Effect of ammonia production by Colletotrichum gloeosporioides on pelB activation, pectate lyase secretion, and fruit pathogenicity.

ABSTRACT: The accumulation of ammonia and associated tissue alkalinization predispose avocado fruit to attack by Colletotrichum gloeosporioides. Secretion of ammonia by C. gloeosporioides in the presence of KNO3 was induced by decreasing the pH from 7.0 to 4.0. When the fungus was grown at pH 4.0 or 6.0 in the absence of a nitrogen source, ammonia did not accumulate, and neither pelB (encoding pectate lyase) transcription nor pectate lyase secretion was detected. Under these nitrogen starvation conditions, only transcriptional activation of areA, which encodes the global nitrogen regulator, was detected. pelB transcription and pectate lyase secretion were both detected when C. gloeosporioides was grown at pH 6.0 in the presence of ammonia accumulated from different nitrogen sources. The early accumu

SUBMITTER: Kramer-Haimovich H 

PROVIDER: S-EPMC1392887 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature