2020年10月9日發(fā)表于《科學(xué)》雜志上的“WUSCHEL triggers innate antiviral immunity in plant stem cells”揭示了植物干細(xì)胞是如何抵御病毒侵染的分子機(jī)制。

Building a safe space for stem cells
The meristem, the collection of stem cells that builds plants, is resistant to viral infection. Wu et al. now show that WUSCHEL, a transcription factor that helps to sustain stem cell production in the shoot apical meristem of Arabidopsis, also protects that stem cell domain from viruses. WUSCHEL inhibited viral protein synthesis by repressing methyltransferases that regulate ribosomal RNA processing and ribosome stability.
Abstract
Stem cells in plants constantly supply daughter cells to form new organs and are expected to safeguard the integrity of the cells from biological invasion. Here, we show how stem cells of the Arabidopsis shoot apical meristem and their nascent daughter cells suppress infection by cucumber mosaic virus (CMV). The stem cell regulator WUSCHEL responds to CMV infection and represses virus accumulation in the meristem central and peripheral zones. WUSCHEL inhibits viral protein synthesis by repressing the expression of plant S-adenosyl-L-methionine–dependent methyltransferases, which are involved in ribosomal RNA processing and ribosome stability. Our results reveal a conserved strategy in plants to protect stem cells against viral intrusion and provide a molecular basis for WUSCHEL-mediated broad-spectrum innate antiviral immunity in plants.

植物干細(xì)胞的先天抗病毒免疫

解析WUS介導(dǎo)干細(xì)胞免疫病毒的分子機(jī)制，作者發(fā)現(xiàn)WUS蛋白可以直接抑制一類(lèi)核糖體RNA甲基轉(zhuǎn)移酶基因（S-adenosyl-L-methionine-dependent methyltransferases），影響rRNA的加工和核糖體的穩(wěn)態(tài)，進(jìn)而可以抑制病毒蛋白質(zhì)的合成。為了研究WUS介導(dǎo)的干細(xì)胞抗病毒免疫是否具有廣譜性，該研究還檢查了其他三種植物病毒，得到了一致的結(jié)論。

該研究揭示了植物莖頂端分生組織存在廣譜抗病毒免疫的分子機(jī)制。在侵染過(guò)程中，病毒必須利用植物細(xì)胞內(nèi)的蛋白質(zhì)合成系統(tǒng)合成自身的蛋白，以完成自身的復(fù)制、組裝和侵染過(guò)程。而干細(xì)胞關(guān)鍵調(diào)節(jié)基因WUS則通過(guò)直接抑制細(xì)胞內(nèi)蛋白質(zhì)合成的速率，限制了病毒的復(fù)制和傳播（如圖）。為作物抗病毒防治提供了新的思路。