Proteomic analysis of pathogenesis-related proteins (PRs) induced by compatible and incompatible interactions of pepper mild mottle virus (PMMoV) in Capsicum chinense L³ plants

• Published in: Journal of experimental botany Vol. 59; no. 6; pp. 1253 - 1265
• Main Authors: Elvira, Maria Isabel, Galdeano, Myriam Molina, Gilardi, Patricia, García-Luque, Isabel, Serra, Maria Teresa
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 2008
• Subjects: Amino Acid Sequence; Biological and medical sciences; Capsicum - genetics; Capsicum - physiology; Capsicum - virology; Capsicum chinense; chitinase; Cloning, Molecular; compatible interaction; disease resistance; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Profiling - methods; Generalities. Disease free stocks; genes; Host-Pathogen Interactions; hosts; HR-induction; hypersensitive response; incompatible interaction; Kinetics; leaves; lesions (plant); messenger RNA; Molecular Sequence Data; nucleotide sequences; pathogenesis-related proteins; Pepper mild mottle virus; peroxidases; physiological state; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - virology; Plant Leaves - physiology; Plant Leaves - virology; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified; PMMoV; PR proteins; protein isoforms; Protein Isoforms - chemistry; Protein Isoforms - genetics; Protein Isoforms - metabolism; protein synthesis; proteome; Proteomics; RNA, Plant - chemistry; RNA, Plant - metabolism; RNA, Viral - metabolism; Sequence Homology, Amino Acid; Tobamovirus - physiology; Dicotyledones; compatible interaction; Angiospermae; Proteomics; Capsicum chinense; Spermatophyta; Solanaceae; Pathogenesis related protein; PMMoV; PR proteins; HR-induction; incompatible interaction
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ern032

Resistance conferred by the L³ gene is active against most of the tobamoviruses, including the Spanish strain (PMMoV-S), a P₁,₂ pathotype, but not against certain strains of pepper mild mottle virus (PMMoV), termed P₁,₂,₃ pathotype, such as the Italian strain (PMMoV-I). Both viruses are nearly identical at their nucleotide sequence level (98%) and were used to challenge Capsicum chinense PI159236 plants harbouring the L³ gene in order to carry out a comparative proteomic analysis of PR proteins induced in this host in response to infection by either PMMoV-S or PMMoV-I. PMMoV-S induces a hypersensitive reaction (HR) in C. chinense PI159236 plant leaves with the formation of necrotic local lesions and restriction of the virus at the primary infection sites. In this paper, C. chinense PR protein isoforms belonging to the PR-1, β-1,3-glucanases (PR-2), chitinases (PR-3), osmotin-like protein (PR-5), peroxidases (PR-9), germin-like protein (PR-16), and PRp27 (PR-17) have been identified. Three of these PR protein isoforms were specifically induced during PMMoV-S-activation of C. chinense L³ gene-mediated resistance: an acidic β-1,3-glucanase isoform (PR-2) (Mr 44.6; pI 5.1), an osmotin-like protein (PR-5) (Mr 26.8; pI 7.5), and a basic PR-1 protein isoform (Mr 18; pI 9.4-10.0). In addition, evidence is presented for a differential accumulation of C. chinense PR proteins and mRNAs in the compatible (PMMoV-I)-C. chinense and incompatible (PMMoV-S)-C. chinense interactions for proteins belonging to all PR proteins detected. Except for an acidic chitinase (PR-3) (Mr 30.2; pI 5.0), an earlier and higher accumulation of PR proteins and mRNAs was detected in plants associated with HR induction. Furthermore, the accumulation rates of PR proteins and mRNA did not correlate with maximal accumulation levels of viral RNA, thus indicating that PR protein expression may reflect the physiological status of the plant.