- 期刊
臺灣草莓灰黴病菌對賽普護汰寧不同感受性菌株之分子特性
Molecular Characterization of Botrytis cinerea Isolates from Strawberry with Different Sensitivities to Cyprodinil+fludioxonil in Taiwan
摘要
草莓灰黴病菌（Botrytis cinerea）是易產生抗藥性的植物病原真菌，常以殺菌劑賽普護汰寧進行防治。本研究以2018及2019年分離自臺灣各地12株對賽普護汰寧不同感受性（EC_(50)=0.023～2.986 μg a.i./mL）的草莓灰黴病菌為供試菌株，分析其與抗藥性相關之蛋白質序列及基因表現量，以探討這些變異同抗藥性的關係。Bos1蛋白質序列分析結果指出，供試菌株的Bos1蛋白質序列共有6個點突變，分別為F127S、I365N/S、N373S、Q369P、V1136I及D757N；其中F127S及I365N僅出現於低感藥菌株（D1、D11及G5）。Mrr1蛋白質序列分析結果則顯示，供試菌株的mrr1蛋白質序列總計有42個點突變，其中V287S、M432T、L497deletion、F568S、R634K及N666G等均出現於較低感藥菌株（D11及G5），其他點突變則遍布不同感藥程度菌株。根據上述結果推測，此兩種蛋白質（Bos1及mrr1）所指的點突變可能與灰黴病菌對賽普護汰寧抗藥性有關。至於Bchog1基因表現量，則高感藥菌株表現量較高並隨菌株感藥程度降低而減少；當加以賽普護汰寧1 μg a.i./mL處理後，其基因表現量僅能少量提升，甚或略減。
並列摘要
Botrytis cinerea is a filamentous phytopathogen with a high risk of developing resistance to fungicides. Cyprodinil+fludioxonil (a premixture) is the most frequently used fungicide against B. cinerea in Taiwan. In this study, molecular characteristics of 12 isolates of B. cinerea obtained from strawberry fruit with different sensitivities to this fungicide were investigated. Their fungicide sensitivities were specifically determined according to median effective concentration values (EC_(50)), which ranged from 0.023 to 2.986 μg a.i./mL. In comparing the Bos1 protein sequence of tested isolates with that of wild type isolate B05.10 (XP_024546375), 6 amino acid alterations were observed, including in F127S, I365N/S, N373S, Q369P, V1136I and D757N. Among these, alterations in F127S and I365N only occurred in less sensitive isolates (D1, D11 and G5). In comparing the mrr1 protein sequence of tested isolates with that of wild type isolate N11_K_W08b (AFS33265), we identified a total of 42 amino acid alterations. Among these, alterations in V287S, M432T, L497 deletion, F568S, R634K and N666G only occurred in less sensitive isolates (D11 and G5). We posit that some of the point mutations in Bos1 and mrr1 among D11 and G5 isolates may be correlated with the reduced sensitivity to the fungicide that these isolates possess. In addition, more sensitive isolates consistently exhibited greater Bchog1 expression than did isolates with lower sensitivities. Finally, when further treated with the fungicide at 1 μg a.i./mL, most isolates showed slightly higher Bchog1 expression levels. Findings from this study should enhance our understanding of the resistance mechanism of B. cinerea to cyprodinil+fludioxonil.