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Chiara Tonelli

Bio: Chiara Tonelli is an academic researcher from University of Milan. The author has contributed to research in topics: Arabidopsis & Gene. The author has an hindex of 45, co-authored 113 publications receiving 7481 citations.


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Journal ArticleDOI
TL;DR: An Arabidopsis thaliana line that is mutant for the R2R3 MYB gene, AtMYB4, shows enhanced levels of sinapate esters in its leaves, indicating that derepression is an important mechanism for acclimation to UV‐B in A.thaliana.
Abstract: An Arabidopsis thaliana line that is mutant for the R2R3 MYB gene, AtMYB4, shows enhanced levels of sinapate esters in its leaves. The mutant line is more tolerant of UV-B irradiation than wild type. The increase in sinapate ester accumulation in the mutant is associated with an enhanced expression of the gene encoding cinnamate 4-hydroxylase, which appears to be the principal target of AtMYB4 and an effective rate limiting step in the synthesis of sinapate ester sunscreens. AtMYB4 expression is downregulated by exposure to UV-B light, indicating that derepression is an important mechanism for acclimation to UV-B in A.thaliana. The response of target genes to AtMYB4 repression is dose dependent, a feature that operates under physiological conditions to reinforce the silencing effect of AtMYB4 at high activity. AtMYB4 works as a repressor of target gene expression and includes a repression domain. It belongs to a novel group of plant R2R3 MYB proteins involved in transcriptional silencing. The balance between MYB activators and repressors on common target promoters may provide extra flexibility in transcriptional control.

794 citations

Journal ArticleDOI
TL;DR: Understanding of the regulation of anthocyanin synthesis in flowers and fruits is broadened, indicating that a regulatory system based on the cooperation of MYB, bHLH and WD40 proteins that control floral and fruit pigmentation is common to many dicot species.

650 citations

Journal ArticleDOI
TL;DR: A systematic search for the function of all genes of this large family of regulatory genes in Arabidopsis thaliana revealed conserved amino acid motifs shared by subgroups of R2R3-MYB genes in addition to the characteristic DNA-binding domain.
Abstract: Transcription factors containing a conserved DNA-binding domain similar to that of the proto-oncogene c-myb have been identified in nearly all eukaryotes. MYB-related proteins from plants generally contain two related helix-turn-helix motifs, the R2 and R3 repeats. It was estimated that Arabidopsis thaliana contains more than 100 R2R3-MYB genes. The few cases where functional data are available suggest an important role of these genes in the regulation of secondary metabolism, the control of cell shape, disease resistance, and hormone responses. To determine the full regulatory potential of this large family of regulatory genes, a systematic search for the function of all genes of this family was initiated. Sequence data for more than 90 different A. thaliana R2R3-MYB genes have been obtained. Sequence comparison revealed conserved amino acid motifs shared by subgroups of R2R3-MYB genes in addition to the characteristic DNA-binding domain. No significant clustering of the genes was detected, although they are not uniformly distributed throughout the A. thaliana genome.

570 citations

Journal ArticleDOI
TL;DR: The analysis of the genomic organization and expression of these genes in response to light shows that PAL and StSy genes belong to large multigene families, while the others are present in one to four copies per haploid genome.
Abstract: Genes involved in flavonoid and stilbene biosynthesis were isolated from grape (Vitis vinifera L.). Clones coding for phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX) and UDP glucose:flavonoid 3-O-glucosyl transferase (UFGT), were isolated by screening a cDNA library, obtained from mRNA from seedlings grown in light for 48 h using snapdragon (Antirrhinum majus) and maize heterologous probes. A cDNA clone coding for stilbene synthase (StSy) was isolated by probing the library with a specific oligonucleotide. These clones were sequenced and when the putative products were compared to the published amino acid sequence for corresponding enzymes, the percentages of similarity ranged from 65% (UFGT) to 90% (CHS and PAL). The analysis of the genomic organization and expression of these genes in response to light shows that PAL and StSy genes belong to large multigene families, while the others are present in one to four copies per haploid genome. The steady-state level of mRNAs encoded by the flavonoid biosynthetic genes as determined in young seedlings is coordinately induced by light, except for PAL and StSy, which appear to be constitutively expressed.

475 citations

Journal ArticleDOI
TL;DR: The characterization of AtMYB60, a R2R3-MYB gene of Arabidopsis, is reported as the first transcription factor involved in the regulation of stomatal movements and opens new possibilities to engineeringStomatal activity to help plants survive desiccation.

470 citations


Cited by
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Journal ArticleDOI
TL;DR: The elucidation ofMYB protein function and regulation that is possible in Arabidopsis will provide the foundation for predicting the contributions of MYB proteins to the biology of plants in general.

3,542 citations

01 Apr 2012
TL;DR: International experts in cancer prevention analyse global research on diet nutrition physical activity cancer and make public health policy recommendations, the fractions of cancer attributable to potentially modifiable factors are analyzed.
Abstract: physical activity and cancer fact sheet national cancer on this page what is physical activity what is known about the relationship between physical activity and cancer risk how might physical activity be, diet and cancer report american institute for cancer the american institute for cancer research aicr is the cancer charity that fosters research on diet and cancer prevention and educates the public about the results, download resources and toolkits world cancer research downloads for scientists from the wcrf aicr third expert report diet nutrition physical activity and cancer a global perspective, nutritional science university of washington school of public health school of public health nutritional science detailed course offerings time schedule are available for spring quarter 2019, 2019 aicr research conference american institute for about aicr we fund cutting edge research and give people practical tools and information to help them prevent and survive cancer more about aicr, agence fruits et l gumes frais aprifel the global fruit and veg newsletter is a monthly newsletter distributing to 29 countries involved in the promotion of the consumption of fruit and vegetable worldwide, world cancer research fund international we are experts in cancer prevention we analyse global research on diet nutrition physical activity cancer and make public health policy recommendations, the fractions of cancer attributable sciencedirect com a proportion of cancers at many body sites are attributable to potentially modifiable factors no global summaries of the preventable cancer burden have been, who controlling the global obesity epidemic more information obesity and overweight fact sheet who global strategy on diet physical activity and health who global database on body mass index, espen guidelines on nutrition in cancer patients gl nutrition in cancer patients outline o methods o1 basic information o2 methods o3 post publication impact a background a1 catabolic alterations in, un news global perspective human stories un news produces daily news content in arabic chinese english french kiswahili portuguese russian and spanish and weekly programmes in hindi urdu and bangla, recommended community strategies and measurements to table continued summary of recommended community strategies and measurements to prevent obesity in the united states strategies to encourage physical, food as medicine preventing treating the most dreaded food as medicine preventing treating the most dreaded diseases with diet, video resources bc cancer these videos help patients learn about their cancer and its treatment, prostate cancer nutrition and dietary supplements pdq nutrition methods and dietary supplements have been studied for prostate cancer prevention or treatment read about the history of research laboratory, who europe food safety food safety ingestion and handling of contaminated food causes significant illness and death worldwide across the who european region foodborne diseases, creating healthy food and eating environments policy and food and eating environments likely contribute to the increasing epidemic of obesity and chronic diseases over and above individual factors such as knowledge skills, health risks obesity prevention source harvard t h obesity and reproduction obesity can influence various aspects of reproduction from sexual activity to conception among women the association between, top nutrition schools undergraduate degree programs ncr want to know the top nutrition schools and best undergraduate degree programs here we review analyze rank rate them figure out which is best for you , overeating caloric restriction and breast cancer risk by this study analyzes the association of excessive energy intake and caloric restriction with breast cancer bc risk taking into account the individual, calcium what s best for your bones and health the possible increased risk of ovarian cancer high levels of galactose a sugar released by the digestion of lactose in milk have been studied as being, cancer protocol nutrition supplements cancer protocol nutrition supplements herbs enzymes note do not email me unless you would like a personalized protocol free with a suggested donation of 250

2,202 citations

Journal ArticleDOI
TL;DR: Lignin is the generic term for a large group of aromatic polymers resulting from the oxidative combinatorial coupling of 4-hydroxyphenylpropanoids, deposited predominantly in the walls of secondarily thickened cells, making them lignin-like polymers.
Abstract: Lignin is the generic term for a large group of aromatic polymers resulting from the oxidative combinatorial coupling of 4-hydroxyphenylpropanoids ([Boerjan et al., 2003][1]; [Ralph et al., 2004][2]). These polymers are deposited predominantly in the walls of secondarily thickened cells, making them

1,956 citations

Journal ArticleDOI
TL;DR: Improved understanding of the molecular and biochemical mechanisms by which plants respond to elevated [CO2], and the feedback of environmental factors upon them, will improve the ability to predict ecosystem responses to rising [ CO2] and increase the potential to adapt crops and managed ecosystems to future atmospheric [CO 2].
Abstract: This review summarizes current understanding of the mechanisms that underlie the response of photosynthesis and stomatal conductance to elevated carbon dioxide concentration ([CO2]), and examines how downstream processes and environmental constraints modulate these two fundamental responses. The results from free-air CO2 enrichment (FACE) experiments were summarized via meta-analysis to quantify the mean responses of stomatal and photosynthetic parameters to elevated [CO2]. Elevation of [CO2] in FACE experiments reduced stomatal conductance by 22%, yet, this reduction was not associated with a similar change in stomatal density. Elevated [CO2] stimulated light-saturated photosynthesis (Asat) in C3 plants grown in FACE by an average of 31%. However, the magnitude of the increase in Asat varied with functional group and environment. Functional groups with ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-limited photosynthesis at elevated [CO2] had greater potential for increases in Asat than those where photosynthesis became ribulose-1,5-bisphosphate (RubP)-limited at elevated [CO2]. Both nitrogen supply and sink capacity modulated the response of photosynthesis to elevated [CO2] through their impact on the acclimation of carboxylation capacity. Increased understanding of the molecular and biochemical mechanisms by which plants respond to elevated [CO2], and the feedback of environmental factors upon them, will improve our ability to predict ecosystem responses to rising [CO2] and increase our potential to adapt crops and managed ecosystems to future atmospheric [CO2].

1,836 citations

Journal ArticleDOI
TL;DR: Systematic screens for knockout mutations in MYB genes, followed by phenotypic analyses and the dissection of mutants with interesting phenotypes, have started to unravel the functions of the 125 R2R3-MYB genes in Arabidopsis thaliana.

1,779 citations