Authors: Chengxiang Qiu Jatinder Singh Sangha Fengshun Song Zhiyun Zhou Ao Yin Keyu Gu Dongsheng Tian Jianbo Yang Zhongchao Yin
Publish Date: 2010/07/01
Volume: 29, Issue: 10, Pages: 1097-1107
Abstract
The hybrid Bacillus thuringiensis Bt δendotoxin gene Cry1Ab/Ac was used to develop a transgenic Bt rice Oryza sativa L targeting lepidopteran insects of rice Here we show the production of a markerfree and tissuespecific expressing transgenic Bt rice line L24 using Agrobacteriummediated transformation and a chemically regulated Cre/loxPmediated DNA recombination system L24 carries a single copy of markerfree TDNA that contains the Cry1Ab/Ac gene driven by a maize phosphoenolpyruvate carboxylase PEPC gene promoter The markerfree TDNA was integrated into the 3′ untranslated region of rice gene Os01g0154500 on the short arm of chromosome 1 Compared to the constitutive and nonspecific expression of the P Actin1 Cry1Ab/AcT Nos gene in the control Bt rice line T511 the P Pepc Cry1Ab/AcT Nos gene was detected only in the leaf and stem tissues of L24 More importantly compared to high levels of CRY1Ab/Ac proteins accumulated in T511 seeds the CRY1Ab/Ac proteins were not detectable in L24 seeds by Western blot analysis As demonstrated by insect bioassay L24 provided similar level of resistance to rice leaffolder Cnaphalocrocis medinalis as T511 The markerfree transgenic line L24 can be used directly in rice breeding for insect resistance to lepidopteran insects where absence of Bt toxin protein in the seed is highly desirableThe authors thank Yunlu Fan for providing plasmid pFWZ16 and Qifa Zhang for providing Bt line T511 This work was supported by intramural research funds from Temasek Life Sciences Laboratory ZY The authors declare that they have no conflict of interest
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