Special Session: The Complicated Lifestyles of Dothideomycete Fungi: Understanding Novel Mechanisms of Pathogenicity

41-S

Molecular dissection of stomatal infection in Cercospora zeae-maydis.
B. BLUHM (1)
(1) University of Arkansas, Fayetteville, AR, U.S.A.

Cercospora zeae-maydis causes gray leaf spot, a ubiquitous and potentially devastating disease of maize. During pathogenesis, C. zeae-maydis senses and grows towards host stomata, followed by a latent, hemi-biotrophic phase preceding the induction of necrosis. To understand the molecular basis of infection in C. zeae-maydis, we employed a combination of techniques in molecular genetics and functional genomics. Recently, we established a genetic linkage between light sensing, the circadian clock of C. zeae-maydis, and stomatal perception. Additionally, we identified putative regulators of stomatal infection through a forward genetic screen combined with differential expression profiling via RNA-seq. Furthermore, we are utilizing comparative genomics to identify putative regulators of pathogenesis in C. zeae-maydis. To this end, we recently obtained draft genome sequences for C. zeina (a sibling species of C. zeae-maydis that also causes gray leaf spot of maize), C. sojina (causes frogeye leaf spot of soybean), and C. kikuchii (causes Cercospora leaf blight of soybean). Of particular interest are genes undergoing diversifying selection, displaying interesting presence/absence patterns, or are unique at the genus or species level. Although many questions remain to be answered, findings to date have increased the understanding of stomatal infection and led to the formulation of new hypotheses regarding pathogenesis in C. zeae-maydis.