Abstract
ABSTRACT We reported previously that physiological leaf spot (PLS) formation in winter and spring barley is dependent on genotype-related oxidative stress under field conditions. In the present study, we searched for factors inducing PLS symptoms in the greenhouse similar to those observed in the field and investigated its relationship to reactive oxygen species (ROS) metabolism. We found that in the greenhouse, oxidative stress induced spring barley cv. Extract, which is sensitive to PLS, to express symptoms similar to those observed in the field. Leaves severely affected by PLS showed significantly lower activities of key enzymes in the Halliwell-Asada cycle such as ascorbate peroxidase, glutathione reductase, dehy-droascorbate reductase, and monodehydroascorbate reductase. The sensitive cultivar also showed lower levels of total superoxide dismutase (SOD) and Cu/Zn-SOD activity but a higher level of chloroplast-specific Fe-SOD activity than that of the insensitive cultivar. Thus, an unbalanced ROS metabolism in chloroplasts may trigger PLS incidence in sensitive cultivars, which is in agreement with the fact that light is essential for the induction of PLS expression under both field and greenhouse conditions. Accordingly, under greenhouse conditions, continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett. Light with a high proportion of energy in the blue wavelength spectrum (350 to 560 nm) was significantly more PLS inductive than light with a pronounced red (photosynthetically active radiation) spectrum (580 to 650 nm). Exposure to ozone did not produce PLS-like symptoms. Furthermore, similar to earlier observations in the field, PLS symptom expression was closely correlated with the accumulation of superoxide (O(2) (-)) detected by both biochemical and histochemical assays. Taken together, these data suggest that PLS in barley is genotype-dependent but its expression appears to be induced by certain environmental stress factors, among which photosyn-thetically active radiation plays a major role.
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Claims 11
Claim · model-written summary
Oxidative stress induced field-like leaf spot in sensitive spring barley Extract.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0 - Material
- Extracte0
- Treatment
- oxidative stresse0
- Outcome
- symptoms similar to those observed in the fielde0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“oxidative stress induced spring barley cv. Extract, which is sensitive to PLS, to express symptoms similar to those observed in the field”
Claim · model-written summary
Severely affected leaves had significantly lower activities of four Halliwell-Asada enzymes.
- Taxon
- BarleyHordeum vulgaret0
- Organ / stage
- Leavese0
- Gene
- ascorbate peroxidase, glutathione reductase, dehy-droascorbate reductase, and monodehydroascorbate reductasee0
- Outcome
- activities of key enzymes in the Halliwell-Asada cyclee0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaves severely affected by PLS showed significantly lower activities of key enzymes in the Halliwell-Asada cycle such as ascorbate peroxidase, glutathione reductase, dehy-droascorbate reductase, and monodehydroascorbate reductase”
t0“Barley”
Claim · model-written summary
Sensitive cultivar had lower total and Cu/Zn-SOD activity than insensitive cultivar.
- Taxon
- BarleyHordeum vulgaret0
- Material
- sensitive cultivare0
- Outcome
- total superoxide dismutase (SOD) and Cu/Zn-SOD activitye0
- Direction
- lowere0
- Comparator
- insensitive cultivare0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The sensitive cultivar also showed lower levels of total superoxide dismutase (SOD) and Cu/Zn-SOD activity but a higher level of chloroplast-specific Fe-SOD activity than that of the insensitive cultivar”
t0“Barley”
Claim · model-written summary
Sensitive cultivar had higher chloroplast Fe-SOD activity than insensitive cultivar.
- Taxon
- BarleyHordeum vulgaret0
- Outcome
- chloroplast-specific Fe-SOD activitye0
- Direction
- highere0
- Comparator
- insensitive cultivare0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a higher level of chloroplast-specific Fe-SOD activity than that of the insensitive cultivar”
t0“Barley”
Claim · model-written summary
Continuous light stress induced field-like leaf spot in Extract.
- Taxon
- BarleyHordeum vulgaret0
- Material
- Extracte0
- Treatment
- continuous light stress (7 days)e0
- Outcome
- PLS similar to that of field conditionse0
- Direction
- inducede0
- Comparator
- light shock treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett”
t0“Barley”
Claim · model-written summary
Light shock did not induce field-like leaf spot.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- light shock treatmentse0
- Outcome
- PLS similar to that of field conditionse0
- Comparator
- continuous light stress (7 days)e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett”
t0“Barley”
Claim · model-written summary
Resistant Scarlett did not develop field-like leaf spot under continuous light.
- Taxon
- BarleyHordeum vulgaret0
- Material
- Scarlette0
- Treatment
- continuous light stress (7 days)e0
- Outcome
- PLS similar to that of field conditionse0
- Comparator
- Extracte0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“continuous light stress (7 days), but not light shock treatments, induced PLS similar to that of field conditions in sensitive cv. Extract, but not in resistant cv. Scarlett”
t0“Barley”
Claim · model-written summary
Blue-rich light induced significantly more leaf spot than red-rich light.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- Light with a high proportion of energy in the blue wavelength spectrum (350 to 560 nm)e0
- Outcome
- PLSe0
- Direction
- more PLS inductivee0
- Comparator
- light with a pronounced red (photosynthetically active radiation) spectrum (580 to 650 nm)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Light with a high proportion of energy in the blue wavelength spectrum (350 to 560 nm) was significantly more PLS inductive than light with a pronounced red (photosynthetically active radiation) spectrum (580 to 650 nm)”
t0“Barley”
Claim · model-written summary
Ozone did not produce leaf spot-like symptoms.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- Exposure to ozonee0
- Outcome
- PLS-like symptomse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exposure to ozone did not produce PLS-like symptoms”
t0“Barley”
Claim · model-written summary
Leaf spot expression correlated with superoxide accumulation.
- Taxon
- BarleyHordeum vulgaret0
- Compound
- superoxide (O(2) (-))e0
- Outcome
- PLS symptom expressione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PLS symptom expression was closely correlated with the accumulation of superoxide (O(2) (-))”
t0“Barley”
Claim · model-written summary
Authors suggest unbalanced chloroplast ROS metabolism may trigger leaf spot.
- Taxon
- BarleyHordeum vulgaret0
- Outcome
- PLS incidencee0
- Qualifier
- unbalanced ROS metabolism in chloroplastse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an unbalanced ROS metabolism in chloroplasts may trigger PLS incidence in sensitive cultivars”
t0“Barley”
The same questions in other papers
ozone · disease · Hordeum vulgare (barley)Positive and negative results
1 in the opposite direction
- positive
light · disease · Hordeum vulgare (barley)Positive and negative results
5 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
4 papers more in this group
See all 8 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.