events at the an2 locus that occur during Petunia spp evolution. We isolated an2 by transposon tagging and found that it encodes a MYB domain protein, indicating that it is a transcription factor. Analysis of P. axillaris subspecies with white flowers showed that they contain an2 Ϫ alleles with two alternative frameshifts at one site, apparently caused by the insertion and subsequent excision of a transposon. A third an2 ؊ allele has a nonsense mutation elsewhere, indicating that it arose independently. The distribution of polymorphisms in an2 ؊ alleles suggests that the loss of an2 function and the consequent changes in floral color were not the primary cause for genetic separation of P. integrifolia and P. axillaris. Rather, they were events that occurred late in the speciation process, possibly to reinforce genetic isolation and complete speciation. Beld, M., Martin, C., Huits, H., Stuitje, A.R., and Gerats, A.G.M. (1989). Flavonoid synthesis in Petunia hybrida: Partial characterization of dihydroflavonol 4-reductase genes. Plant Mol. Biol. 13, 491-502.

THE PLANT CELL ONLINE, 1993

In this study, we demonstrate that in petunia at least four regulatory genes (anthocyanin-7 [anl]... more In this study, we demonstrate that in petunia at least four regulatory genes (anthocyanin-7 [anl], an2, an4, and an77) control transcription of a subset of structural genes from the anthocyanin pathway by using a combination of RNA gel blot analysis, transcription run-on assays, and transient expression assays. an2and an77-mutants could be transiently complemented by the maize regulatory genes Leaf color (Lc) or Colorless-7 (CT), respectively, whereas anímutants only by Lc and C7 together. In addition, the combination of Lc and C7 induces pigment accumulation in young leaves. This indicates that Lc and C7 are both necessary and sufficient to produce pigmentation in leaf cells. Regulatory pigmentation genes in maize and petunia control different sets of structural genes. The maize Lc and C7 genes expressed in petunia differentially activate the promoters of the chalcone synthase genes chsA and chsJ in the same way that the homologous petunia genes do. This suggests that the regulatory proteins in both species are functionally similar and that the choice of target genes is determined by their promoter sequences. We present an evolutionary model that explains the differences in regulation of pigmentation pathways of maize, petunia, and snapdragon.

Proceedings of the National Academy of Sciences, 1995

Establishment of loss-of-function phenotypes is often a key step in determining the biological fu... more Establishment of loss-of-function phenotypes is often a key step in determining the biological function of a gene. We describe a procedure to obtain mutant petunia plants in which a specific gene with known sequence is inactivated by the transposable element dTphl. Leaves are collected from batches of 1000 plants with highly active dTphl elements, pooled according to a three-dimensional matrix, and screened by PCR using a transposon-and a gene-specific primer. In this way individual plants with a dTphl insertion can be identified by analysis of about 30 PCRs. We found insertion alleles for various genes at a frequency of about 1 in 1000 plants. The plant population can be preserved by selfing all the plants, so that it can be screened for insertions in many genes over a prolonged period.

PLANT PHYSIOLOGY, 2014

Anthocyanins are a chemically diverse class of secondary metabolites that color most flowers and ... more Anthocyanins are a chemically diverse class of secondary metabolites that color most flowers and fruits. They consist of three aromatic rings that can be substituted with hydroxyl, sugar, acyl, and methyl groups in a variety of patterns depending on the plant species. To understand how such chemical diversity evolved, we isolated and characterized METHYLATION AT THREE2 (MT2) and the two METHYLATION AT FIVE (MF) loci from Petunia spp., which direct anthocyanin methylation in petals. The proteins encoded by MT2 and the duplicated MF1 and MF2 genes and a putative grape (Vitis vinifera) homolog Anthocyanin O-Methyltransferase1 (VvAOMT1) are highly similar to and apparently evolved from caffeoyl-Coenzyme A O-methyltransferases by relatively small alterations in the active site. Transgenic experiments showed that the Petunia spp. and grape enzymes have remarkably different substrate specificities, which explains part of the structural anthocyanin diversity in both species. Most strikingly, VvAOMT1 expression resulted in the accumulation of novel anthocyanins that are normally not found in Petunia spp., revealing how alterations in the last reaction can reshuffle the pathway and affect (normally) preceding decoration steps in an unanticipated way. Our data show how variations in gene expression patterns, loss-of-function mutations, and alterations in substrate specificities all contributed to the anthocyanins' structural diversity.

Plant Molecular Biology, 1990

The activity, tissue specificity and temporal expression of the tandem promoter region preceding ... more The activity, tissue specificity and temporal expression of the tandem promoter region preceding a maize zein gene (zE19, encoding a 19 kDa zein protein) were tested in transgenic Petunia plants. To simplify the analysis, the tandem promoter as well as each of the two separate promoter regions were fused to the fl-glucuronidase (GUS) reporter gene. All of the three constructs directed the synthesis of GUS in the endosperm of transformed seeds indicating that both separate promoters are independently activated and show the same tissue and cell type specificity observed for zein genes in maize. The kinetics of accumulation and the localization of GU S activity are not coordinated with those of Petunia endogenous seed storage proteins during the development of transformed seeds.

Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2008

Transient expression assays are useful for saving time in studies of gene function, particularly ... more Transient expression assays are useful for saving time in studies of gene function, particularly ones expressed in fruit. Transient expression system of a reporter gene in immature fruit of banana was developed. Agrobacterium tumefaciens, whose plasmid contains an intron-containing β-glucuronidase (gusA) gene under regulatory control of the CaMV 35S promoter, was vacuum-infiltrated into sliced fruits and co-cultured. GUS histochemical assay was performed three days after co-cultivation, and a high level of GUS expression was observed. This transient expression system is useful for routine transient assays to validate genes expressed in banana fruit.

Nature Cell Biology, 2008

The regulation of pH in cellular compartments is crucial for intracellular trafficking of vesicle... more The regulation of pH in cellular compartments is crucial for intracellular trafficking of vesicles and proteins and the transport of small molecules, including hormones. In endomembrane compartments, pH is regulated by vacuolar H + -ATPase 1 (V-ATPase), which, in plants, act together with H + -pyrophosphatases 2 (PPase), whereas distinct P-type H + -ATPases in the cell membrane control the pH in the cytoplasm and energize the plasma membrane 3 . Flower colour mutants have proved useful in identifying genes controlling the pH of vacuoles where anthocyanin pigments accumulate 4,5 . Here we show that PH5 of petunia encodes a P 3A -ATPase proton pump that, unlike other P-type H + -ATPases, resides in the vacuolar membrane. Mutation of PH5 reduces vacuolar acidification in petals, resulting in a blue flower colour and abolishes the accumulation of proanthocyanindins (condensed tannins) in seeds. Expression of PH5 is directly activated by transcription regulators of the anthocyanin pathway, in conjunction with PH3 and PH4. Thus, flower coloration, a key-factor in plant reproduction, involves the coordinated activation of pigment synthesis and a specific pathway for vacuolar acidification.