"La resistenza transgenica indotta dal patogeno: un'applicazione biotecnologica poco utilizzata"

One the many practical applications of transgenesis encompasses the introduction into plants of resistance to viruses mediated by viral genes ("pathogen-derived resistance"). A wide number of plant species has currently been transformed for resistance to more than 50 different viruses belonging to diverse families. However, only two transgenic plant species are grown commercially on a relatively large scale: (i) a papaya cultivar transformed with the coat protein gene of Papaya ringspot virus (PRSV) in the USA and the far east (Taywan, China, Thailand); (ii) a croockneck squash resistant to Zucchini yellow mosaic virus (ZYMV) and to Watermelon mosaic virus 2 (WMV-2) in the USA. The plum cv. Honey sweet resistant to Plum pox virus (PPV) and a french bean cultivar resistant to Bean golden mosaic virus (BGMV) have been deregulated in the USA and Brazil, repectively, and are ready for marketing. Much more successful have been the transgenic crops of five plant species that resist to insects (maize and cotton) or to herbicides (soybean, canola, alfalfa), which constitute the largest part of GM plants being cropped in the world. In 2014, 28 different countries, equally distributed among the "industralized" and the "developing" ones, have invested huge surfaces (ca. 180 million hectares) to GM crops growing. Only five of thesee countries are from Europe (Spain, Portugal, Czech Republic, Romania, Slovakia), giving over to GM maize relatively snall surfaces. The widespread antagonism to the use of genetic transformation, which in Europe is regarded as an ethically reprochable and unsafe practice, it is unlikely to be placated by the scientifically established existence of naturally transgenic plants nor by the possibility of resorting to the use of cisgenesis, i.e. the transfer of single genes between plants of the same species, as it happens with the unconditionally accepted but much longer course of traditional crossing.