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Characterization of potato tuber lipoxygenase cDNAs and lipoxygenase expression in potato tubers and leaves
Author(s) -
Fidantsef Ana L.,
Bostock Richard M.
Publication year - 1998
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.1998.1020214.x
Subject(s) - jasmonic acid , biology , complementary dna , solanum tuberosum , lipoxygenase , jasmonate , microbiology and biotechnology , potato virus x , methyl jasmonate , phytophthora infestans , biochemistry , elicitor , molecular mass , gene , enzyme , rna , botany , arabidopsis , mutant
A collection of cDNAs was isolated from a λgt11 potato ( Solanum tuberosum L.) tuber library by using a soybean lipoxygenase (LOX; linoleate:oxygen oxidoreductase, EC 1.13.11.12) sequence as a hybridization probe. These cDNA clones were classified by restriction patterns and sizes and two clones, plox 1 and plox 2, were selected for sequencing and further analysis. These clones were found to be virtually identical and contain full‐length cDNAs having a high degree of homology with other cloned LOX genes. plox 1 contains a 2 806‐bp insert, with an open reading frame that encodes a protein of 861 amino acids (96.9 kDa), consistent with molecular mass estimates of the principal tuber LOX deduced from SDS‐PAGE. The deduced sequence contains iron‐binding domains that are conserved among LOXs. Restriction analysis of potato genomic DNA confirmed that potato LOX is comprised of a gene family with at least three members. The plox 1 sequence hybridized to a transcript of 2.8 kb in gel blot analyses of total RNA extracted from potato tuber. Treatment of potato disks and leaves with methyl jasmonate or jasmonic acid increased LOX enzyme activity, as well as abundance of LOX mRNA, consistent with jasmonate's reported effect on LOX expression in plants. The fungal elicitor arachidonic acid (AA) strongly induced LOX enzyme activity in leaves and induced LOX mRNA transcripts in potato leaves and tuber disks. Infection of potato leaves with Phytophthora infestans induced LOX activity as well as LOX mRNA accumulation in both incompatible and compatible interaction types. LOX expression was compared with that of a wound‐inducible proteinase inhibitor (PINII) and a pathogenesis‐related protein (P4). Jasmonates induced PINII but not P4 transcript accumulation in potato leaves. In contrast, AA induced P4 but not PINII transcript accumulation in potato leaves. Infection with P. infestans resulted in a gene expression pattern similar to that observed with AA.