ORCID Profile
0000-0003-2808-8369
Current Organisation
Australian National University
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Publisher: eLife Sciences Publications, Ltd
Date: 18-07-2023
DOI: 10.7554/ELIFE.89280
Abstract: Plant pathogens secrete proteins, known as effectors, that function in the apoplast or inside plant cells to promote virulence. Effector detection by cell-surface or cytosolic receptors results in the activation of defence pathways and plant immunity. Despite their importance, our general understanding of fungal effector function and detection by immunity receptors remains poor. One complication often associated with effectors is their high sequence ersity and lack of identifiable sequence motifs precluding prediction of structure or function. In recent years, several studies have demonstrated that fungal effectors can be grouped into structural classes, despite significant sequence variation and existence across taxonomic groups. Using protein x-ray crystallography, we identify a new structural class of effectors hidden within the secreted in xylem (SIX) effectors from Fusarium oxysporum f. sp. lycopersici (Fol). The recognised effectors Avr1 (SIX4) and Avr3 (SIX1) represent the founding members of the Fol dual-domain (FOLD) effector class, with members containing two distinct domains. Using AlphaFold2, we predicted the full SIX effector repertoire of Fol and show that SIX6 and SIX13 are also FOLD effectors, which we validated experimentally for SIX6. Based on structural prediction and comparisons, we show that FOLD effectors are present within three isions of fungi and are expanded in pathogens and symbionts. Further structural comparisons demonstrate that Fol secretes a limited number of structurally related effectors during infection of tomato. This analysis also revealed a structural relationship between transcriptionally co-regulated effector pairs. We make use of the Avr1 structure to understand its recognition by the I receptor, which lead to disease resistance in tomato. This study represents an important advance in our understanding of Fol-tomato, and by extension plant-fungal interactions, which will assist the development of novel control and engineering strategies to combat plant pathogens.
Publisher: Wiley
Date: 24-06-2021
DOI: 10.1111/NPH.17516
Abstract: Plant pathogens cause disease through secreted effector proteins, which act to promote infection. Typically, the sequences of effectors provide little functional information and further targeted experimentation is required. Here, we utilized a structure/function approach to study SnTox3, an effector from the necrotrophic fungal pathogen Parastagonospora nodorum , which causes cell death in wheat‐lines carrying the sensitivity gene Snn3 . We developed a workflow for the production of SnTox3 in a heterologous host that enabled crystal structure determination and functional studies. We show this approach can be successfully applied to study effectors from other pathogenic fungi. The β‐barrel fold of SnTox3 is a novel fold among fungal effectors. Structure‐guided mutagenesis enabled the identification of residues required for Snn3 recognition. SnTox3 is a pre‐pro‐protein, and the pro‐domain of SnTox3 can be cleaved in vitro by the protease Kex2. Complementing this, an in silico study uncovered the prevalence of a conserved motif (LxxR) in an expanded set of putative pro‐domain‐containing fungal effectors, some of which can be cleaved by Kex2 in vitro . Our in vitro and in silico study suggests that Kex2‐processed pro‐domain (designated here as K2PP) effectors are common in fungi and this may have broad implications for the approaches used to study their functions.
Publisher: eLife Sciences Publications, Ltd
Date: 18-07-2023
Abstract: Plant pathogens secrete proteins, known as effectors, that function in the apoplast or inside plant cells to promote virulence. Effector detection by cell-surface or cytosolic receptors results in the activation of defence pathways and plant immunity. Despite their importance, our general understanding of fungal effector function and detection by immunity receptors remains poor. One complication often associated with effectors is their high sequence ersity and lack of identifiable sequence motifs precluding prediction of structure or function. In recent years, several studies have demonstrated that fungal effectors can be grouped into structural classes, despite significant sequence variation and existence across taxonomic groups. Using protein x-ray crystallography, we identify a new structural class of effectors hidden within the secreted in xylem (SIX) effectors from Fusarium oxysporum f. sp. lycopersici (Fol). The recognised effectors Avr1 (SIX4) and Avr3 (SIX1) represent the founding members of the Fol dual-domain (FOLD) effector class, with members containing two distinct domains. Using AlphaFold2, we predicted the full SIX effector repertoire of Fol and show that SIX6 and SIX13 are also FOLD effectors, which we validated experimentally for SIX6. Based on structural prediction and comparisons, we show that FOLD effectors are present within three isions of fungi and are expanded in pathogens and symbionts. Further structural comparisons demonstrate that Fol secretes a limited number of structurally related effectors during infection of tomato. This analysis also revealed a structural relationship between transcriptionally co-regulated effector pairs. We make use of the Avr1 structure to understand its recognition by the I receptor, which lead to disease resistance in tomato. This study represents an important advance in our understanding of Fol-tomato, and by extension plant-fungal interactions, which will assist the development of novel control and engineering strategies to combat plant pathogens.
Publisher: Cold Spring Harbor Laboratory
Date: 15-12-2021
DOI: 10.1101/2021.12.14.472499
Abstract: Plant pathogens secrete proteins, known as effectors, that function in the apoplast or inside plant cells to promote virulence. Effector detection by cell-surface or cytosolic receptors results in the activation of defence pathways and plant immunity. Despite their importance, our general understanding of fungal effector function and detection by immunity receptors remains poor. One complication often associated with effectors is their high sequence ersity and lack of identifiable sequence motifs precluding prediction of structure or function. In recent years, several studies have demonstrated that fungal effectors can be grouped into structural classes, despite significant sequence variation and existence across taxonomic groups. Using protein x-ray crystallography, we identify a new structural class of effectors hidden within the secreted in xylem (SIX) effectors from Fusarium oxysporum f. sp. lycopersici ( Fol ). The recognised effectors Avr1 (SIX4) and Avr3 (SIX1) represent the founding members of the Fol d ual-domain (FOLD) effector class, with members containing two distinct domains. Using AlphaFold2, we predicted the full SIX effector repertoire of Fol and show that SIX6 and SIX13 are also FOLD effectors, which we validated experimentally for SIX6. Based on structural prediction and comparisons, we show that FOLD effectors are present within three isions of fungi and are expanded in pathogens and symbionts. Further structural comparisons demonstrate that Fol secretes a limited number of structurally related effectors during infection of tomato. This analysis also revealed a structural relationship between transcriptionally co-regulated effector pairs. We make use of the Avr1 structure to understand its recognition by the I receptor, which lead to disease resistance in tomato. This study represents an important advance in our understanding of Fol -tomato, and by extension plant-fungal interactions, which will assist the development of novel control and engineering strategies to combat plant pathogens.
Location: Bangladesh
No related grants have been discovered for Sharmin Rima.