Biology subjects

Tan, Y. P.

Publications and source records attributed to Tan, Y. P..

3 recordsLinked to original sources

bioRxiv2026

Genetic characterisation and aggressiveness of the Fusarium oxysporum Species Complex in tomato plants and irrigation water from Australian processing fields

Fusarium oxysporum Species Complex (FOSC) includes important soilborne pathogens of a range of crops worldwide. In Victoria (VIC) and New South Wales (NSW), Australia, FOSC has been identified as the cause of stunting and poor growth in processing tomato fields, resulting in significant yield losses. A total of 40 FOSC isolates were obtained from symptomatic tomato plants, irrigation water samples and culture collections, which were confirmed to be FOSC by multi-gene phylogenetic analyses based on four genomic loci: beta tubulin, calmodulin, the second largest subunit of nuclear RNA polymerase II, and translation elongation factor one-alpha. There was a high level of genetic diversity among isolates, with multiple phylogenetic lineages detected. Glasshouse bioassays demonstrated that all isolates were pathogenic to processing tomato, resulting in significant reductions in plant growth, with above ground height reduced by 11 to 26% and root dry weight by 44 to 83% compared with the control (p < 0.05). Although aggressiveness varied among isolates, growth reduction occurred irrespective of their phylogenetic placement. Moreover, the shared genetic background of isolates from irrigation water and plant samples highlights the role of irrigation water as a potential source of inoculum in Fusarium epidemics, underscoring its significance for disease management in Australian processing tomato systems.

plant biology↗

bioRxiv2020

NLRP3 inflammasome contributes to host defense against Talaromyces marneffei infection

Talaromyces marneffei is an important thermally dimorphic pathogen causing disseminated mycoses in immunocompromised individuals in southeast Asia. Previous study has suggested that NLRP3 inflammasome plays a critical role in antifungal immunity. However, the mechanism underlying the role of NLRP3 inflammasome activation in host defense against T. marneffei remains unclear. We show that T. marneffei yeasts but not conidia induce potent IL-1{beta} response, which is differentially regulated in discrete immune cell types. Dectin-1/Syk signaling pathway mediates pro-IL-1{beta} production, and NLRP3 inflammasome is activated to trigger the processing of pro-IL-1{beta} into IL-1{beta}. The activated NLRP3 inflammasome partially promotes Th1 and Th17 immune responses against T. marneffei yeasts. In vivo, mice with NLRP3 or caspase-1 deficiency exhibit higher mortality rate and fungal load compared to wild-type mice. Herein, our study provides the first evidence that NLRP3 inflammasome contributes to host defense against T. marneffei infection, which may have implications for future antifungal therapeutic designs.

microbiology↗

bioRxiv2019

Genome mining of the citrus pathogen Elsinoë fawcettii; prediction and prioritisation of candidate effectors, cell wall degrading enzymes and secondary metabolite gene clusters

AbstractElsinoe fawcettii, a necrotrophic fungal pathogen, causes citrus scab on numerous citrus varieties around the world. Known pathotypes of E. fawcettii are based on host range; additionally, cryptic pathotypes have been reported and more novel pathotypes are thought to exist. E. fawcettii produces elsinochrome, a non-host selective toxin which contributes to virulence. However, the mechanisms involved in potential pathogen-host interactions occurring prior to the production of elsinochrome are unknown, yet the host-specificity observed among pathotypes suggests a reliance upon such mechanisms. In this study we have generated a whole genome sequencing project for E. fawcettii, producing an annotated draft assembly 26.01 Mb in size, with 10,080 predicted gene models and low (0.37%) coverage of transposable elements. The assembly showed evidence of AT-rich regions, potentially indicating genomic regions with increased plasticity. Using a variety of computational tools, we mined the E. fawcettii genome for potential virulence genes as candidates for future investigation. A total of 1,280 secreted proteins and 203 candidate effectors were predicted and compared to those of other necrotrophic (Botrytis cinerea, Parastagonospora nodorum, Pyrenophora tritici-repentis, Sclerotinia sclerotiorum and Zymoseptoria tritici), hemibiotrophic (Leptosphaeria maculans, Magnaporthe oryzae, Rhynchosporium commune and Verticillium dahliae) and biotrophic (Ustilago maydis) plant pathogens. Genomic and proteomic features of known fungal effectors were analysed and used to guide the prioritisation of 77 candidate effectors of E. fawcettii. Additionally, 378 carbohydrate-active enzymes were predicted and analysed for likely secretion and sequence similarity with known virulence genes. Furthermore, secondary metabolite prediction indicated nine additional genes potentially involved in the elsinochrome biosynthesis gene cluster than previously described. A further 21 secondary metabolite clusters were predicted, some with similarity to known toxin producing gene clusters. The candidate virulence genes predicted in this study provide a comprehensive resource for future experimental investigation into the pathogenesis of E. fawcettii.

genomics↗