3 Potential Risks Associated with Virus

The following points highlight the three potential risks associated with virus. The risks are: 1. Environmental Issue 2. Health Issue 3. Virus Overcoming Transgenic Resis­tance.

Virus: Potential Risk # 1.

Environmental Issue:

Environmental safety issues have also been expressed with regard to the transfer of virus genes from transgenic crops into compatible plant species through pollination. It is not impossible that an otherwise susceptible plant could become resistance to virus in­fection upon successful hybridization.

As a consequence, hybrid progeny could have an increased fitness and eventually be­come more competitive in their habitat. This even may give birth to some highly potent weeds which can grow rampantly taking over the commercial crops.

Virus: Potential Risk # 2.

Health Issue:

Effects of virus-resistant transgenic crops on human health relate essentially to allergen city in terms of the properties of proteins encoded by virus gene segments expressed in transgenic plants. Theoretically, virus-transgene pro­tein products can have stretches of amino acid sequences that are identical to poten­tial epitopes of allergen proteins.

As a con­sequence, transgenic plants expressing virus-gene fragments could promote al­lergy in people coming in contact with the products of such transgenic plants.

Virus: Potential Risk # 3.

Virus Overcoming Transgenic Resis­tance:

Some virus strains are able to over­come engineered resistance because RNA silencing is a defense mechanism based on nucleotide sequence identities. Resistance is more likely to be achieved against virus strains with high sequence homology to the strain(s) from which transgenes are de­rived than those that are most distantly related. In addition, viruses encode some proteins that can act as suppressors of RNA silencing.

This means that viruses can counteract the plant’s defense mecha­nism by interfering with some key steps of the antiviral pathways that lead to re­sistance. Also, the plant developmental stage and features of virus-derived transgenes, among other factors, can in­fluence the effectiveness of RNA silencing.

In other words, activation and regulation of the antiviral pathways of RNA silenc­ing is dynamic. Therefore, monitoring the introduction of virus-resistant transgenic crops and eventual emergence of new vi­ral strains is key to maximize the effec­tiveness and durability of engineered vi­rus resistance.