Biology subjects

Kazan, K.

Publications and source records attributed to Kazan, K..

4 recordsLinked to original sources

bioRxiv2021

Translational control of fungal gene expression during the wheat-Fusarium graminearum interaction

O_LITo date, translational regulation of key genes controlling infection-related processes in fungal pathogens during their interactions with plants has not been studied. Here, we employed ribosome profiling (ribo-seq) to study translational responses and how such responses are coordinated with transcriptional changes in the fungal pathogen Fusarium graminearum (Fg), which causes Fusarium head blight (FHB), a destructive disease of cereal crops worldwide. C_LIO_LITranscription and translation were not always coordinated with approximately 22% of Fg genes showing a discordant relationship during wheat infection. Nitrite reductase, which we show here as an important component of fungal virulence, is only regulated at the translational level in Fg. In addition, more than 1000 new open reading frames (ORFs), many of which are short and highly conserved, were identified in the Fg genome. C_LIO_LILike in higher eukaryotes, translation is controlled by upstream ORFs (uORFs) in Fg during infection. Similarly, miRNAs control both transcription and translation in Fg during wheat infection. However, Fgdicer2-dependent miRNAs do not have a significant effect on transcriptional gene expression at the global outset. C_LIO_LIThe ribo-seq study undertaken here for the first time in any fungal pathogen discovered novel insights about the biology of an important plant pathogen. C_LI

pathology↗

bioRxiv2020

Transcriptome analysis reveals infection strategies employed by Fusarium graminearum as a root pathogen

The fungal pathogen Fusarium graminearum infect both heads and roots of cereal crops causing several economically important diseases such as head blight, seedling blight, crown rot and root rot. Trichothecene mycotoxins such as deoxynivalenol (DON), a well-known virulence factor, produced by F. graminearum (Fg) during disease development is also an important health concern. Although how F. graminearum infects above-ground tissues is relatively well studied, very little is known about molecular processes employed by the pathogen during below-ground infection. Also unknown is the role of DON during root infection. In the present study, we analyzed the transcriptome of F. graminearum during root infection of the model cereal Brachypodium distachyon. We also compared our Fg transcriptome data during root infection with those reported during wheat head infection. These analyses suggested that both shared and unique infection strategies employed by the pathogen during colonization of different host tissues. Several metabolite biosynthesis genes induced in F. graminearum during root infection could be linked to phytohormone production, implying that the pathogen likely interferes root specific defenses. In addition, to understand the role of DON in Fg root infection, we analyzed the transcriptome of the DON deficient Tri5 mutant. These analyses showed that the absence of DON had a significant effect on fungal transcriptional responses. Although DON was produced in infected roots, this mycotoxin did not act as a virulence factor during root infection. Our results reveal new mechanistic insights into the below-ground strategies employed by F. graminearum that may benefit the development of new genetic tools to combat this important cereal pathogen.

microbiology↗

bioRxiv2020

Natural gene drives offer potential pathogen control strategies in plants

O_LIGlobally, fungal pathogens cause enormous crop losses and current control practices are not always effective, economical or environmentally sustainable. Tools enabling genetic management of wild pathogen populations could potentially solve many problems associated with plant diseases. C_LIO_LIA natural gene drive from a heterologous species can be used in the globally important cereal pathogen, Fusarium graminearum, to remove pathogenic traits from contained populations of the fungus. The gene drive element became fixed in a freely crossing populations in only three generations. C_LIO_LIRepeat induce point mutation, a natural genome defence mechanism in fungi, may be useful to recall the gene drive following release, should a failsafe mechanism be required. C_LIO_LIWe propose that gene drive technology is a potential tool to control plant pathogens. C_LI

genetics↗

bioRxiv2019

Novel regulators of nitric oxide signaling triggered by host perception in a plant pathogen

The rhizosphere interaction between plant roots or pathogenic microbes is initiated by mutual exchange of signals. However, how soil pathogens sense host signals is largely unknown. Here, we studied early molecular events associated with host recognition in Fusarium graminearum, an economically important fungal pathogen that can infect both roots and heads of cereal crops. We found that host-sensing prior to physical contact with plant roots radically alters the transcriptome and triggers nitric oxide (NO) production in F. graminearum. We identified an ankyrin-repeat domain containing protein (FgANK1) required for host-mediated NO production and virulence in F. graminearum. In the absence of host plant, FgANK1 resides in the cytoplasm. In response to host signals, FgANK1 translocates to the nucleus and interacts with a zinc finger transcription factor (FgZC1), also required for NO production and virulence in F. graminearum. Our results reveal new mechanistic insights into host-recognition strategies employed by soil pathogens.

pathology↗