Analysis Of Resistance To Aphid In Transgenic Wheat With The Insecticidal Lectin From Snowdrop (Galanthus Nivalis Agglutinin, GNA) Gene And Efficient Wheat Transformation By Electroporation With Ring Electrode

Wheat (Triticum aestivum L.) is an important and a major crop not only in China but also in the world. The product loss of wheat due to insects is very high in recent years. Biotechnology is a valid way on insect control comparing with conventional insecticides. Yumai66 is a new commercial variety of wheat with high yield, desirable grain quality and resistance disease, which had been examined and approved by National Crop Variety Approval Committee in 2003. The yield of Yumai66 in each hectare is 10,812 kilogrammes that is equal to 720.8 kilogrammes per Chinese mu, which has achieved the highest yield level of wheat with desirable grain quality in Huang Huai region of China. However, Yumai66 is susceptible to the infection of aphids. Plant lectin is a family of proteins with specific carbohydrate-binding activity distributing in seeds as well as different types of plant vegetative tissues. On the basis of carbohydrate-binding specificity, plant lectins are proposed to not only functions as nitrogen resource or specific recognition factors, but also involved in defense of plant. Plant lectins have deleterious effects on insects, especially against the members of Homoptera. Toxicity of plant lectins towards nematodes, fungi and virus was also reported. Snowdrop lectin (Galanthus nivalis agglutinin; GNA), as a kind of plant lectins, is belong to monocotyledon mannose-binding lectin that is toxic to sap sucking injurious insects of Homopteran. GNA14 gene has been successfully transferred into a common spring wheat Zhong60634 and a winter wheat "Yumai66" by using the biolistic transformation method in my laboratory. The transgenic plants with good resistance to aphid were obtained either in Zhong60634 or in Yumai66. However, the transformation efficiency by particle bombardment is not only low but expensive, which limits development of molecular breeding. Plasmid DNA was delivered into the tissue of intact wheat immature embryos and transgenic plants with stable integration and inheritance were obtained by a portable and permanent ring electrode which fitted into the wells of 24-well plates in my experiments. A simple, fast, efficient and inexpensive wheat transformation procedure was developed by electroporation with ring electrode-mediated gene transfer, which takes a possibility for molecular breeding via genetic engineering in a large scale. 1. GNA14 gene has been transferred respectively into common spring wheat Zhong60634 and winter wheat Yumai66 by using the biolistic transformation method. Transgenic wheat plants have been obtained in both of the two varieties. PCR and Southern blot analysis confirmed the integration of the foreign gene in the transgenic plants genome. Two transgenic plants (T₀) were obtained from the bombarded 535...