Journal
PHYTOPATHOLOGY
Volume 102, Issue 8, Pages 741-748Publisher
AMER PHYTOPATHOLOGICAL SOC
DOI: 10.1094/PHYTO-02-12-0021-R
Keywords
-
Categories
Funding
- Ministry of Education, Culture, Sports, Science, and Technology of Japan
- Japan Science and Technology Agency
Ask authors/readers for more resources
The rough lemon pathotype of Alternuria ulternata produces hostselective ACR-toxin and causes Alternaria leaf spot disease of the rootstock species rough lemon (Citrus jumbhiri) and Rangpur lime (C. limonia). Genes controlling toxin production were localized to a I.5-Mb chromosome carrying the ACR-toxin biosynthesis gene cluster (ACR7) in the genorne of the rough lemon pathotype. A genomic BAC clone containing a portion of the ACRT cluster was sequenced which allowed identification of three open reading frames present only in the genomes of ACR-toxin producing isolates. We studied the functional role of one of these open reading frames, ACRTS1 encoding a putative hydroxylase, in ACR-toxin production by homologous recombination-mediated gene disruption. There are at least three copies of ACRTSI gene in the genome and disruption of two copies of this gene significantly reduced ACR-toxin production as well as pathogenicity; however, transcription of ACRTS1 and production of ACR-toxin were not completely eliminated due to remaining functional copies of the gene. RNA-silencing was used to knock down the remaining ACRTS1 transcripts to levels undetectable by reverse transcription-polymerase chain reaction. The silenced transformants did not produce detectable ACR-toxin and were not pathogenic. These results indicate that ACRTS1 is an essential gene in ACR-toxin biosynthesis in the rough lemon pathotype of A. alternata and is required for full virulence of this fungus.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available