Photosynthetic responses of lettuce to downy mildew infection and cytokinin treatment
Language English Country France Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
20471849
DOI
10.1016/j.plaphy.2010.04.003
PII: S0981-9428(10)00081-1
Knihovny.cz E-resources
- MeSH
- Benzyl Compounds pharmacology MeSH
- Chlorophyll chemistry metabolism MeSH
- Chloroplasts metabolism ultrastructure MeSH
- Cytokinins pharmacology MeSH
- Fluorescence MeSH
- Photosynthesis drug effects MeSH
- Photosystem II Protein Complex chemistry metabolism MeSH
- Host-Pathogen Interactions MeSH
- Plant Leaves metabolism microbiology physiology MeSH
- Plant Diseases microbiology MeSH
- Oomycetes physiology MeSH
- Purines pharmacology MeSH
- Plant Growth Regulators pharmacology MeSH
- Lactuca metabolism microbiology physiology MeSH
- Microscopy, Electron, Transmission MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- benzylaminopurine MeSH Browser
- Benzyl Compounds MeSH
- Chlorophyll MeSH
- Cytokinins MeSH
- Photosystem II Protein Complex MeSH
- Purines MeSH
- Plant Growth Regulators MeSH
Changes in primary metabolism of lettuce, Lactuca sativa L. (cv. Cobham Green), induced by compatible interaction with the biotrophic oomycete pathogen Bremia lactucae Regel (race BL 16), under two intensities of illumination in the presence and absence of exogenous cytokinins were studied by chlorophyll fluorescence imaging. Thirteen days post-inoculation leaf discs infected by B. lactucae exhibited impairments of photosynthesis associated with biotrophic infections, including: reductions in photosynthetic pigment contents and the maximum quantum yield of photosystem II photochemistry (F(V)/F(M)), inhibition of electron transport (Phi(PSII)) and increased non-photochemical chlorophyll fluorescence quenching (NPQ). Detected changes in photosynthetic parameters correlated with the leaf area colonized by the pathogen's intercellular hyphae. Applications of two cytokinins, benzylaminopurine and meta-topolin, previously shown to suppress B. lactucae sporulation if applied 24 h prior to inoculation at a concentration of 200 microM, retarded the pathogen's asexual reproduction with no apparent negative effects on the host's photosynthetic apparatus. However, long-lasting treatment of healthy tissues with this high concentration of exogenous cytokinin led to effects parallel to pathogenesis: reductions in photosynthetic pigment contents accompanied by inhibition of photosystem II photochemistry and electron transport. These effects of both prolonged exposure to cytokinins and the pathogenesis were weaker in discs exposed to the lower photosynthetic photon flux density. The role of cytokinins in plant-biotrophic pathogen interactions and their potential as disease control agents are discussed.
References provided by Crossref.org
Role of Cytokinins in Senescence, Antioxidant Defence and Photosynthesis
High cytokinin levels induce a hypersensitive-like response in tobacco
