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The role of antioxidant enzymes in adaptive responses to sheath blight infestation under different fertilization rates and hill densities.

Wu W, Wan X, Shah F, Fahad S, Huang J - ScientificWorldJournal (2014)

Bottom Line: No rice cultivar has been found to be completely resistant to this fungus.Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity.Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons.

View Article: PubMed Central - PubMed

Affiliation: College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China ; National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.

ABSTRACT
Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and malondialdehyde content (MDA) responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method) were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development.

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Related in: MedlinePlus

Effect of fertilization rates on antioxidant enzyme activities and MDA content 3 and 7 days after inoculation (DAI) in double-season rice. Vertical bars indicate standard error. ∗ indicates significant difference between treatments according to LSD (0.05).
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fig3: Effect of fertilization rates on antioxidant enzyme activities and MDA content 3 and 7 days after inoculation (DAI) in double-season rice. Vertical bars indicate standard error. ∗ indicates significant difference between treatments according to LSD (0.05).

Mentions: POD and MDA increased with time after inoculation, but CAT and SOD did not show a similar trend (Figures (2)–(4)). POD, SOD, and MDA were significantly increased for the toothpick method, compared with CK (no pathogen inoculation), followed by the agar block method at 7 days after inoculation rather than at 3 days after inoculation (Figure 2). However, CAT was significantly lower for the agar block and toothpick methods than for CK at 7 days after inoculation. N application or supplemental silicon significantly increased POD, CAT, and MDA at 3 and 7 days after inoculation. However, this was not the case for SOD (Figure 3). Increased hill density significantly increased POD, SOD, and MDA at 7 days after inoculation (Figure 4). Correlation analysis showed that lesion length had positive and significant relationships with POD, MDA, and SOD and had negative relationships with CAT at 7 days after inoculation during both seasons (Table 1). However, there are no significant correlations between lesion length and any antioxidant enzyme activities and MDA content at 3 days after inoculation.


The role of antioxidant enzymes in adaptive responses to sheath blight infestation under different fertilization rates and hill densities.

Wu W, Wan X, Shah F, Fahad S, Huang J - ScientificWorldJournal (2014)

Effect of fertilization rates on antioxidant enzyme activities and MDA content 3 and 7 days after inoculation (DAI) in double-season rice. Vertical bars indicate standard error. ∗ indicates significant difference between treatments according to LSD (0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4127202&req=5

fig3: Effect of fertilization rates on antioxidant enzyme activities and MDA content 3 and 7 days after inoculation (DAI) in double-season rice. Vertical bars indicate standard error. ∗ indicates significant difference between treatments according to LSD (0.05).
Mentions: POD and MDA increased with time after inoculation, but CAT and SOD did not show a similar trend (Figures (2)–(4)). POD, SOD, and MDA were significantly increased for the toothpick method, compared with CK (no pathogen inoculation), followed by the agar block method at 7 days after inoculation rather than at 3 days after inoculation (Figure 2). However, CAT was significantly lower for the agar block and toothpick methods than for CK at 7 days after inoculation. N application or supplemental silicon significantly increased POD, CAT, and MDA at 3 and 7 days after inoculation. However, this was not the case for SOD (Figure 3). Increased hill density significantly increased POD, SOD, and MDA at 7 days after inoculation (Figure 4). Correlation analysis showed that lesion length had positive and significant relationships with POD, MDA, and SOD and had negative relationships with CAT at 7 days after inoculation during both seasons (Table 1). However, there are no significant correlations between lesion length and any antioxidant enzyme activities and MDA content at 3 days after inoculation.

Bottom Line: No rice cultivar has been found to be completely resistant to this fungus.Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity.Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons.

View Article: PubMed Central - PubMed

Affiliation: College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China ; National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.

ABSTRACT
Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and malondialdehyde content (MDA) responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method) were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development.

Show MeSH
Related in: MedlinePlus