• Istituto di Biologia e Patologia Molecolari

Tel :+390649912337
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Istitute of Molecular Biology and Pathology - National Research Council
Department of Biology and Biotecnology - Charles Darwin
Sapienza University of Rome - Istituto Fisiologia Generale Piano seminterrato stanza 10 - P. le A.Moro 5 00185 Roma

Her career started with a deep interest in the study of the regulation of gene expression, which she addressed in the plant model organism Arabidopsis thaliana. She has developed a strong experience in homeodomain-type of transcription factors, HD-Zips, whose expression is regulated by changes in the quality of the light environment. With her activity, she has given a contribute in the elucidation of a complex network among transcription factors involved in the light-regulated development in Arabidopsis. Recent results have allowed the identification of a signal transduction pathway which begins from light perception by photoreceptors and, via these homeodomain transcription factors, regulate leaf development through the modulation of hormonal levels. In Arabidopsis, there is evidence that cell number contributes to the reduced leaf size of plants grown under simulated shade.  Low R/FR rapidly and transiently reduces the frequency of cell division in young leaf primordia through a non-cell autonomous mechanism that requires the action of the auxin receptor TRANSPORT INHIBITOR RESISTANT 1 (TIR1).  The auxin increase perceived through TIR1 induces CYTOKININ OXIDASE/DEHYDROGENASE 6 (CKX6), a gene encoding an enzyme involved in cytokinin degradation, which in turn promoting cytokinin breakdown diminishes cell proliferation in developing leaf primordia. (Carabelli et al. 2007, 2008).  However, it remains unknown whether the rapid and transient arrest in growth of the leaf primordia is the only effect of shade on Arabidopsis leaf development.  Recent results from our group show that prolonged Low R/FR determines early exit of proliferation in the leaf.  Moreover, through the analysis of single and multiple HD-Zip II - gamma subfamily mutants, we found that this response requires the HD-ZIP II transcription factors ARABIDOPSIS THALIANA HOMEO BOX 2 (ATHB2) and ARABIDOPSIS THALIANA HOMEO BOX 4 (ATHB4). Molecular and genetic analysis will be performed to understand how ATHB2 and ATHB4 control early exit of proliferation under canopy shade.

The function of the light-regulated HD-Zips in plant development is the focus of her most recent research. Particularly, with both genetic and molecular approaches, she has discovered a role for some of the HD-Zip factors in embryo development in normal light condition, and a role in the formation and maintenance of apical and root meristems (Turchi et al., 2013). Moreover, in the double homeobox arabidopsis thaliana 3 (hat3) athb4 mutant background, we observed phenotypes in several flower organs, and we focused on phenotypes of the gynoecium, as the valves appear severely splitted, instead of being tightly fused (Carabelli et al., 2013). This phenotype is resembling the loss of function of the SPATULA (SPT) gene, which is indeed involved in the formation of the style and stigma, the upper part of the gynoecium. In the wild type the apical style region undergoes a transition from a bilaterally symmetric stage to a radially symmetric structure during gynoecium development. Two transcription factors, INDEHISCENT and SPT, are both necessary and sufficient for the radialization process and control style symmetry by directly regulating auxin distribution (Moubayidin et al., 2014). We are evaluating the genetic interactions between HAT3/ATHB4 and SPT by crossing the respective mutant lines and by expression analysis of HAT3 and SPT marker lines in the spt and hat3 athb4 mutants, respectively. Moreover, we are studying auxin dynamics in the hat3 athb4 mutant background in order to evaluate if auxin distribution is also regulated by HAT3 and ATHB4.
1-Ciolfi A, Sessa G, Sassi M, Possenti M, Salvucci S, Carabelli M, Morelli G, Ruberti I. Dynamics of the shade-avoidance response in Arabidopsis. Plant Physiol. 2013. 163(1): 331-53. 

2-Turchi L,  Carabelli M,  Ruzza V, Possenti  M, Sassi M, Peñalosa  A, Sessa G, Salvi S, Forte V, Morelli G, Ruberti I. Arabidopsis HD-Zip II transcription factors control apical embryo development and meristem function. Development. 2013.  140(10):2118-29. 

3-Ruberti I, Sessa G, Ciolfi A, Possenti M, Carabelli M, Morelli G. Plant adaptation to dynamically changing environment: the shade avoidance response. Biotechnol Adv. 2012. 30(5):1047-58.

4-Ciarbelli AR, Ciolfi A, Salvucci S, Ruzza V, Possenti M, Carabelli M, Fruscalzo A, Sessa G, Morelli G, Ruberti I. (2008). The Arabidopsis homeodomain-leucine zipper II gene family: diversity and redundancy. Plant Molecular Biology, vol. 68 (4-5); p. 465-478


5-Carabelli M, Possenti M, Sessa G, Ciolfi A, Sassi M, Morelli G, Ruberti, I. (2008). A novel regulatory circuit underlying plant response to canopy shade. Plant Signalling & Behavior, vol. 3, ISSN: 1559-2324


6-Carabelli M, Possenti M, Sessa G, Ciolfi A, Sassi M, Morelli G, Ruberti I. (2007). Canopy shade causes a rapid and transient arrest in leaf development through auxin-induced cytokinin oxidase activity. Genes & Development, vol. 21; p. 1863-1868


7-Sessa G, Carabelli M, Sassi M, Ciolfi A, Possenti M, Mittempergher F, Becker J, Morelli G, Ruberti I (2005). A dynamic balance between gene activation and repression regulates the shade avoidance response in Arabidopsis. Genes & Development, vol. 19(23); p. 2811-2815


8- Morelli G, Baima S, Carabelli M, Di Cristina M, Lucchetti S, Sessa G, Steindler C, Ruberti I. (1998). Homeodomain-leucine zipper proteins in the control of plant growth and development. In: Last R, Lo Schiavo F, Morelli G, RAIKEL N. EDS. NATO ASI Series, Cellular Integration of Signalling Pathways in Plant Development.


9- Steindler C, Carabelli M, Borello U, Morelli G, Ruberti I. (1997). Phytochrome A, phytochrome B and other phytochrome(s) regulate ATHB-2 gene expression in etiolated and green Arabidopsis plants. Plant, Cell and Environment, vol. 20; p. 759-763


10- Carabelli M, Morelli G, Whitelam G, Ruberti I. (1996). Twilight-zone and canopy shade induction of the Athb-2 homeobox gene in green plants. Proceedings of the National Academy of Sciences of the United States of America, vol. 93(8); p. 3530-3535


11-Aoyama T, Dong CH, Wu Y, Carabelli M, Sessa G, Ruberti I, Morelli G, Chua NH. (1995). Ectopic expression of the Arabidopsis transcriptional activator Athb-1 alters leaf cell fate in tobacco. Plant Cell, vol. 7(11); p. 1773-1785


12- Carabelli M, Sessa G, Baima S, Morelli G, Ruberti I. (1993). The Arabidopsis Athb-2 and -4 genes are strongly induced by far-red-rich light. Plant Journal, vol. 4(3); p. 469-479, 

Ida Ruberti, Giovanna Sessa – IBPM-CNR.

Marco Possenti, Giorgio Morelli - CREA-Centro di ricerca Alimenti e Nutrizione, Roma.

Laila Moubayidin, Lars Ostergaard – John Innes Centre, Norwich, Regno Unito.


Monica Carabelli has achieved the Master Degree in Biological Sciences in 1993, at the University of Rome La Sapienza. Has been research fellow at the Centro di Studio per gli Acidi Nucleici of CNR, Rome from 1993 to 1996. At this time, she has achieved the qualification for the profession of biologist. She was a Postdoctoral Fellow at the Rockefeller University, New York, USA, from 1996 to 1999. In 1999, the CNR has recognized her research activity abroad to be equivalent to the PhD title for internal contests. Subsequently, she has been a contractor for research activity at the National Institute for Nutrition, Rome, in 1999. In 2000, was recipient of a short-term EMBO fellowship at the Max-Plank-Institut for Plant Development in Cologne, Germany. Since 2000, she is exerting research activity first at the Centro di Studio per gli Acidi Nucleici of the CNR, later at the Institute for Molecular Biology and Pathology of CNR, Nucleic Acid Laboratory, Rome, starting as a

contractor and subsequently as researcher. 


1993 Award for best experimental thesis in the field of pasteurian disciplines of the “Foundation Instuitute Pasteur-Foundation Cenci-Bolognetti”  

1997 1997 SIBBM Award for the best 1996 publication in the field of Biophysics and Molecular Biology.

1998 Member of the Italian Society of Biochemistry.

1999 Member of the Italian Society of Biophysics and Molecular Biology.

2005 2005 SIGA award for best poster presented at the XLIX Annual Congress of the  Italian Society of Agricultural Genetics.