Is Salicylic Acid a Translocated Signal of Systemic Acquired Resistance in Tobacco?
AUTOR(ES)
Shulaev, V
RESUMO
Salicylic acid (SA) is a likely endogenous signal in the development of systemic acquired resistance (SAR) in some dicotyledonous plants. In tobacco mosaic virus (TMV)-resistant Xanthi-nc tobacco, SA levels increase systemically following the inoculation of a single leaf with TMV. To determine the extent to which systemic increases in SA result from SA export from the inoculated leaf, SA produced in TMV-inoculated or healthy leaves was noninvasively labeled with 18O2. Spatial and temporal distribution of 18O-SA indicated that most of the SA detected in the healthy tissues was synthesized in the inoculated leaf. No significant increase in the activity of benzoic acid 2-hydroxylase, the last enzyme involved in SA biosynthesis, was detected in upper uninoculated leaves, although the basal level of enzyme activity was relatively high. No increases in SA level, pathogenesis-related PR-1 gene expression, or TMV resistance in the upper uninoculated leaf were observed if the TMV-inoculated leaf was detached up to 60 hr after inoculation. Apart from the inoculated tissues, the highest increase in SA was observed in the leaf located directly above the inoculated leaf. The systemic SA increase observed during SAR may be explained by phloem transport of SA from the inoculation sites.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=161030Documentos Relacionados
- Salicylic Acid Is Not the Translocated Signal Responsible for Inducing Systemic Acquired Resistance but Is Required in Signal Transduction.
- Local and Systemic Responses of Antioxidants to Tobacco Mosaic Virus Infection and to Salicylic Acid in Tobacco (Role in Systemic Acquired Resistance).
- Salicylic acid is a systemic signal and an inducer of pathogenesis-related proteins in virus-infected tobacco.
- Signal transduction in systemic acquired resistance.
- A New Twist on Systemic Acquired Resistance: Redox Control of the NPR1–TGA1 Interaction by Salicylic Acid