English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Syringomycin is a necrosis-inducing phytotoxin produced byPseudomonas syringae pv.syringae. To determine whether syringomycin production is a determinant in virulence or pathogenicity, we isolated nontoxigenic (Tox− ) Tn5 -containing mutants and then quantitatively evaluated them for the ability to multiply and cause disease in immature sweet-cherry fruits. Transposon Tn5 was delivered to Tox+ strain B301D-R by using the suicide vector, pGS9, and the resultant kanamycin-resistant (Kmr ) colonies were screened for changes in syringomycin production by testing for antibiosis againstGeotrichum candidum. Southern blot analysis ofKpn I-andEco RI-digested DNA showed that 15 (0.3%) Tox− mutants were isolated which had Tn5 inserted into 1 of 14 distinct loci. Phenotypic characterization of the Tox− mutants identified three major groups, which were differentiated by pathogenicity and ability to cause a tobacco hypersensitive reaction (HR). The eight strains in group A were pathogenic (Path+ ) in cherry fruit assays, but the disease index was 17 to 66% lower (significant atP = 0.01) than for the parental Tox+ strain, B301D-R. The population dynamics of group A strains W4S770 and W4S116 in cherry fruits were, however, indistinguishable from that of strain B301D-R. The remaining seven Tox− strains were nonpathogenic; group B strain W4S2545 (Path− HR+ ) and group C strain W4S468 (Path− HR− ) developed significantly lower populations (105 to 107 CFU per cherry fruit) 3 days after inoculation than strain B301D-R did (nearly 109 CFU per fruit). The data indicate that syringomycin is not essential for pathogenicity, but contributes significantly to virulence.

applied and environmental microbiology

Evaluation of the Role of Syringomycin in Plant Pathogenesis by Using Tn 5 Mutants of Pseudomonas syringae pv. syringae Defective in Syringomycin Production