Proteomic analysis on zoxamide-induced sensitivity changes in Phytophthora cactorum.
Zoxamide is an important fungicide for oomycete disease management. In this study, we established the baseline sensitivity of Phytophthora cactorum to zoxamide and assessed the risk of developing resistance to zoxamide using ultraviolet irradiation and fungicide taming methods. All 73 studied isolates were sensitive to zoxamide, with effective concentrations for 50% inhibition of mycelial growth ranging from 0.04 to 0.29 mg/L and mean of 0.15 mg/L. Stable zoxamide-resistant mutants of P. cactorum were not obtained from four arbitrarily selected isolates by either treating mycelial cultures with ultraviolet irradiation or adapting mycelial cultures to the addition of increasing zoxamide concentrations. However, the sensitivity of the isolates to zoxamide could be easily reduced by successive zoxamide treatments. In addition to displaying decreased sensitivity to zoxamide, these isolates also showed decreased sensitivity to the fungicides flumorph and cymoxanil. Proteomic analysis indicated that some proteins involved in antioxidant detoxification, ATP-dependent multidrug resistance, and anti-apoptosis activity, are likely responsible for the induced decrease in the sensitivity of P. cactorum to zoxamide compared to controls. Further semi-quantitative PCR analysis demonstrated that the gene expression profiles of most of above proteins were consistent with the proteomic analysis. Based on the above results, P. cactorum shows low resistance risk to zoxamide; however, the fungicidal effect of zoxamide might be decreased due to induced resistance when this fungicide is continuously applied.
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Xinyue
X
Mei
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Min
M
Yang
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Bingbing
B
Jiang
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Xupo
X
Ding
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Weiping
W
Deng
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
Yumei
Y
Dong
College of Forestry, Beijing Forestry University, No. 35, Tsinghua Eastern Road, Haidian District, Beijing 100083, China.
Lei
L
Chen
Department of Plant Pathology, College of Agriculture and Biotechnology, China Agricultural University, Beijing 100091, China.
Xili
X
Liu
Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, Yunnan 650201, China. Electronic address: shushengzhu79@126.com.
Shusheng
S
Zhu
D000081:Acetamides; D000577:Amides; D026141:Drug Resistance, Multiple, Fungal / Q000528:radiation effects; D009025:Morpholines; D010838:Phytophthora / Q000502:physiology*; D040901:Proteomics; D014466:Ultraviolet Rays
D000081:Acetamides; D000577:Amides; D009025:Morpholines; C528737:flumorph; C451427:zoxamide; C025644:2-cyano-N-((ethylamino)carbonyl)-2-(methoxyimino)acetamide
Detoxification metabolism; Induced resistance; Multidrug resistance