INVESTIGADORES
CONTI Gabriela
congresos y reuniones científicas
Título:
Transgenic Expression of Tobacco mosaic virus Capsid and Movement Proteins Modulate Plant Basal Defense and Biotic Stress Responses in Nicotiana tabacum
Autor/es:
GABRIELA CONTI; MARIA CECILIA RODRIGUEZ; CARLOS AUGUSTO MANACORDA; SEBASTIAN ASURMENDI
Lugar:
Kyoto
Reunión:
Congreso; XV International Congress of Molecular Plant Microbe Interactions; 2012
Institución organizadora:
International Society for Molecular Plant-Microbe Interactions
Resumen:
Plant viruses cause metabolic and physiological changes
associated with symptomatic disease phenotypes. Symptoms
involve direct and indirect effects, which result in disruption
of host physiology. We used transgenic tobacco expressing a
variant of Tobacco mosaic virus (TMV) coat protein (CPT42W)
or movement protein (MP), and a hybrid line (MP×CPT42W)
that coexpresses both proteins, to study the plant response
to individual viral proteins. Findings employing microarray
analysis of MP×CPT42W plants and silenced mp×cpT42W* controls
revealed that altered transcripts were mostly downregulated,
suggesting a persistent shut-off due to
MP×CPT42W expression. Next, we showed that MP triggered
reactive oxygen species (ROS) accumulation, reduction of
total ascorbate, and expression of ROS scavenging genes.
These effects were enhanced when both proteins were coexpressed.
MP and MP×CPT42W plants showed increased levels
of salicylic acid (SA) and SA-responsive gene expression.
Furthermore, these effects were partially reproduced in
Nicotiana benthamiana when GMP1 transcript was silenced.
CPT42W seems to be playing a negative role in the defense response
by reducing the expression of PR-1 and RDR-1. MP
and MP×CPT42W transgenic expression promoted a recoverylike
phenotype in TMV RNA infections and enhanced susceptibility
to Pseudomonas syringae and Sclerotinia sclerotiorum.
The individual effects of viral proteins may reflect the
ability of a virus to balance its own virulence.