BEIJING, April 13 (Xinhua) -- A novel plant-derived insecticidal protein named iJAZ has moved from the laboratory to practical application, providing a self-reliant and controllable technological route for insect-resistant breeding in China, the Science and Technology Daily has reported.
The Institute of Cotton Research (ICR) of the Chinese Academy of Agricultural Sciences signed a cooperative agreement with Guangxi Tianyuan Biochemistry Co., Ltd. to jointly develop insect-resistant bio-breeding research on four major crops, including cotton, soybean, eucalyptus and sugarcane, to promote the widespread application of this novel insect-resistant technology.
The iJAZ is naturally found in a variety of plants such as cotton, pumpkin and durian. The protein demonstrates broad-spectrum insecticidal activity against particular pests, operating in a completely different mechanism from that of the widely adopted Bacillus thuringiensis (Bt) insecticidal protein.
The iJAZ remains silent under normal conditions. Only when the targeted pests feed on and cause damage to plant leaves does the protein specifically recognize and precisely bind to the unique receptors in the pests' guts, thereby exerting its efficient insecticidal effect, according to the ICR.
Research results indicate that the iJAZ exhibits a resistance rate of 99.33 percent against cotton bollworm larvae. Moreover, such a protein is only one-tenth the size of the Bt protein, and the two can be applied together.
This approach provides an effective solution to the industry-wide problem of resistance degradation of the Bt protein.
In addition, the researchers from the ICR developed a high-efficiency genetic transformation system, which induces direct shoot formation from apical stem cells of seeds, and can be deployed alongside the iJAZ application.
This technological system drastically shortens the transformation cycle from 6 to 8 months to 2 to 3 months. More importantly, it overcomes the genotype barrier, enabling scientists to take a tailored approach to equipping the elite commercial varieties with insect-resistant "armors" and accelerate the breeding process of new insect-resistant varieties.
The system has been successfully extended to a variety of crops, including soybean, peanut, cucumber and cowpea, the ICR said. ■
