A TILLING approach to generate broad-spectrum resistance to potyviruses in tomato is hampered by eIF4E gene redundancy

作者：Gauffier Camille; Lebaron Caroline; Moretti Andre; Constant Carole; Moquet Frederic; Bonnet Gregori; Caranta Carole; Gallois Jean Luc

来源：Plant Journal, 2016, 85(6): 717-729.

DOI：10.1111/tpj.13136

<jats:title>Summary</jats:title><jats:p>Genetic resistance to pathogens is important for sustainable maintenance of crop yields. Recent biotechnologies offer alternative approaches to generate resistant plants by compensating for the lack of natural resistance. Tomato (<jats:italic>Solanum lycopersicum</jats:italic>) and related species offer a model in which natural and <jats:styled-content style="fixed-case">TILLING</jats:styled-content>‐induced potyvirus resistance alleles may be compared. For resistance based on translation initiation factor eIF4E1, we confirm that the natural allele <jats:italic>Sh–eIF4E1</jats:italic><jats:sup><jats:italic>PI24</jats:italic></jats:sup><jats:italic>–pot1</jats:italic>, isolated from the wild tomato species <jats:italic>Solanum habrochaites</jats:italic>, is associated with a wide spectrum of resistance to both potato virus Y and tobacco etch virus isolates. In contrast, a null allele of the same gene, isolated through a <jats:styled-content style="fixed-case">TILLING</jats:styled-content> strategy in cultivated tomato <jats:italic>S. lycopersicum</jats:italic>, is associated with a much narrower resistance spectrum. Introgressing the null allele into <jats:italic>S. habrochaites</jats:italic> did not extend its resistance spectrum, indicating that the genetic background is not responsible for the broad resistance. Instead, the different types of eIF4E1 mutations affect the levels of eIF4E2 differently, suggesting that <jats:italic>eIF4E2</jats:italic> is also involved in potyvirus resistance. Indeed, combining two null mutations affecting <jats:italic>eIF4E1</jats:italic> and <jats:italic>eIF4E2</jats:italic> re‐establishes a wide resistance spectrum in cultivated tomato, but to the detriment of plant development. These results highlight redundancy effects within the <jats:italic>eIF4E</jats:italic> gene family, where regulation of expression alters susceptibility or resistance to potyviruses. For crop improvement, using loss‐of‐function alleles to generate resistance may be counter‐productive if they narrow the resistance spectrum and limit growth. It may be more effective to use alleles encoding functional variants similar to those found in natural diversity.</jats:p>

• 出版日期2016-3