Billion dollar bad bug: Ostrinia nubilalis Hubner, order Lepidoptera, a.k.a. European Corn Borer
Insect pests are a major factor in the loss of the world's agricultural crops. For example, armyworm feeding, black cutworm damage, or European corn borer damage can be economically devastating to agricultural producers. Insect pest-related crop loss from European corn borer attacks on field and sweet corn alone has reached about one billion dollars a year in damage and control expenses.
Pioneer Hi-Bred International, Inc. (Johnston, IA) scientists created biopesticides with improved insecticidal activity that may be genetically encoded into plants for greater protection against insects without resorting to chemical pesticides. According to inventors Andre R. Abad, Hua Dong, Sue B. Lo And Xiaomei Shi the discovery relates to naturally-occurring and recombinant nucleic acids obtained from novel Bacillus thuringiensis genes which can encode plants with polypeptides characterized by pesticidal activity against insect pests. Compositions and methods revealed in U.S. Patent Application 20090313722 utilize nucleic acids, and their encoded pesticidal polypeptides, to control plant pests.
The discovery fills a need for new Bt toxins with a broader range of insecticidal activity against insect pests, e.g., toxins which are active against a greater variety of insects from the order Lepidoptera (butterflies and moths). In addition, it meets a need for biopesticides with activity against a variety of insect pests and for biopesticides which have improved insecticidal activity. The discovery relates to methods of impacting insects utilizing nucleotide sequences encoding insecticidal peptides to produce transformed microorganisms and plants that express a insecticidal polypeptide. Such pests include agriculturally significant pests, such as, for example: European corn borer e.g. Ostrinia nubilalis Hubner.
The nucleotide sequences encode polypeptides that are pesticidal for at least one insect belonging to the order Lepidoptera (butterflies and moths). The embodiments provide a nucleic acid and fragments and variants which encode polypeptides that possess pesticidal activity against insect pests (e.g. SEQ ID NO: 1 encoding SEQ ID NO: 2). The wild-type (e.g., naturally occurring) nucleotide sequence of the embodiments, which was obtained from Bt, encodes a novel insecticidal peptide.
The embodiments further provide fragments and variants of the disclosed nucleotide sequence that encode biologically active (e.g., insecticidal) polypeptides. The inventors further provide isolated pesticidal (e.g., insecticidal) polypeptides encoded by either a naturally occurring, or a modified (e.g., mutagenized or manipulated) nucleic acid. In particular examples, pesticidal proteins include fragments of full-length proteins and polypeptides that are produced from mutagenized nucleic acids designed to introduce particular amino acid sequences into the polypeptides.
The polypeptides have enhanced pesticidal activity relative to the activity of the naturally occurring polypeptide from which they are derived. The nucleic acids can also be used to produce transgenic (e.g., transformed) monocot or dicot plants that are characterized by genomes that comprise at least one stably incorporated nucleotide construct comprising a coding sequence operably linked to a promoter that drives expression of the encoded pesticidal polypeptide. The inventors also reveal transformed plant cells, plant tissues, plants, and seeds with the pesticidal polypeptide.
Traditionally, the primary method for impacting insect pest populations is the application of broad-spectrum chemical insecticides. However, consumers and government regulators alike are becoming increasingly concerned with the environmental hazards associated with the production and use of synthetic chemical pesticides. Because of such concerns, regulators have banned or limited the use of some of the more hazardous pesticides. Thus, there is substantial interest in developing alternative pesticides.
Biological control of insect pests of agricultural significance using a microbial agent, such as fungi, bacteria, or another species of insect affords an environmentally friendly and commercially attractive alternative to synthetic chemical pesticides. Generally speaking, the use of biopesticides presents a lower risk of pollution and environmental hazards, and biopesticides provide greater target specificity than is characteristic of traditional broad-spectrum chemical insecticides. In addition, biopesticides often cost less to produce and thus improve economic yield for a wide variety of crops.
