INFIVE   05416
INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
SASP, a Senescence-Associated Subtilisin Protease, is involved in reproductive development and determination of silique number in Arabidopsis
Autor/es:
DANA E MARTINEZ; MARIA L BORNIEGO; NATALIA BATTCHIKOVA; EVA-MARI ARO; ESA TYYSTJÄRVI; JUAN JOSE GUIAMÉT
Revista:
JOURNAL OF EXPERIMENTAL BOTANY
Editorial:
OXFORD UNIV PRESS
Referencias:
Lugar: Oxford; Año: 2015 vol. 66 p. 161 - 161
ISSN:
0022-0957
Resumen:
Senescence involves increased expression of proteases, which may participate in nitrogen recycling or cellular signalling. 2D zymograms detected two protein species with increased proteolytic activity in senescing leaves of Arabidopsis thaliana. A proteomic analysis revealed that both protein species correspond to a subtilisin protease encoded by At3g14067, termed Senescence-Associated Subtilisin Protease (SASP). SASP mRNA levels and enzyme activity increase during leaf senescence in leaves senescing during both the vegetative or the reproductive phase of the plant life cycle, but this increase is more pronounced in reproductive plants. SASP is expressed in all above-ground organs, but not in roots. Putative AtSASP orthologues were identified in dicot and monocot crop species. A phylogenetic analysis shows AtSASP and its putative orthologues clustering in one discrete group of subtilisin proteases in which no other Arabidospsissubtilisin protease is present. Phenotypic analysis of two knockout lines for SASPshowed that mutant plants develop more inflorescence branches during reproductive development. Both AtSASP and its putative rice orthologue (OsSASP) were constitutively expressed in sasp-1to complement the mutant phenotype. At maturity, sasp-1 plants produced 25% more inflorescence branches and siliques than either the wild-type or the rescued lines. These differences were mostly due to an increased number of second and third order branches. The increased number of siliques was compensated for by a small decrease (5.0%) in seed size.SASPdownregulates branching and silique production during monocarpic senescence, and its function is at least partially conserved between Arabidopsisand rice.
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