Molecular and Toxicity Analyses of White Granulated Sugar and Other Processing Products Derived From Transgenic Sugarcane

Wenzhi Wang; Benpeng Yang; Juangang Wang; Xiaoyan Feng; Cuilian Feng; Tingting Zhao; Linbo Shen; Qinnan Wang; Zhuandi Wu; Shuzhen Zhang; Zhengqiang Ma

doi:10.3389/fpls.2020.596918

Molecular and Toxicity Analyses of White Granulated Sugar and Other Processing Products Derived From Transgenic Sugarcane

Front Plant Sci. 2020 Nov 26:11:596918. doi: 10.3389/fpls.2020.596918. eCollection 2020.

Authors

Wenzhi Wang^{1

2}, Benpeng Yang², Juangang Wang², Xiaoyan Feng², Cuilian Feng², Tingting Zhao², Linbo Shen², Qinnan Wang³, Zhuandi Wu⁴, Shuzhen Zhang², Zhengqiang Ma¹

Affiliations

¹ Crop Genomics and Bioinformatics Center and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China.
² Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
³ Institute of Bioengineering, Guangdong Academy of Sciences, Guangzhou, China.
⁴ Sugarcane Research Institute, Yunnan Academy of Agricultural Sciences, Kaiyuan, China.

Abstract

This study aimed to prepare the sugar industry for the possible introduction of genetically modified (GM) sugarcane and derived retail sugar products and to address several potential public concerns regarding the characteristics and safety of these products. GM sugarcane lines with integrated Cry1Ab and EPSPS foreign genes were used for GM sugar production. Traditional PCR, real-time fluorescent quantitative PCR (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA) were performed in analyzing leaves, stems, and other derived materials during sugar production, such as fibers, clarified juices, filter mud, syrups, molasses, and final GM sugar product. The toxicity of GM sugar was examined with a feeding bioassay using Helicoverpa armigera larvae. PCR and RT-qPCR results showed that the leaves, stems, fibers, juices, syrups, filter mud, molasses, and white granulated sugar from GM sugarcane can be distinguished from those derived from non-GM sugarcane. The RT-qPCR detection method using short amplified product primers was more accurate than the traditional PCR method. Molecular analysis results indicated that trace amounts of DNA residues remain in GM sugar, and thus it can be accurately characterized using molecular analysis methods. ELISA results showed that only the leaves, stems, fibers, and juices sampled from the GM sugarcane differed from those derived from the non-GM sugarcane, indicating that filter mud, syrup, molasses, and white sugar did not contain detectable Cry1Ab and EPSPS proteins. Toxicity analysis showed that the GM sugar was not toxic to the H. armigera larvae. The final results showed that the GM sugar had no active proteins despite containing trace amounts of DNA residues. This finding will help to pave the way for the commercialization of GM sugarcane and production of GM sugar.

Keywords: PCR analysis; enzyme-linked immunosorbent assay; genetic modification sugar, genetic modification sugarcane; real-time fluorescent quantitative PCR; toxicity feeding bioassay.