The Fusarium oxysporum species complex (FOSC) includes both plant and human pathogens that cause devastating plant vascular wilt diseases and threaten public health. Each F. oxysporum genome comprises core chromosomes (CCs) for housekeeping functions and accessory chromosomes (ACs) that contribute to host-specific adaptation. This study inspects global transcription factor profiles (TFomes) and their potential roles in coordinating CC and AC functions to accomplish host-specific interactions. Remarkably, we found a clear positive correlation between the sizes of TFomes and the proteomes of an organism. With the acquisition of ACs, the FOSC TFomes were larger than the other fungal genomes included in this study. Among a total of 48 classified TF families, 14 families involved in transcription/translation regulations and cell cycle controls were highly conserved. Among the 30 FOSC expanded families, Zn2-C6 and Znf_C2H2 were most significantly expanded to 671 and 167 genes per family including well-characterized homologs of Ftf1 (Zn2-C6) and PacC (Znf_C2H2) that are involved in host-specific interactions. Manual curation of characterized TFs increased the TFome repertoires by 3% including a disordered protein Ren1. RNA-Seq revealed a steady pattern of expression for conserved TF families and specific activation for AC TFs. Functional characterization of these TFs could enhance our understanding of transcriptional regulation involved in FOSC cross-kingdom interactions, disentangle species-specific adaptation, and identify targets to combat diverse diseases caused by this group of fungal pathogens.
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Analysis of five near-complete genome assemblies of the tomato pathogen Cladosporium fulvum uncovers additional accessory chromosomes and structural variations induced by transposable elements effecting the loss of avirulence genes
Fungal plant pathogens have dynamic genomes that allow them to rapidly adapt to adverse conditions and overcome host resistance. One way by which this dynamic genome plasticity is expressed is through effector gene loss, which enables plant pathogens to overcome recognition by cognate resistance genes in the host. However, the exact nature of these loses remains elusive in many fungi. This includes the tomato pathogen
Here, we obtained near-complete genome assemblies of four additional
Our results reveal new evolutionary aspects of the
- NSF-PAR ID:
- 10488032
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- BMC Biology
- Volume:
- 22
- Issue:
- 1
- ISSN:
- 1741-7007
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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ABSTRACT The World Health Organization recently published the first list of priority fungal pathogens highlighting multiple
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Xoo pathosystem, we aimed at identifying those that may act as Avr factor within AfricanXoo . We screened 86 rice accessions, and identified 12 that were resistant to two African strains while being susceptible to a well-studied Asian strain. In a gain of function approach based on the introduction of each of the ninetal genes of the avirulent African strain MAI1 into the virulent Asian strain PXO99A, four were found to trigger resistance on specific rice accessions. Loss-of-function mutational analysis further demonstrated theavr activity of two of them,talD andtalI, on the rice varieties IR64 and CT13432 respectively. Further analysis of TalI demonstrated the requirement of its activation domain for triggering resistance in CT13432. Resistance in 9 of the 12 rice accessions that were resistant against AfricanXoo specifically, including CT13432, could be suppressed or largely suppressed by trans-expression of the truncTALEtal2h , similarly to resistance conferred by theXa1 gene which recognizes TALEs generally independently of their activation domain.Conclusion We identified and characterized TalD and TalI as two African
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Summary Effective and durable disease resistance for bacterial blight (BB) of rice is a continuous challenge due to the evolution and adaptation of the pathogen,
Xanthomonas oryzae pv.oryzae (Xoo ), on cultivated rice varieties. Fundamental to this pathogens’ virulence is transcription activator‐like (TAL) effectors that activate transcription of host genes and contribute differently to pathogen virulence, fitness or both. Host plant resistance is predicted to be more durable if directed at strategic virulence factors that impact both pathogen virulence and fitness. We characterized Tal7b, a minor‐effect virulence factor that contributes incrementally to pathogen virulence in rice, is a fitness factor to the pathogen and is widely present in geographically diverse strains ofXoo . To identify sources of resistance to this conserved effector, we used a highly virulent strain carrying a plasmid borne copy of Tal7b to screen an indica multi‐parent advanced generation inter‐cross (MAGIC) population. Of 18 QTL revealed by genome‐wide association studies and interval mapping analysis, six were specific to Tal7b (qBB‐tal7b ). Overall, 150 predicted Tal7b gene targets overlapped with qBB‐tal7b QTL. Of these, 21 showed polymorphisms in the predicted effector binding element (EBE) site and 23 lost the EBE sequence altogether. Inoculation and bioinformatics studies suggest that the Tal7b target in one of the Tal7b‐specific QTL, qBB‐tal7b ‐8, is a disease susceptibility gene and that the resistance mechanism for this locus may be through loss of susceptibility. Our work demonstrates that minor‐effect virulence factors significantly contribute to disease and provide a potential new approach to identify effective disease resistance.
