Expression of Poplar Chitinase in Tomato Leads to Inhibition of Development in Colorado Potato Beetle

Abstract

The previously described poplar chitinase, WIN6, is induced during infestation by gypsy moth (Lymantria dispar L.) larvae, thus suggesting a role in defense against insect pests. To test this hypothesis, we produced tomato seedlings infected with a recombinant potato virus X (PVX), which produces WIN6, and tested its insecticidal properties on Colorado potato beetle [CPB; Leptinotarsa decemlineata (Say)], which is a serious pest of tomatoes and other crops. The advantage of PVX is that plant material is ready for insect bioassay within 3-4 weeks of constructing the recombinant virus. Considering that production of transgenic tomato seedlings using Agrobacterium takes at least 6 months, this hastens the rate at which genes can be examined. Upon insect bioassay, only 47% CPB neonates feeding on leaves containing >0.3% w/w WIN6 developed to 2nd instar while 93% of controls reached 2nd instar. To our knowledge this is the first plant chitinase that retards development of an insect pest.

Cloning and Characterization of a Balsam Pear Class I Chitinase Gene (Mcchit1) and Its Ectopic Expression Enhances Fungal Resistance in Transgenic Plants

“…[2][3][4][5][6][7][8] Many chitinases have been expressed in various plants to enhance resistance against fungal disease, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and also resistance to spiders and insects. [20][21][22] When a powerful fungal endochitinase from a mycoparasitic fungus, Trichoderma, was expressed, the transgenic plants showed high resistance to a broad spectrum of fungal pathogens. [10][11][12]14,15) However, it was frequently found that expressing a single chitinase gene enhanced resistance only against a limited number of pathogens and/or to an inadequate level in transgenic plants, [3][4][5][6][7] which is probably to be attributed to the low chitinolytic and antifungal activities of the chitinases in question.…”

Effects on lepidopteran herbivores of feeding on leaves of transgenic birch (Betula pendula) expressing the sugar beet chitinase IV gene

“…This indicates that the conversion of absorbed nutrients into caterpillar biomass was the lowest for those O. antiqua larvae fed leaves with a high chitinase expression. Some earlier studies show that transgenic chitinase may have a strong effect on insect growth and development (Regev et al, 1996;Lawrence & Novak, 2006;Corrado et al, 2008). The transgenic chitinase may affect lepidopteran larvae directly by damaging the peritrophic membrane (PM) lining the gut of insects (Kramer & Muthukrishnan, 1997;Lawrence & Novak, 2006).…”

“…Some earlier studies show that transgenic chitinase may have a strong effect on insect growth and development (Regev et al, 1996;Lawrence & Novak, 2006;Corrado et al, 2008). The transgenic chitinase may affect lepidopteran larvae directly by damaging the peritrophic membrane (PM) lining the gut of insects (Kramer & Muthukrishnan, 1997;Lawrence & Novak, 2006). Insect growth and development is very dependent on their capability of quickly remodelling the chitinous structures in peritrophic matrices just before moulting.…”

“…Lepidoptera fed on transgenic plants expressing chitinase originating from a plant, insect or virus are adversely affected (Ding et al, 1998;Wang et al, 2005;Fiandra et al, 2010) to varying degrees (Gatehouse et al, 1997;Jouanin et al, 1998;Schuler et al, 1998). Transgenic tobacco expressing chitinase originating from poplar inhibit the development of Colorado potato beetle (Leptinotarsa decemlineata) (Lawrence & Novak, 2006) and transgenic (viral) chitinase also reduces the damage caused by fungal pathogens and lepidopterous larvae (Corrado et al, 2008), which indicates that transgenic chitinases adversely affect lepidopterous larvae. However, the performance of aphids infesting transgenic plants expressing chitinase is improved (Saguez et al, 2005;Vihervuori et al, 2008).…”

Use of a detached leaf screening method for segregating Colorado potato beetle (Leptinotarsa decemlineata Say) resistant Solanum hybrid lines

“…L.) (Zvereva and Kozlov 1996), cucumber beetle (Diabrotica balteata LeConte) on lettuce (Lactuca sativa L.) (Huang et al 2003a), other chrysomelid beetles on corn (Zea mays L.) (Risch 1985) and Colorado potato beetle on tomato (Lycopersicon esculentum Mill.) (Lawrence and Novak 2006).…”