Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Improving Stress and Disease Resistance in Tree Fruit Crops

Location: Appalachian Fruit Research Laboratory

Title: De-novo assembly and characterization of the transcriptome of Metschnikowia fructicola reveals differences in gene expression following interaction with Penicillium digitatum and grapefruit peel

Authors
item Hershkovitz, Vera -
item Sela, Noa -
item Tah-Salaime, Leena -
item Liu, Jia -
item Rafael, Ginat -
item Kessler, Clarita -
item Aly, Radi -
item Levi, Maggie -
item Wisniewski, Michael
item Droby, Samir -

Submitted to: Biomed Central (BMC) Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 12, 2013
Publication Date: August 5, 2013
Citation: Hershkovitz, V., Sela, N., Tah-Salaime, L., Liu, J., Rafael, G., Kessler, C., Aly, R., Levi, M., Wisniewski, M.E., Droby, S. 2013. De-novo assembly and characterization of the transcriptome of Metschnikowia fructicola reveals differences in gene expression following interaction with Penicillium digitatum and grapefruit peel. Biomed Central (BMC) Genomics. p. 1-13.

Interpretive Summary: Developing alternative approaches to disease control is a critical objective of NP-303, Plant Diseases, due to consumer demands to lower exposure to chemicals, and to reduce the impact of agriculture on the environment. In the past decade, USDA-ARS has identified several species of yeasts that can be used as biocontrol agents against postharvest diseases of fruit. Understanding the biology of the interaction between yeast antagonists, postharvest decay pathogens, and host tissues (harvested fruit) is essential to improving the use of identified yeast antagonists used for postharvest decay control and identifying superior new biocontrol agents. In the present study, as part of a collaborative project with ARO, Israel, new high-throughput gene sequencing technology (RNA-Seq) was used to identify yeast genes that were expressed by the yeast antagonist, Metschnikowia fructicola, during its interaction with the postharvest, Penicillium digitatum (green mold), and with citrus fruit. More than 26 million sequencing reads were assembled into 9,674 unique genes. Approximately 50 percent of these genes could be functionally identified based on their homology to genes present public databases. An analysis of differential expression when the yeast was interacting with the fruit vs. the pathogen revealed more than 250 genes with specific expression responses. In the antagonist-pathogen interaction, genes related to transmembrane, multidrug transport, and to protein metabolism were induced. In the antagonist-fruit interaction, expression of genes involved in oxidative stress, iron homeostasis, zinc homeostasis, and lipid metabolism were induced. This study provides new insight into the biology of the tritrophic interactions that occur in a biocontrol system such as the use of the yeast, M. fructicola, for the control of green mold on citrus caused by P. digitatum. The information will be utilized to examine the functional role of specific genes in biocontrol activity and induced disease resistance in harvested fruits.

Technical Abstract: The yeast, Metschnikowia fructicola, is an antagonist with biological control activity against postharvest diseases of several fruits. We performed a transcriptome analysis, using RNA-Seq technology, to examine the response of M. fructicola with citrus fruit and with the postharvest pathogen, Penicillium digitatum. More than 26 million sequencing reads were assembled into 9,674 unigenes. Approximately 50 percent of the unigenes could be annotated based on homology matches in the NCBI database. Based on homology, sequences were annotated with a gene description, gene ontology (GO term), and clustered into functional groups. An analysis of differential expression when the yeast was interacting with the fruit vs. the pathogen revealed more than 250 genes with specific expression responses. In the antagonist-pathogen interaction, genes related to transmembrane, multidrug transport, and to amino acid metabolism were induced. In the antagonist-fruit interaction, expression of genes involved in oxidative stress, iron homeostasis, zinc homeostasis, and lipid metabolism were induced. Patterns of gene expression in the two interactions were examined at the individual transcript level by quantitative real-time PCR analysis (RT-qPCR). This study provides new insight into the biology of the tritrophic interactions that occur in a biocontrol system such as the use of the yeast, M. fructicola, for the control of green mold on citrus caused by P. digitatum.

Last Modified: 10/23/2014
Footer Content Back to Top of Page