Engineering virus resistance using a modified potato gene

Abstract

Summary Natural mutations in translation initiation factor eIF4E confer resistance to potyviruses in many plant species. Potato is a staple food crop plagued by several potyviruses, yet to date no known eIF4E‐mediated resistance genes have been identified. In this study, we demonstrate that transgenic expression of the pvr12 gene from pepper confers resistance to Potato virus Y (PVY) in potato. We then use this information to convert the susceptible potato ortholog of this allele into a de novo allele for resistance to PVY using site‐directed mutagenesis. Potato plants overexpressing the mutated potato allele are resistant to virus infection. Resistant lines expressed high levels of eIF4E mRNA and protein. The resistant plants showed growth similar to untransformed controls and produced phenotypically similar tubers. This technique disrupts a key step in the viral infection process and may potentially be used to engineer virus resistance in a number of economically important plant–viral pathosystems. Furthermore, the general public may be more amenable to the ‘intragenic’ nature of this approach because the transferred coding region is modified from a gene in the target crop rather than from a distant species.

Exploring natural variations in eIF4E and screening for potyviral resistance in diverse Nicotiana species

“…In the case of potato, which is a member of the same Solanaceae family as with Nicotiana species, no natural variations responsible for PVY resistance were detected. However, genetically modified potatoes overexpressing mutated potato-eIF4E were designed, based on the variations which exist in pepper eIF4E causing PVY resistance gained against several PVY strains (Cavatorta et al, 2011). Therefore, it is still plausible that translation initiation factors eIF4E or/and eIF(iso)4E play(s) roles in potyviral susceptibility or resistance in Nicotiana plants, although no natural variations causing viral resistance were detected in this study.…”

“…Mutagenic analysis on eIF4E or (and) its paralogue eIF(iso)4E was effective to obtain potyviral resistance in various plants including Arabidopsis (Cavatorta et al, 2011;Lellis et al, 2002;Mazier et al, 2011;Piron et al, 2010;Ruffel et al, 2006;Sato et al, 2005). Moreover, eIF(iso)4G, another translation initiation factor, turned out to be involved in potyviral resistance in rice (Albar et al, 2006).…”

Resistance to viruses of potato: current status and prospects

“…Так, в случае экспрессии в растениях S. tuberosum гена фактора eIF4E, который со держит замены, совпадающие с таковыми в гене pvr12 стручкового перца, устойчивого к PVY, полученные транс генные растения также демонстрировали устойчивость к данному вирусу (Cavatorta et al, 2011).…”

Biotech Potatoes in the 21st Century: 20 Years Since the First Biotech Potato

“…In pepper and tomato, eIF4E-mediated resistance is inherited in a recessive manner (Ruffel et al 2002(Ruffel et al , 2005. However, introduction of the pepper gene into tomato or potato results in resistance that is dominant over the expression of the endogenous eIF4E variant (Kang et al 2007;Cavatorta et al 2011), demonstrating that deployment of eIF4E-based resistance from wild relatives into tetraploid potato is feasible without the need for removal or silencing of the endogenous susceptible allele. The mechanism by which the introduction of this eIF4E using biotechnology results in a switch from recessive to dominant resistance is not well understood and is currently a focus of multiple research projects.…”

“…One such example is the eIF4E gene that has been found to be associated with virus resistance in many plant species (Nicaise et al 2003;Gao et al 2004;Yoshii et al 2004;Kang et al 2005;Kanyuka et al 2005;Stein et al 2005;Nieto et al 2006Nieto et al , 2007Ibiza et al 2010;Naderpour et al 2010;Piron et al 2010), including resistance to potato virus Y in potato, tomato, and pepper (Ruffel et al 2002(Ruffel et al , 2005Cavatorta et al 2011;Duan et al 2012). Variants of eIF4E confer resistance to PVY in the potato wild species relatives S. chacoense, S. demissum, and S. etuberosum , permitting the eventual use of this gene in future biotech potato varieties.…”