A dna fragment with insecticidal effect and its application in agriculture

Abstract

The invention relates to a DNA fragment having an insecticidal effect and agricultural application of the DNA fragment, belonging to the technical field of biological transgenosis. The DNA fragment having the insecticidal effect consists of a signal peptide sequence, a toxin protein sequence, a phytolectin sequence and an auxiliary sequence; the DNA fragment having the insecticidal effect is formed by linking the spider toxin sequence and the phytolectin sequence which take an insecticidal effect in a special mode and by adding the auxiliary sequence to increase expression quantity, and the formed DNA fragment has a positive effect in the aspects of pest repelling and control. The agricultural application mode of the DNA fragment includes the follows: DNA is transcribed and translated into fusion protein, or a polynucleotide composition, which is constructed by the DNA fragment and a plant promoter, is transformed and expressed in a plant body so as to form a resistant plant.

Description

Technical field: [0001] The invention belongs to the technical field of biological transgenes, and relates to a DNA segment with insecticidal effect and its application in agriculture. Background technique: [0002] In the 1980s, people have begun to use biotransgenic technology to control pests and cultivate insect-resistant plants. However, until now, the insect-resistant gene is still dominated by the Bacillus thuringiensis toxin gene (Bt). After years of application in cotton, it has been found that sucking pests such as miridae have gradually risen from secondary pests to major pests, mainly because the above-mentioned insect-resistant genes have no obvious effect on sucking mouthparts pests. At the same time, the long-term use of a single insect-resistant gene can lead to an increase in pest resistance, which also limits the further application of such insect-resistant genes. Therefore, the development of a new environmentally friendly and efficient insect-resistant g...

AI Technical Summary

Problems solved by technology

However, due to the barriers of the insect's outer skin and the peritrophic membrane, the spider toxin cannot effectively enter the insect body / ion channel, directly affecting its insecticidal effect. Therefore, chitinase and plant lectin are added to the spider toxin , chitinase can break through the barrier effect of insect outer skin, and plant lectin can bind to the surface of insect peritrophic membrane, glycoconjugates of digestive tract epithelial cells, or glycosylated digestive enzymes to induce lesions in insect digestive tract for the purpose of killing insects

For example: the prior art publication number is the document of CN103154022A, chitinase is connected on the spider poisonous sequence through the secretion signal sequence, and the spider toxin sequence is connected with the plant lectin sequence to reduce the protective effect of the insect exoskeleton, making the spider The toxin acts better on insects. However, linking chitinase and lectin to both ends of the toxin protein will greatly affect the activity of the toxin, because most of the toxin protein is usually at the N-terminus. or C-terminal

In addition, even if the toxin and chitinase are attached to both ends of the lectin, it will also affect the activity of the lectin protein

Therefore, the existing technology is difficult to play the role of fusion protein

[0004] To sum up, the existing method of using spider toxin sequence for transgenic can not give full play to the effect of spider toxin, so a DNA fragment with insecticidal effect is needed, the fragment It can not only realize that the toxin protein sequence has a good repelling and killing effect on piercing-sucking pests and other types of pests, but also ensure the stability of the fragment during gene transfer

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