Differential accumulation of potato tuber mRNAs during the hypersensitive response induced by arachidonic acid elicitor.

Accumulation of messenger RNAs in potato tuber discs was analysed during the hypersensitive response induced by treatment with the biotic elicitor arachidonic acid. In vitro translation of polysomal poly(A)(+) RNAs indicated that the accumulation of some sixteen mRNAs varied following treatment with arachidonic acid, and that the level of thirteen of these was increased. Two cDNA closes (pSTH-1 and-2) were isolated from a library of elicitor-treated tissue cDNAs. Northern blot analysis using these clones as molecular probes indicated that the levels of at least two mRNAs were markedly increased after elicitor treatment. In hybrid-released translation experiments, each of the cDNA clones selected more than one mRNA. Translation of these mRNAs yielded two polypeptides of Mr 45 000 (for the pSTH-1 clone), and three polypeptides of Me 17 000 (for the pSTH-2 clone). The low molecular weight polypeptides may correspond to potato pathogenesis-related (PR) proteins.