Department of Plant Pathology, Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA.
Virology. 2014 Jan 5;448:274-83. doi: 10.1016/j.virol.2013.10.017. Epub 2013 Nov 8.
We examined the limits of manipulation of the Citrus tristeza virus (CTV) genome for expressing foreign genes in plants. We previously created a vector with a foreign gene cassette inserted between the major and minor coat protein genes, which is position 6 from the 3' terminus. Yet, this virus has 10 3'-genes with several other potential locations for expression of foreign genes. Since genes positioned closer to the 3' terminus tend to be expressed in greater amounts, there were opportunities for producing greater amounts of foreign protein. We found that the virus tolerated insertions of an extra gene in most positions within the 3' region of the genome with substantially increased levels of gene product produced throughout citrus trees. CTV was amazingly tolerant to manipulation resulting in a suite of stable transient expression vectors, each with advantages for specific uses and sizes of foreign genes in citrus trees.
我们研究了操纵柑橘衰退病毒（CTV）基因组在植物中表达外源基因的极限。我们之前创建了一个带有外源基因盒的载体，该基因盒插入在主要和次要外壳蛋白基因之间，位于 3' 末端的第 6 位。然而，这种病毒有 10 个 3' 基因，还有其他几个可能的位置可以表达外源基因。由于靠近 3' 末端的基因表达量往往更大，因此有机会产生更多的外源蛋白。我们发现，病毒在基因组 3' 区域的大多数位置都能耐受额外基因的插入，在柑橘树中产生的基因产物水平显著增加。CTV 对外源基因的操纵具有惊人的耐受性，从而产生了一系列稳定的瞬时表达载体，每个载体都具有在柑橘树上使用特定大小的外源基因的优势。
