The extremophile Nicotiana benthamiana has traded viral defence for early vigour
The extremophile Nicotiana benthamiana has traded viral defence for early vigour
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DOI：
10.1038/nplants.2015.165
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发表时间：
2015-11-02
期刊：
影响因子：
18
通讯作者：
Waterhouse, Peter M.
中科院分区：
文献类型：
--
作者：
Bally, Julia;Nakasugi, Kenlee;Waterhouse, Peter M.
本氏烟草（Nicotiana benthamiana）的单一谱系被广泛用作模式植物（1），并且在关于RNA干扰（RNAi）、病毒防御和疫苗生产的革命性发现中发挥了重要作用。它对病毒的易感性和瞬时表达转基因的顺从性是无与伦比的（2，3）。这些无与伦比的特征与RNA依赖性RNA聚合酶1基因Rdr1中的破坏性插入有正相关和负相关（4 - 6）。对于一种经常用于研究的植物来说，物种的起源，多样性和进化，以及其不寻常能力的基础，相对而言尚未探索。在这里，通过与来自该物种自然分布范围内的野生种质进行比较，我们表明，N。benthamiana是一种极端微生物，来自一个种群，该种群在Rdr1中保留了大约80万年的突变，从而在澳大利亚中部的极端生境中以其防御能力换取了早期活力和生存。在该分离株中重建Rdr1活性提供了保护。沉默野生菌株中的功能等位基因使其变得敏感，并与种子大小加倍和早期生长速率增强有关。这些发现为更深入地了解保护与活力之间的微妙平衡开辟了道路。
A single lineage of Nicotiana benthamiana is widely used as a model plant(1) and has been instrumental in making revolutionary discoveries about RNA interference (RNAi), viral defence and vaccine production. It is peerless in its susceptibility to viruses and its amenability in transiently expressing transgenes(2,3). These unparalleled characteristics have been associated both positively and negatively with a disruptive insertion in the RNA-dependent RNA polymerase 1 gene, Rdr1(4-6). For a plant so routinely used in research, the origin, diversity and evolution of the species, and the basis of its unusual abilities, have been relatively unexplored. Here, by comparison with wild accessions from across the spectrum of the species' natural distribution, we show that the laboratory strain of N. benthamiana is an extremophile originating from a population that has retained a mutation in Rdr1 for similar to 0.8 Myr and thereby traded its defence capacity for early vigour and survival in the extreme habitat of central Australia. Reconstituting Rdr1 activity in this isolate provided protection. Silencing the functional allele in a wild strain rendered it hypersusceptible and was associated with a doubling of seed size and enhanced early growth rate. These findings open the way to a deeper understanding of the delicate balance between protection and vigour.