Dual regulation of water retention and cell growth by a stress-associated protein (SAP) gene in Prunus.
We have identified a gene (PpSAP1) of Prunus persica coding for a stress-associated protein (SAP) containing Zn-finger domains A20 and AN1. SAPs have been described as regulators of the abiotic stress response in plant species, emerging as potential candidates for improvement of stress tolerance in plants. PpSAP1 was highly expressed in leaves and dormant buds, being down-regulated before bud dormancy release. PpSAP1 expression was moderately induced by water stresses and heat in buds. In addition, it was found that PpSAP1 strongly interacts with polyubiquitin proteins in the yeast two-hybrid system. The overexpression of PpSAP1 in transgenic plum plants led to alterations in leaf shape and an increase of water retention under drought stress. Moreover, we established that leaf morphological alterations were concomitant with a reduced cell size and down-regulation of genes involved in cell growth, such as GROWTH-REGULATING FACTOR (GRF)1-like, TONOPLAST INTRINSIC PROTEIN (TIP)-like, and TARGET OF RAPAMYCIN (TOR)-like. Especially, the inverse expression pattern of PpSAP1 and TOR-like in transgenic plum and peach buds suggests a role of PpSAP1 in cell expansion through the regulation of TOR pathway.
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain.
Alba
A
Lloret
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain.
Ana
A
Conejero
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain.
Carmen
C
Leida
Department of Plant Production, Instituto de Biotecnología Vegetal-Universidad Politécnita de Cartagena (IBV-UPCT), 30202, Cartagena, Murcia, Spain.
César
C
Petri
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain.
Francisco
F
Gil-Muñoz
Group of Fruit Tree Biotechnology, Department of Plant Breeding, CEBAS-CSIC, 30100, Murcia, Spain.
Lorenzo
L
Burgos
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain.
María Luisa
ML
Badenes
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113, Moncada, Valencia, Spain. rios_gab@gva.es.
Gabino
G
Ríos
D049109:Cell Proliferation; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D009997:Osmotic Pressure; D059828:Plant Cells / Q000502:physiology*; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D025821:Polyubiquitin / Q000378:metabolism; D025941:Protein Interaction Mapping; D000068239:Prunus persica / Q000235:genetics* / Q000502:physiology*; D020798:Two-Hybrid System Techniques; D014867:Water / Q000378:metabolism*
D010940:Plant Proteins; D014867:Water; D025821:Polyubiquitin