PLANT RESISTANCE Combining Engineered Resistance, Avidin, and Natural Resistance Derived From Solanum chacoense Bitter to Control Colorado Potato Beetle (Coleoptera: Chrysomelidae) SUSANNAH G. COOPER, 1 DAVID S. DOUCHES, 1,2 AND EDWARD J. GRAFIUS 3 J. Econ. Entomol. 102(3): 1270Ð1280 (2009) ABSTRACT The Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomeli- dae), is the most destructive insect pest of potato, Solanum tuberosum (L.), in North America. Avidin sequesters available biotin, thereby causing abnormal growth and development of insects. We ex- pressed avidin in two potato lines: MSE149-5Y, a susceptible potato line, and ND5873-15, a line with S. chacoense-derived insect resistance. A preliminary study was conducted to determine the bioactivity of the transgene in each background. A single transgenic line was selected in each background for further studies. Detached leaf bioassays were performed on transgenic and nontransgenic clones of the susceptible and S. chacoense lines by using Þrst-stage Colorado potato beetle larvae. Consumption, survival, and survivor growth were measured after 5 d. Larvae consumed signiÞcantly less on the two avidin-expressing lines compared with the nontransgenic lines. Survival was also signiÞcantly less for larvae feeding on transgenic avidin lines compared with the nontransgenic lines. The mass of survivors was signiÞcantly reduced on two transgenic avidin lines compared with the nontransgenic lines. Further studies examined the development from Þrst-stage larvae to adulthood on greenhouse-grown whole plants in a no-choice setting for larvae fed on the four potato lines. Development from Þrst stage to pupation was signiÞcantly prolonged for larvae fed on the avidin line compared with larvae fed on the susceptible line. SigniÞcantly fewer larvae fed on transgenic avidin plants, avidin or avidin + S. chacoense-derived line survived to adulthood compared with survival on nontransgenic plants, sus- ceptible or S. chacoense-derived line. Avidin-based resistance may be useful in managing Colorado potato beetle populations in commercial planting by reducing the population size. KEY WORDS Solanum tuberosum, Leptinotarsa decimlineata, host plant resistance, transformation Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is a pest of po- tatoes, Solanum tuberosum (L.), in North America, Europe, and Asia. As little as 12.5% defoliation can signiÞcantly reduce yields (Mailloux et al. 1996). If left uncontrolled, Colorado potato beetle completely de- foliates potato crops (Hare 1990). It consistently adapts to insecticides and is currently resistant to 40 insecticides (Whalon et al. 2008). At present, most commercial transgenic crops rely on crystalline (Cry) proteins developed from the bac- terium Bacillus thuringiensis (Bt) Berliner for Bt-Cry proteins are highly speciÞc, often only effective against a particular insect order and many times act on only some insect species within the order (Ferre ´ and Van Rie 2002, Whalon and Wingerd 2003). Bt-Cry proteins are grouped into classes according to activity and structure of the protein. Generally, Bt-Cry3, Bt- Cry7, and Bt-Cry8 proteins are active against Co- leoptera and Bt-Cry1 proteins are active against Lep- idoptera (Herrnstadt et al. 1986, Lambert et al. 1992, Sato et al. 1994). To broaden the range of activity, scientists developed hybrid or chimeric Bt genes with domain regions from different classes of Cry proteins (Naimov et al. 2003, Singh et al. 2004, Chen et al. 2006). Avidin is a novel protein that confers broad-spec- trum resistance to arthropod pests, including Lepi- doptera, Coleoptera, Diptera, and Acari (Levinson and Bergmann 1959, Kramer et al. 2000, Burgess et al. 2002). Avidin is a natural protein derived from the chicken (Gallus gallus L.) egg white. It has a strong afÞnity for biotin, with the strongest noncovalent bond found in nature (K d = 10 -15 M) and is able to sequester biotin (Izrailev et al. 1997). Biotin, also called vitamin H or B 8 , is critical for all organisms, including insects (Trager 1948). Many important car- boxylases require biotin as a cofactor, including car- boxylases involved in such important biosynthetic pathways such as the citric acid cycle, lipogenesis, gluconeogensis, and fatty acid and amino acid catab- olism (Mistry and Dakshinamurti 1964). All organisms require biotin, but only some plants, bacteria, and fungi synthesize biotin. Hence, most organisms, in- 1 Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI 48824. 2 Corresponding author, e-mail: douchesd@ msu.edu. 3 Department of Entomology, Michigan State University, East Lan- sing, MI 48824. 0022-0493/09/1270Ð1280$04.00/0  2009 Entomological Society of America Downloaded from https://academic.oup.com/jee/article/102/3/1270/2199213 by guest on 01 March 2022