Identification and characterization of the members of the pho1 gene family in moss and rice

Détails

Ressource 1Télécharger: BIB_6D9A31117CEB.P001.pdf (25406.43 [Ko])
Etat: Supprimée
Version: Après imprimatur
ID Serval
serval:BIB_6D9A31117CEB
Type
Thèse: thèse de doctorat.
Collection
Publications
Institution
Titre
Identification and characterization of the members of the pho1 gene family in moss and rice
Auteur⸱e⸱s
Secco D.
Directeur⸱rice⸱s
Poirier Y.
Détails de l'institution
Université de Lausanne, Faculté de biologie et médecine
Statut éditorial
Acceptée
Date de publication
12/2010
Langue
anglais
Nombre de pages
161
Résumé
Inorganic phosphate (Pi) is one of the main nutrients limiting plant growth anddevelopment in many agro-ecosystems. In plants, phosphate is acquired from the soil by theroots, and is then transferred to the shoot via the xylem. In the model plant Arabidopsisthaliana, PHO1 was previously identified as being involved in loading Pi into the xylem ofroots. AtPHO1, belongs to a multigenic family composed of 10 additional members, namelyAtPHO1;H1 to AtPHO1;10. In this study, we aimed at further investigating the role of thePHO1 gene family in Pi homeostasis in plants, and to this end we isolated and characterizedthe PHO1 members of two main model plants, the moss Physcomitrella patens and the riceOryza sativa.In the bryophyte P. patens, bioinformatic analyses revealed the presence of seven AtPHO1homologues, highly similar to AtPHO1. The seven moss PHO1 genes, namely PpPHO1;1 toPpPHO1;7 appeared to be differentially regulated, both at the tissue level and in response toPi status. However only PpPHO1;1 and PpPHO1;7 were specifically up-regulated upon Pistarvation, suggesting a potential role in Pi homeostasis. We also characterized the responseof P. patens to Pi starvation, showing that higher and lower plants share some commonstrategies to adapt to Pi-deficiency.In the second part, focusing on the monocotyledon rice, we showed the existence of threePHO1 homologues OsPHO1;1 to OsPHO1;3, with the unique particularity of each havingNatural Antisense Transcripts (NATs). Molecular analyses revealed that both the sense andthe antisense OsPHO1;2 transcripts were by far the most abundantly expressed transcripts ofthe family, preferentially expressed in the roots. The stable expression of OsPHO1;2 in allconditions tested, in opposition with the highly induced antisense transcript upon Pistarvation, suggest a putative role for the antisense in regulating the sense transcript.Moreover, mutant analyses revealed that OsPHO1;2 plays a key role in Pi homeostasis, intransferring Pi from the root to the shoot. Finally, complementing the pho1 mutant inArabidopsis, characterized by low Pi in the shoot and reduced growth, with the riceOsPHO1;2 gene revealed a new role for PHO1 in Pi signaling. Indeed, the complementedplants showed normal growth, with however low Pi content.
Création de la notice
02/12/2010 13:28
Dernière modification de la notice
20/08/2019 14:27
Données d'usage