FIG 7.

Thioredoxin- and glutaredoxin-coding genes are required for A. alternata pathogenicity. Pathogenicity was assayed on detached Ponkan leaves by placing a 5- by 5-mm agar plug covering fungal mycelium on the tops of the leaves. The wild-type strain (Z7), the Δtsa1 strain with impaired thioredoxin peroxidase, the CPTsa1 strain expressing a copy of AaTsa1, the Δtrr1 strain with impaired thioredoxin reductase, the CPTrr1 strain expressing a copy of AaTrr1, and the Δglr1 strain with impaired glutathione reductase were grown on PDA, and agar plugs were cut with a sterile toothpick. The leaves were incubated in a plastic box for lesion development. Development of necrotic lesions on detached citrus leaves was observed at 2 days postinoculation (dpi). Only some representative replicates are shown. The percent changes of necrotic lesions appearing on the bottoms of the leaves calculated in relation to those induced by the wild-type strain Z7 are also indicated.