Can transgenic virus resistance work in the real world ¨C what about TSWV?
D Gonsalves
ARS/USDA Pacific Basin Agricultural Research Center, 99 Aupuni Street, Suite 204, Hilo, Hawaii 96720, USA.
Correspondence: dgonsalves@pbarc.ars.usda.gov
Nearly 20 years ago, our laboratory embarked on developing virus resistant transgenic plants. The major viruses we focused on were papaya ringspot virus, tomato spotted wilt virus, and other vegetable viruses such as zucchini yellow mosaic, cucumber mosaic, and watermelon mosaic virus II. I will focus this talk on papaya ringspot virus and tospoviruses because they may present several lessons that will help to answer the question: Can Transgenic Virus Resistance Work in the Real World? The papaya work shows that transgenic virus resistance can work on a commercial scale and actually helped to save the papaya industry in Hawaii. Aside from the technical aspects, it also shows that timing and implementation of a transgenic product is important. One might say that the transgenic papaya was developed and commercialized before the ¡®days of innocence¡¯ with GMOs ended somewhere in 1998. To the present day, the papaya work also illustrates the type of forces or circumstances that affect the timely deployment of transgenic papaya outside of Hawaii. Relatively speaking, however, the papaya work did not shed as much light on the mechanism of transgenic virus resistance. In contrast, the work on tospoviruses did provide some insights on the mechanism and potential of transgenic tospovirus resistance. Given the range of crops that tospoviruses infect, one would expect that tospovirus resistance for commercial reasons might be a promising area of endeavor. However, I have not yet seen any signs that transgenic tospovirus resistance will be used commercially in the near future. Why is this? Is it because of technical difficulties? Is it because of the lack of will to do it? Or does the present GMO controversy suggest that the timing is not good for introducing tospovirus resistance to the real world? I will briefly discuss these aspects as they interrelate with my laboratory¡¯s experience on papaya ringspot virus and tospoviruses.
