Impact of transgenic insect-resistant maize HGK60 with Cry1Ah gene on community components and biodiversity of arthropods in the fields

1. Introduction With the ever-growing human population, food security is the major concern of this century [1]. Thus, obtaining higher crop yield per capita through various sustainable approaches has become more and more important. Genetically modified (GM) crops, which are the introduc- tion of beneficial genes in a crop plant, can provide sustainable agronomic and economic ben- efits [2]. GM crops have been commercialized for 26 years, and some of them such as insect resistant, herbicide resistant, combined insect and herbicide resistant and viral disease resis- tant crops are being cultivated in different parts of the world [3,4]. The planting area of GM crops was 190.4 million hectares, an increase of 112 times over 1996, 2.7 billion hectares repre- sents the total planting area from 1996 to 2019 [5]. Great progress has also been made in the research and development of GM crops in China. Transgenic cotton, poplar, sweet pepper, papaya and other crops have been released in the environment for many years, and transgenic insect-resistant rice, phytase transgenic maize and other crops also have the technical capacity of commercial production. Although global commercialization of GM crops has rapidly increased in the past 26 years, the safety of GM crops is still the most important factor restrict- ing the further development of industry. The safety issues of GM crops mainly include food safety and environmental safety [6]. In order to solve the safety issues, the international organi- zations and some countries have made great efforts to improve the safety of GM organisms.

There are promulgated laws and regulations on the safety management of GM organisms [7– 10], which require that the research and development of GM organisms must be evaluated in advance on food safety and environmental safety. Although the safety evaluation can be used for commercial production and application, safety management measures including environ- mental monitoring should be taken in the process of production and application. In the exist- ing environmental monitoring process, some agricultural concerns associated with commercial cultivation of GM crops have been reported [11]. In Bt crops for example, the tar- get insect pests may develop Bt toxin resistance over time, making them more difficult to be controled in the future [12,13]. The fear is that the transgene flow from Bt crops to surround- ing plant diversity, and the potential development of ‘super weed’ is one of the examples [14]. Maize is one of the most widely planted crops in the world, and insect pests are the main factors affecting its quality and yield. Compared with traditional maize, transgenic insect resis- tant maize can effectively reduce the number of target pests, reduce the occurrence of insect pests in the fields, reduce the dependence on chemical insecticides, and also slow down the impact of insecticides on the environment. Will it affect the biodiversity of arthropods in the fields? That still needs comprehensive safety measurement, which is also an important part of the environmental safety assessment of GM crops.

Arthropod communities are an important part of natural ecosystems and are important fac- tors in maintaining the normal ecological functions of farmland ecosystem [15]. Arthropod communities promote the exchange of substance and energy in soil ecosystem through decomposing biological residues, changing soil physical-chemical properties and maintaining soil moisture and temperature [16,17]. Studying insects and natural predatory communities has an important guiding role in the practice of farmland pest control. In addition, the diver- sity of arthropod communities (including insects) reflects the relationship between organisms and the environment. Therefore, the diversity of arthropods in the field is an important com- ponent of the environmental safety assessment of GM crops. Insect-resistant gene Cry1Ah is environmental safe product thanks to its higher toxic to a variety of lepidopterous insects and low toxicity to economic insects such as Bombyx mori. But, the expression of Cry1Ah might lead to alter plant root metabolites composition to induce changes in ambient soil biodiversity [18]. El-Wakeil and Volkmar [19] thought the Bt- PLOS ONE Impact of transgenic insect-resistant maize HGK60 with Cry1Ah gene PLOS ONE | https://doi.org/10.1371/journal.pone.0269459 June 3, 2022 2 / 13 Competing interests: The authors have declared that no competing interests exist