Development of Bt Rice and Bt Maize in China and Their Efficacy in Target Pest Control

Abstract

Rice and maize are important cereal crops that serve as staple foods, feed, and industrial material in China. Multiple factors constrain the production of both crops, among which insect pests are an important one. Lepidopteran pests cause enormous yield losses for the crops annually. In order to control these pests, China plays an active role in development and application of genetic engineering (GE) to crops, and dozens of GE rice and GE maize lines expressing insecticidal proteins from the soil bacterium Bacillus thuringiensis (Bt) have been developed. Many lines have entered environmental release, field testing, and preproduction testing, and laboratory and field experiments have shown that most of the Bt rice and Bt maize lines developed in China exhibited effective control of major target lepidopteran pests on rice (Chilo suppressalis, Scirpophaga incertulas, and Cnaphalocrocis medinalis) and maize (Ostrinia furnacalis), demonstrating bright prospects for application. However, none of these Bt lines has yet been commercially planted through this writing in 2016. Challenges and perspectives for development and application of Bt rice and maize in China are discussed. This article provides a general context for colleagues to learn about research and development of Bt crops in China, and may shed light on future work in this field.

Transgenic microRNA‐14 rice shows high resistance to rice stem borer

“…The widely used transgenic Bt cotton is a successful example of controlling insecticide‐resistant insect pests (Wu et al ., ). Many insect‐resistant Bt rice lines have been developed, although they are not commercially planted so far (Liu et al ., ). Transgenic Bt rice showed high resistance to early‐instar larvae of RSB (90%–100% mortality; Liu et al ., ), however, the mortalities significantly decreased when feeding it to higher instar larvae (Hu et al ., ).…”

“…For the field trial assay, the percentage of rice plants with dead‐heart was taken as the main indicator of damage caused by RSB (Liu et al ., ; Shu et al ., ). To examine the resistance of amiR‐14 transgenic rice plants to RSB in laboratory, 30 newly hatched RSB larvae were transferred to limited numbers of whole rice plants at the booting stage (60‐days old) using a small brush and kept in nylon mesh cages (80‐cm in length and 18‐cm in diameter).…”

“…In the past two decades, transgenic Bt cotton has been widely adopted as a GM insect‐resistant crop (Li et al ., ). In China, dozens of Bt rice and Bt maize lines have been developed, some of which showed high efficiency in controlling target lepidopteran pests on rice (Liu et al ., ). Botanically derived insecticidal genes, such as Galanthus nivalis agglutinin (GNA; Rao et al ., ), and protein inhibitor genes (e.g., pin II , CpTi , SKTI and BTI‐CMe ) were also used to produce various GM crops resistant against to herbivory planthoppers, stem borers and rice water weevils (Alfonso‐Rubi et al ., ; Duan et al ., ; Lee et al ., ; Xu et al ., ).…”

Consumption of Bt Maize Pollen Containing Cry1Ie Does Not Negatively Affect Propylea japonica (Thunberg) (Coleoptera: Coccinellidae)

“…To date, China has obtained many Bt maize lines, all of which express cry1 and/or cry2 genes targeting lepidopteran pests [4,5,6,7]. Most of the Bt maize lines, such as IE09S034 (expressing a cry1Ie gene), BT-799 (expressing a modified mcry1Ac gene), and Shuangkang12-5 (expressing a fusion cry1Ab/2Aj gene) have proven to be effective against lepidopteran pests [8,9].…”

CRISPR/Cas9‐based mutation reveals Argonaute 1 is essential for pigmentation in Ostrinia furnacalis

“…Ostrinia furnacalis (Lepidoptera: Pyralidae) is one of the most destructive pests of maize, especially in Asia (Liu et al, 2016). However, management of O. furnacalis using traditional methods is not effective and novel genetic pest management tools are urgently needed.…”