GAIA BERTOLOTTI

Dottoressa di ricerca

ciclo: XXXIV



Titolo della tesi: ASYMMETRIC CELL DIVISIONS: AN EVOLUTIONARY DEVELOPMENTAL ROADMAP TO DEFINE ROOT DIVERSITY

Asymmetric cell division is a most successful strategy in multicellular organisms to generate cell diversity. How the regulation of asymmetric cell division generate intraspecific and interspecific patterning diversity is however still unclear. In this regards, I identified the ground tissue (GT) as an optimal model to clarify the role of asymmetric cell division in controlling root patterning in plants. The GT is formed by endodermis and cortex(es), and its patterning varies in individuals and/or among different plant species; in particular the number of cortical layers can vary from one to several depending on the species and the age of plants. In my studies I utilize two close relative model systems A.thaliana, and C.hirsuta to shed light on the molecular mechanisms governing ACDs responsible of cortical layer number formation. By means of molecular and genetic analysis I demonstrate that HOMEODOMAIN LEUCINE ZIPPER III (HD-ZIPIII) transcription factor PHABULOSA (PHB) is a master regulator of multiple cortical layer formation as this transcription factor triggers ACDs. In detail, I show two different molecular mechanisms regulated by PHB: 1. In A.thaliana, during post-embryonic maturation, in a time window spanning from 7 to 14 days post germination (dpg), a second cortical layer, namely the Middle Cortex (MC), is generated by asymmetric cell divisions in the endodermis of about 80% of primary roots. Here, I show that vascular PHB activity mediates the expression of the cell cycle regulator CYCD6;1 in the endodermis. In particular PHB control the homeostasis of the plant hormone gibberellin GA catabolic promoting GIBBERELLIN 2 OXIDASE 2 (GA2ox2) in the vascular tissue. 2. In C.hirsuta a set of cells with both cortex and endodermis identity (CEMs) divides asymmetrically, generating two cortical and one endodermal layers. I demonstrate that the activity of PHB in CEMs is fundamental for regulating this ACD, prompting the formation of multiple cortical layers. In particular, I show that in C.hirsuta PHB triggers periclinal cell divisions in those cells promoting the expression of CYCD6,1 via the phytohormone cytokinin (CKs). My studies reveal for the first time a role of PHB as master regulator of GT ACDs.

Produzione scientifica

11573/1688737 - 2023 - microRNA165 and 166 modulate response of the Arabidopsis root apical meristem to salt stress
Scintu, Daria; Scacchi, Emanuele; Cazzaniga, Francesca; Vinciarelli, Federico; De Vivo, Mirko; Shtin, Margaryta; Svolacchia, Noemi; Bertolotti, Gaia; Unterholzner, Simon Josef; Del Bianco, Marta; Timmermans, Marja; Di Mambro, Riccardo; Vittorioso, Paola; Sabatini, Sabrina; Costantino, Paolo; Dello Ioio, Raffaele - 01a Articolo in rivista
rivista: COMMUNICATIONS BIOLOGY ([London]: Springer Nature) pp. - - issn: 2399-3642 - wos: WOS:001048568700001 (2) - scopus: 2-s2.0-85167740002 (1)

11573/1668591 - 2023 - The mutual inhibition between PLETHORAs and ARABIDOPSIS RESPONSE REGULATORs controls root zonation
Shtin, Margaryta; Polverari, Laura; Svolacchia, Noemi; Bertolotti, Gaia; Unterholzner, Simon J; Mambro, Riccardo Di; Costantino, Paolo; Ioio, Raffaele Dello; Sabatini, Sabrina - 01a Articolo in rivista
rivista: PLANT AND CELL PHYSIOLOGY (Oxford University Press:Journals Department, Great Clarendon Street, Oxford OX2 6DP United Kingdom:011 44 1865 556767, EMAIL: jnlorders@oup.co.uk, INTERNET: http://www.oup.co.uk, Fax: 011 44 1865 267485) pp. - - issn: 0032-0781 - wos: WOS:000932131300001 (2) - scopus: 2-s2.0-85150396530 (2)

11573/1567287 - 2021 - A small cog in a large wheel: crucial role of miRNAs in root apical meristem patterning
Bertolotti, G; Scintu, D; Dello Ioio, R - 01g Articolo di rassegna (Review)
rivista: JOURNAL OF EXPERIMENTAL BOTANY (Oxford University Press:Journals Department, Great Clarendon Street, Oxford OX2 6DP United Kingdom:011 44 1865 556767, EMAIL: jnlorders@oup.co.uk, INTERNET: http://www.oup.co.uk, Fax: 011 44 1865 267485) pp. - - issn: 0022-0957 - wos: WOS:000711239100009 (5) - scopus: 2-s2.0-85118944767 (7)

11573/1454974 - 2020 - A PHABULOSA-controlled genetic pathway regulates ground tissue patterning in the Arabidopsis root
Bertolotti, Gaia; Unterholzner, Simon Josef; Scintu, Daria; Salvi, Elena; Svolacchia, Noemi; Di Mambro, Riccardo; Ruta, Veronica; Linhares Scaglia, Francisco; Vittorioso, Paola; Sabatini, Sabrina; Costantino, Paolo; Dello Ioio, Raffaele - 01a Articolo in rivista
rivista: CURRENT BIOLOGY (Current Biology Limited:84 Theobalds Road, London WC1X 8RR United Kingdom:011 44 20 76114202, EMAIL: info@biomednet.com, INTERNET: http://www.biomednet.com, Fax: 011 44 20 76114479) pp. - - issn: 0960-9822 - wos: WOS:000631966000008 (14) - scopus: 2-s2.0-85097093740 (16)

11573/1275762 - 2019 - Cytokinin-Dependent Control of GH3 Group II Family Genes in the Arabidopsis Root
Pierdonati, Emanuela; Unterholzner, Simon Josef; Salvi, Elena; Svolacchia, Noemi; Bertolotti, Gaia; Dello Ioio, Raffaele; Sabatini, Sabrina; Di Mambro, Riccardo - 01a Articolo in rivista
rivista: PLANTS (Basel: MDPI) pp. - - issn: 2223-7747 - wos: WOS:000467296200017 (28) - scopus: 2-s2.0-85065082661 (29)

11573/1025084 - 2018 - Differential spatial distribution of miR165/6 determines variability in plant root anatomy
Giovanna Di Ruocco, ; Bertolotti, Gaia; Pacifici, Elena; Polverari, Laura; Miltos, Tsiantis; Sabatini, Sabrina; Costantino, Paolo; Dello Ioio, Raffaele - 01a Articolo in rivista
rivista: DEVELOPMENT (The Company of Biologists Limited:Bidder Building, 140 Cowley Road, Cambridge CB4 0DL United Kingdom:011 44 1223 420482, EMAIL: mandy@thecob.demon.co.uk, INTERNET: http://www.biologists.com, Fax: 011 44 1223 423353) pp. - - issn: 0950-1991 - wos: WOS:000423820200009 (20) - scopus: 2-s2.0-85040778911 (21)

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