Upregulation of miR395 which Targets ATP Sulfurylase and Sulfate Transporter Facilitates Sulfur Enhanced Defence after Hibiscus chlorotic ringspot virus Infection

郜瑞敏(R. Gao) ； 陳嘉欣(D. J. X. Tan) ； 王錫民(S. M. Wong)

《植物病理學會刊》 22卷2期 (2013/06) Pp. 133-143

https://doi.org/10.6649/PPB.201306_22(2).0005

摘要

研究顯示木槿黃化輪斑病毒（Hibiscus chlorotic ringspot virus，HCRSV）的外鞘蛋白（coat protein，CP）與亞硫酸氧化酶（sulfite oxidase，SO）作用會啟動硫促防禦機制（sulfur enhanced defence，SED）。調控三磷酸腺苷硫酸化酶基因（ATPsulfurylase，ATPS）與硫酸根轉運蛋白基因（sulfate transporter，SULTR）的MicroRNA395（miR395）是目前唯一被報導參與硫代謝反應機轉的一個miRNA。ATPS和SULTR分別是在SED反應途逕中參與產生谷胱甘肽和轉運硫酸盐的酵素。本研究使用洋麻（kenaf，Hibiscuscannabinus L.）為HCRSV的寄主植物進行實驗。吾人研究miR395與其目標基因ATPS和SULTR在洋麻感染HCRSV後30天之內的關聯性。相較於ATPS，在HCRSV感染後SULTR與miR395有較強的負關聯性（stronger negative correlation）。吾人先前的研究顯示了HCRSV感染後的亞硫酸氧化酶（SO）調控機制，因此以農桿菌滲入法（agroinfiltration）進行SO超表达與基因靜默等實驗以評估SO對SED效應的影響。實驗結果顯示當SO被超表达時會正向調控（upregulate）miR395和它的目標基因ATPS和SULTR；當SO被靜默時則會反向調控（downregulate）之。本研究揭示ATPS與SULTR的正向調控是SO累積加速SED效應的結果，此有助於進一步了解SED參與病毒感染過程的機制。

並列摘要

Previous results showed that interaction of Hibiscus chlorotic ringspot virus (HCRSV) coat protein (CP) and sulfite oxidase (SO) triggers sulfur enhanced defence (SED). MicroRNA395 (miR395), which targets genes ATP sulfurylase (ATPS) and sulfate transporter (SULTR), is the only reported miRNA to be involved in the sulfur metabolism pathway. ATPS and SULTR are two enzymes involved in producing glutathione and transporting sulfate, respectively, in the SED pathway. Hibiscus cannabinus L. (kenaf) was used as an experimental host for studies of HCRSV. In this study, we investigated the correlation of miR395 and its target genes ATPS and SULTR in HCRSV-infected kenaf within 30 days. SULTR showed a stronger negative correlation with miR395 as compared to ATPS after HCRSV infection. Since our previous results showed an upregulation of SO after HCRSV infection, SO overexpression and silencing experiments were carried out to evaluate the effects of SO on the SED effect using agroinfiltration. The miR395 and its target genes ATPS and SULTR were found to be upregulated or downregulated when SO was overexpressed or silenced, respectively. Therefore, this study demonstrated that upregulation of ATPS and SULTR, which are the consequences of SO accumulation facilitates the SED effect. This study contributes to a better understanding of the involvement of the SED pathway in virus infection. (210 words)

並列關鍵字

HCRSV ； miR395 ； ATPS ； SULTR ； SED