Abstract
Pseudomonas syringae pv. glycinea PG4180 causes bacterial blight of soybean and produces the phytotoxin coronatine (COR) in a temperature-dependent manner. COR consists of a polyketide, coronafacic acid (CFA), and an amino acid derivative, coronamic acid, and is produced optimally at 18 degrees C whereas no detectable synthesis occurs at 28 degrees C. We investigated the impact of temperature on PG4180 during compatible and incompatible interactions with soybean and tobacco plants, respectively. After spray inoculation, PG4180 caused typical bacterial blight symptoms on soybean plants when the bacteria were grown at 18 degrees C prior to inoculation but not when derived from cultures grown at 28 degrees C. The disease outcome was quantified by determination of bacterial populations in planta. The temperature effect was not observed when PG4180 was artificially infiltrated into soybean leaves, indicating that the pre-inoculation temperature and phytotoxin synthesis were important for bacterial invasion via natural plant openings. In the incompatible interaction, PG4180 elicited the hypersensitive response (HR) on tobacco plants regardless of the bacterial pre-inoculation temperature. However, the HR was significantly delayed when tobacco plants were treated with cells of the CFA-overproducing derivative, PG4180.N9, which were derived from cultures grown at 18 degrees C, compared with parallels incubated at 28 degrees C. CFA biosynthesis by PG4180.N9 was optimal at 18 degrees C and negligible at 28 degrees C. The impact of CFA synthesis on the HR was studied with different growth media, mutants, and transconjugants of PG4180, indicating that the amount of synthesized CFA but not that of COR influenced the outcome of the HR. Feeding experiments with purified coronafacoyl compounds suggested that the observed delay of the HR was mediated by CFA, shedding further light on CFA's putative role as a molecular mimic of the plant signaling molecule, jasmonic acid.
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 6
Claim · model-written summary
PG4180 from 18 degree cultures caused soybean bacterial blight, whereas bacteria from 28 degree cultures did not.
- Taxon
- soybean
Glycine maxe0 - Treatment
- spray inoculatione0
- Interactor
- PG4180e0pathogen
- Outcome
- bacterial blight symptomse0
- Direction
- causede0
- Comparator
- cultures grown at 28 degrees Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After spray inoculation, PG4180 caused typical bacterial blight symptoms on soybean plants when the bacteria were grown at 18 degrees C prior to inoculation but not when derived from cultures grown at 28 degrees C.”
Claim · model-written summary
The culture temperature effect was absent after artificial infiltration into soybean leaves.
- Taxon
- soybeanGlycine maxe0
- Treatment
- artificially infiltratede0
- Interactor
- PG4180e0pathogen
- Outcome
- temperature effecte0
- Direction
- not observede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The temperature effect was not observed when PG4180 was artificially infiltrated into soybean leaves”
Claim · model-written summary
PG4180 elicited tobacco hypersensitive response regardless of pre-inoculation temperature.
- Taxon
- tobacco
Nicotiana tabacume0 - Interactor
- PG4180e0pathogen
- Outcome
- hypersensitive response (HR)e0
- Qualifier
- regardless of the bacterial pre-inoculation temperaturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PG4180 elicited the hypersensitive response (HR) on tobacco plants regardless of the bacterial pre-inoculation temperature”
Claim · model-written summary
The CFA-overproducing derivative grown at 18 degrees C significantly delayed tobacco hypersensitive response versus 28 degrees C.
- Taxon
- tobaccoNicotiana tabacume0
- Treatment
- cells of the CFA-overproducing derivative, PG4180.N9e0
- Interactor
- PG4180.N9e0pathogen
- Compound
- CFAe0
- Outcome
- HRe0
- Direction
- delayede0
- Comparator
- parallels incubated at 28 degrees Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the HR was significantly delayed when tobacco plants were treated with cells of the CFA-overproducing derivative, PG4180.N9, which were derived from cultures grown at 18 degrees C, compared with parallels incubated at 28 degrees C”
Claim · model-written summary
The amount of CFA, rather than COR, influenced tobacco hypersensitive response.
- Taxon
- tobaccoNicotiana tabacume1
- Compound
- CFAe0
- Outcome
- outcome of the HRe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the amount of synthesized CFA but not that of COR influenced the outcome of the HR”
e1“PG4180 elicited the hypersensitive response (HR) on tobacco plants regardless of the bacterial pre-inoculation temperature”
Claim · model-written summary
Feeding experiments suggested CFA mediated the delay in tobacco hypersensitive response.
- Taxon
- tobaccoNicotiana tabacume1
- Compound
- CFAe0
- Outcome
- delay of the HRe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Feeding experiments with purified coronafacoyl compounds suggested that the observed delay of the HR was mediated by CFA”
e1“PG4180 elicited the hypersensitive response (HR) on tobacco plants regardless of the bacterial pre-inoculation temperature”
The same questions in other papers
application · disease · Glycine max (soybean)Positive and negative results
45 papers in the same direction as this paper · 7 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- negative
50 papers more in this group
See all 54 papers →inoculation · disease · Glycine max (soybean)Positive and negative results
59 papers in the same direction as this paper · 67 in the opposite direction
- negative
- no effect
- negative
123 papers more in this group
See all 127 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.