A critical appraisal of non conventional resistance to plant viruses
G.P. Martellihttps://doi.org/10.17221/10311-PPSCitation:Martelli G.P. (2002): A critical appraisal of non conventional resistance to plant viruses. Plant Protect. Sci., 38: S15-S20.
Among natural resistance mechanisms to plant pathogens, cultivar resistance has been extensively used in plant breeding to introduce what can be defined as “conventional” resistance to a number of them, including viruses. The necessity of overcoming the constraints of genetic incompatibility, so as to widen the range of possibile use of genetic control of infectious agents, has propitiated the utilization of biotechnological procedures, whereby “non conventional” or transgenic resistance was developed. Transgenic resistance to plant viruses encompasses the identification, cloning and tranferring into the recipient host of single viral genes, which gives rise to what is known as “pathogen-derived resistance” (PDR). Of the hypothesized mechanisms underlying expression of PDR, post-transcriptional gene silencing has been most extensively investigated in recent years. Despite of the success that virus-resistant cropping of transgenic plants begins to enjoy, in Europe there is still a widespread sentiment against agricultural biotechnologies and the use of genetically modified plants in particular. Yet, experimental evidence is accumulating that, in the case of PDR, the feared risks associated with genetic trasformation are minimal, if not negligibleKeywords:
genetic engineering; transgenic resistance; biotechnology; virus; gene silencing