Transcriptome of Colletotrichum graminicola wild-type and and mutant isolates during infection of Zea mays leaf sheaths

ABSTRACT: Colletotrichum graminicola is a hemibiotrophic fungal pathogen that causes maize anthracnose disease. It progresses through three recognizable phases of pathogenic development *in planta*: melanized appressoria that form on the host surface prior to penetration; biotrophy, characterized by colonization of living host cells; and necrotrophy, characterized by host cell death and symptom development. An improved filtering algorithm and a Mixed Effects Generalized Linear Model (GLM) were developed and applied to an existing Illumina transcriptome dataset, substantially increasing the statistical power of the analysis of *C. graminicola* gene expression during infection and colonization. Additionally, the *in planta* transcriptome of the wild-type was compared with that of a mutant strain impaired in the establishment of biotrophy, allowing detailed dissection of events occurring specifically during penetration, and during early versus late biotrophy. Results indicated that there is a continuum of activities that occur during colonization of maize by *C. graminicola*, and that boundaries drawn between the three recognizable phases are artificial. More than 2000 fungal genes were differentially transcribed in waves during appressorial maturation, penetration, and colonization. Secreted proteins and membrane receptors were over-represented among the differentially expressed genes, suggesting that the fungus engages in an intimate and dynamic conversation with the host, beginning prior to penetration. This communication process is likely to involve reception of plant signals that trigger subsequent developmental progress in the fungus, as well as the production of signals that induce responses in the host. Later phases of biotrophy were more similar to necrotrophy, with increased production of secreted proteases, inducers of plant cell death, hydrolases, and membrane bound transporters for the uptake and egress of potential toxins, signals, and nutrients. The differentially expressed genes could be used as landmarks to more accurately identify developmental progress in compatible versus incompatible interactions involving genetic variants of both host and pathogen.

ORGANISM(S): Colletotrichum graminicola

PROVIDER: GSE71919 | GEO | 2016/03/17

SECONDARY ACCESSION(S): PRJNA293991

REPOSITORIES: GEO