Abstract
The mechanisms determining the host range of Xanthomonas are still undeciphered, despite much interest in their potential roles in the evolution and emergence of plant pathogenic bacteria. Xanthomonas citri pv. citri (Xci) is an interesting model of host specialization because of its pathogenic variants: pathotype A strains infect a wide range of Rutaceous species, whereas pathotype A*/A(W) strains have a host range restricted to Mexican lime (Citrus aurantifolia) and alemow (Citrus macrophylla). Based on a collection of 55 strains representative of Xci worldwide diversity assessed by amplified fragment length polymorphism (AFLP), we investigated the distribution of type III effectors (T3Es) in relation to host range. We examined the presence of 66 T3Es from xanthomonads in Xci and identified a repertoire of 28 effectors, 26 of which were shared by all Xci strains, whereas two (xopAG and xopC1) were present only in some A*/A(W) strains. We found that xopAG (=avrGf1) was present in all A(W) strains, but also in three A* strains genetically distant from A(W) , and that all xopAG-containing strains induced the hypersensitive response (HR) on grapefruit and sweet orange. The analysis of xopAD and xopAG suggested horizontal transfer between X. citri pv. bilvae, another citrus pathogen, and some Xci strains. A strains were genetically less diverse, induced identical phenotypic responses and possessed indistinguishable T3E repertoires. Conversely, A*/A(W) strains exhibited a wider genetic diversity in which clades correlated with geographical origin and T3E repertoire, but not with pathogenicity, according to T3E deletion experiments. Our data outline the importance of taking into account the heterogeneity of Xci A*/A(W) strains when analysing the mechanisms of host specialization.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 7
Claim · model-written summary
Xci strains carried 28 effectors, of which 26 were shared by all strains.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“identified a repertoire of 28 effectors, 26 of which were shared by all Xci strains”
e1“another citrus pathogen”
Claim · model-written summary
xopAG and xopC1 were restricted to some A*/A(W) strains.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two (xopAG and xopC1) were present only in some A*/A(W) strains”
e1“another citrus pathogen”
Claim · model-written summary
xopAG occurred in all A(W) strains and three genetically distant A* strains.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“xopAG (=avrGf1) was present in all A(W) strains, but also in three A* strains genetically distant from A(W)”
e1“another citrus pathogen”
Claim · model-written summary
All xopAG-containing strains induced hypersensitive response on grapefruit and sweet orange.
- Taxon
- grapefruit and sweet orange
Citrus sinensis_Pompelino_Grapefruit_002.jpg?width=60)
Citrus ×paradisie0 - Interactor
- Xanthomonas citri pv. citriXanthomonas citri pv. citrie1pathogen
- Gene
- xopAGe0
- Outcome
- hypersensitive response (HR)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Pompelino_Grapefruit_002.jpg?width=500)
Verbatim
e0“all xopAG-containing strains induced the hypersensitive response (HR) on grapefruit and sweet orange”
e1“Xanthomonas citri pv. citri (Xci)”
Claim · model-written summary
xopAD and xopAG analysis suggested horizontal transfer between X. citri pv. bilvae and some Xci strains.
- Interactor
- X. citri pv. bilvaeXanthomonas citri pv. bilvaee0pathogen
- Gene
- xopAD and xopAGe0
- Outcome
- horizontal transfere0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“analysis of xopAD and xopAG suggested horizontal transfer between X. citri pv. bilvae, another citrus pathogen, and some Xci strains”
Claim · model-written summary
A strains were genetically less diverse and had identical phenotypic responses and indistinguishable effector repertoires.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A strains were genetically less diverse, induced identical phenotypic responses and possessed indistinguishable T3E repertoires”
e1“another citrus pathogen”
Claim · model-written summary
A*/A(W) clades correlated with geographic origin and effector repertoire, but not pathogenicity.
- Interactor
- A*/A(W) strainse0pathogen
- Outcome
- clades correlated with geographical origin and T3E repertoiree0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A*/A(W) strains exhibited a wider genetic diversity in which clades correlated with geographical origin and T3E repertoire, but not with pathogenicity”
e1“another citrus pathogen”