|Laraba, Imane - Orise Fellow|
|Aime, Catherine - Purdue University|
|Wurdack, Kenneth - Smithsonian Institute|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2019
Publication Date: 3/17/2019
Citation: Laraba, I., Kim, H.-S., Vaughan, M.M., Busman, M., Proctor, R., O'Donnell, K., Aime, C.M., Wurdack, K.J. 2019. A novel Fusarium induces putative pseudoflowers on yellow-eyed grass (Xyris spp.) in Guyana [abstract].
Technical Abstract: We discovered and characterized a novel Fusarium species that appears to induce putative pseudoflowers on two species of yellow-eyed grass in the remote Cuyuni-Mararuni Region of Guyana. A species-specific PCR assay showed that the fungus had established a systemic infection in plants that were not producing true flowers. Instead infected plants formed a rosette of ultraviolet reflective petaloid structures that mimic host flowers in color, shape and size. Results of a PCR assay for MAT idiomorph revealed that single microconidial isolates from the flower-like rosettes on Xyris surinaminsis and X. setigera were MAT1-1 and MAT1-2, respectively. We speculate that this heterothallic fungus is tricking an unknown plant pollinator into vectoring microconidia of mating compatible strains to the same host plant. Multilocus molecular phylogenetic data mined from whole genome sequences resolved the novel Fusarium pathogen as a member of the African clade of the F. fujikuroi species complex. The potential of the pathogen to produce biologically active compounds, including phytohormones, pigments and mycotoxins, was assessed by conducing BLASTn searches of whole genome sequence data, via gene expression analyses of hormone biosynthetic genes in liquid culture and by liquid chromatography-mass spectrometric analyses of strains cultured on cracked corn. The Xyris pathogen is phenotypically distinct from all other Fusarium species in that it produces abundant erect microconidia-bearing synnemata up to 2 mm in length on carnation leaves.