Differential accumulation of mRNAs encoding extracellular and intracellular PR proteins in tomato induced by virulent and avirulent races of Cladosporium fulvum

Abstract

Tomato leaves infected by the fungal pathogen Cladosporium fulvum contain several types of intracellular and extracellular pathogenesis-related (PR) proteins. Previously, we reported the purification and serological characterization of five extracellular PR proteins: P2, P4, P6, a chitinase and a beta-1,3-glucanase [22, 23]. Here we describe the purification of a basic intracellular 33 kDa beta-1,3-glucanase and the isolation and characterization of cDNA clones encoding the two extracellular P14 isomers P4 and P6, the extracellular acidic beta-1,3-glucanase and a basic 35 kDa beta-1,3-glucanase, different from the purified 33 kDa protein. Southern blot analysis demonstrated that tomato PR proteins are not encoded by large gene families, as is the case in tobacco. The number of genes corresponding to each protein was estimated to vary between one and three. A northern blot analysis indicated that the mRNAs for the extracellular PR proteins (P4, P6 and acidic beta-1,3-glucanase) accumulate to similar levels in compatible and incompatible tomato-C. fulvum interactions, although the maximum level of expression is reached much faster in the incompatible interaction. On the other hand, the mRNA for the basic 35 kDa beta-1,3-glucanase is induced rapidly to high levels in both interactions, but declines in time to background levels only in the incompatible interaction. The relevance of this difference in relation to plant defence is discussed.

Response to Xanthomonas campestris pv.vesicatoria in Tomato Involves Regulation of Ethylene Receptor Gene Expression

“…4). A faster induction of PR genes also occurs during a hypersensitive response to other tomato pathogens such as Cladosporium fulvum (van Kan et al, 1992) and Pseudomonas syringae (Jia and Martin, 1999), as well as during several other incompatible plant-pathogen interactions (Linthorst, 1991). Therefore, response to X. campestris pv.…”

“…A 655-bp PCR fragment from a basic intracellular ␤-1,3-glucanase (GenBank accession no. M80608; van Kan et al, 1992) was amplified using the forward primer 5Ј-TCT-TGCCCCATTTCAACTTC and the reverse primer 3Ј-GTC-CCAAACTCTTTCAGACACC. The template for the basic intracellular chitinase (GenBank accession no.…”

Herbivore exploits orally secreted bacteria to suppress plant defenses

“…The cysteine proteinase inhibitor (CysPI) and polyphenol oxidase F/B (PPOF/B) were selected as JA-marker genes because they are well-established JA-inducible proteins that function against CPBs (19)(20)(21). For an SA-marker gene, pathogenesis-related 1 (PR-1(P4)) was selected (22). Feeding by untreated larvae decreased expression levels of the JAresponsive CysPI and PPOF/B compared with feeding by ABtreated larvae, whereas feeding by untreated larvae increased SA-responsive PR-1(P4) expression (Fig.…”

Metabolic fingerprinting of Tomato Mosaic Virus infected Solanum lycopersicum

“…Although differing in the speed of the response to the pathogens, incompatible and compatible interactions share very similar general and common features, such as the induction of the plant signalling compounds, such as salicylic acid (SA; 2-75 hydroxybenzoic acid) (Sticher et al, 1997;Vlot et al, 2009) and ethylene, and the synthesis of pathogenesis-defence proteins (van Kan et al, 1992;van Loon et al, 2006).…”