Abstract
Xanthomonas translucens, the causal agent of bacterial leaf streak disease (BLS) in cereals, is a re-emerging pathogen that is becoming increasingly destructive across the world. While BLS has caused yield losses in the past, there is anecdotal evidence that newer isolates may be more virulent. We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates, and we hypothesize that genetic changes between recent and older isolates contribute to the differences in isolate aggressiveness. To test this, we phenotyped and genetically characterized two X. translucens isolates collected from Colorado in 2018, which we designated CO236 (from barley) and CO237 (from wheat). Using pathovar-specific phenotyping and PCR primers, we determined that CO236 belongs to pathovar translucens (Xtt) and CO237 belongs to pathovar undulosa (Xtu). We sequenced the full genomes of the isolates using Oxford Nanopore long-read sequencing, and compared their whole genomes against published X. translucens genomes. This analysis confirmed our pathovar designations for Xtt CO236 and Xtu CO237, and showed that, at the whole-genome level, there were no obvious genomic structural changes between Xtt CO236 and Xtu CO237 and other respective published pathovar genomes. Focusing on pathovar undulosa (Xtu CO237), we then compared putative type III effectors among all available Xtu isolate genomes and found that they were highly conserved. However, there were striking differences in the presence and sequence of various transcription activator-like effectors between Xtu CO237 and published undulosa genomes, which correlate with isolate virulence. Here, we explore the potential implications of the differences in these virulence factors, and provide possible explanations for the increased virulence of recently emerged isolates.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 8
Claim · model-written summary
Two X. translucens isolates collected in Colorado in 2018 are more aggressive on current wheat and barley varieties than older isolates.
- Taxon
- wheat and barley
.jpg?width=60)
Hordeum vulgare
Triticum aestivume0 - Treatment
- two X. translucens isolates collected from two sites in Colorado, USAe0
- Interactor
- X. translucens
Xanthomonas translucense0pathogen - Outcome
- aggressivee0
- Direction
- more aggressivee0
- Comparator
- older isolatese0
- Setting
- two sites in Colorado, USAe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“A recently collected Xanthomonas translucens isolate encodes TAL effectors distinct from older, less virulent isolates”
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
Claim · model-written summary
Isolate CO236 from barley belongs to pathovar translucens (Xtt).
- Taxon
- barleyHordeum vulgaree2
- Material
- CO236e1
- Outcome
- belongs to pathovare1
- Value
- translucens (Xtt)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A recently collected Xanthomonas translucens isolate encodes TAL effectors distinct from older, less virulent isolates”
e1“we determined that CO236 belongs to pathovar translucens (Xtt) and CO237 belongs to pathovar undulosa (Xtu)”
e2“which we designated CO236 (from barley) and CO237 (from wheat)”
Claim · model-written summary
Isolate CO237 from wheat belongs to pathovar undulosa (Xtu).
- Taxon
- wheatTriticum aestivume2
- Material
- CO237e1
- Outcome
- belongs to pathovare1
- Value
- undulosa (Xtu)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“A recently collected Xanthomonas translucens isolate encodes TAL effectors distinct from older, less virulent isolates”
e1“we determined that CO236 belongs to pathovar translucens (Xtt) and CO237 belongs to pathovar undulosa (Xtu)”
e2“which we designated CO236 (from barley) and CO237 (from wheat)”
Claim · model-written summary
At whole-genome level, there were no obvious genomic structural changes between Xtt CO236 and Xtu CO237 and other published pathovar genomes.
- Taxon
- wheat and barleyHordeum vulgareTriticum aestivume0
- Outcome
- genomic structural changese3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
e3“there were no obvious genomic structural changes between Xtt CO236 and Xtu CO237 and other respective published pathovar genomes”
Claim · model-written summary
Putative type III effectors were highly conserved among all available Xtu isolate genomes.
- Taxon
- wheat and barleyHordeum vulgareTriticum aestivume0
- Outcome
- putative type III effectorse4
- Qualifier
- highly conservede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
e4“putative type III effectors among all available Xtu isolate genomes and found that they were highly conserved”
Claim · model-written summary
Striking differences exist in the presence and sequence of TAL effectors between Xtu CO237 and published undulosa genomes.
- Taxon
- wheat and barleyHordeum vulgareTriticum aestivume0
- Interactor
- Xtu CO237e5pathogen
- Outcome
- presence and sequence of various transcription activator-like effectorse5
- Qualifier
- striking differencese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
e5“there were striking differences in the presence and sequence of various transcription activator-like effectors between Xtu CO237 and published undulosa genomes”
Claim · model-written summary
The TAL effector differences correlate with isolate virulence.
- Taxon
- wheat and barleyHordeum vulgareTriticum aestivume0
- Treatment
- transcription activator-like effectorse5
- Outcome
- isolate virulencee6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
e5“there were striking differences in the presence and sequence of various transcription activator-like effectors between Xtu CO237 and published undulosa genomes”
e6“which correlate with isolate virulence”
Claim · model-written summary
The differences in virulence factors may explain the increased virulence of recently emerged isolates.
- Taxon
- wheat and barleyHordeum vulgareTriticum aestivume0
- Outcome
- increased virulencee7
- Qualifier
- differences in these virulence factorse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We observed that two X. translucens isolates collected from two sites in Colorado, USA, are more aggressive on current wheat and barley varieties compared to older isolates”
e7“the potential implications of the differences in these virulence factors, and provide possible explanations for the increased virulence of recently emerged isolates”