Philosophical Reflection on Risks of Transgenic Technology

[Objective] The aim was to analyze risks of transgenic technology. [Method] Discussions on risks of transgenic technologies were conducted from perspective of philosophy. [Result] Mechanistic philosophy and reductionism are causes of reflection on risks of transgenic technology. Considering transgene is an artificial choice taking place of natural choice, it is inevitable for risks of transgenic technology to be found. In addition, social system constitutes the root for out-of-control of transgenic technology, hence, mechanism risk is the primary cause of transgenic risks. [Conclusion] It is inescapable for science view to be changed from arbitrary and lopsided to reflective and comprehensive and for technology view to be changed from exterminative and genesic to protective and symbiotic.

Advances in Alfalfa Transgenic Technology and Its Application

This paper summarized the research advances of several commonly used alfalfa transformation technologies including Agrobacterium-mediated transforma- tion method, electroperation method, microinjection method and biolistic method, and introduced the latest research findings in genetic improvement of alfalfa using transformation technologies to improve the quality and increase the resistance against diseases, insects and herbicides, as well as in production of plant-based vac- cines, enzyme preparations and antibodies using transgenic alfalfa as biological reactors. In addition, the current bottleneck constraining the development of alfalfa transformation technologies and related biesafety issues were analyzed and discussed, and the application prospects and commercial value of transgenic alfalfa were p^opes~.

Molecular cloning and functional analysis of the pepper resistance gene Me3 to root-knot nematode

Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)markers and insertion/deletion(In Del)markers were developed to fine map the Me3 gene.Analysis of 2272 individuals(F2progenies)revealed that Me3 was located in a 45-kb DNA region between markers SSR784 and SSR339,in which there were three candidate genes.Among them,as a novel nucleotide binding site and leucine rich repeat(NBS-LRR)family gene,the DNA sequence of Capana09g000163 of pepper line‘HDA149’was 6348 bp in length,with a 2802-bp open reading frame encoding 933 amino acids,including NB-ARC and LRR domains.Tobacco transient expression assays demonstrated that expression of Capana09g000163 triggered a hypersensitive response(HR)in Nicotiana benthamiana leaves.Subcellular localization results showed that the Capana09g000163 protein was localized in the cell nucleus.Ectopic expression of Capana09g000163 in Arabidopsis significantly increased resistance against Meloidogyne incognita compared with the wild-type(WT)Arabidopsis.Furthermore,M.incognita was almost unable to develop in transgenic Arabidopsis expressing Capana09g000163.Taken together,we cloned the Me3 gene and verified that it induced resistance against M.incognita with the methods of map-based cloning and transgenic technology,which may be of great significance to pepper breeding for resistance against RKNs.

Advances in Studies of Genetic Improvement of Sugarcane

Sugarcane(Saccharum spp.) is a large perennial herbaceous plant that is cultivated in tropical and subtropical regions of the world,and it is also one of the most efficient crops in the world in converting energy from sunlight into chemical energy. As an essential sugar crop and energy crop,sugarcane is receiving an increasing concern for its variety improvement. Traditional breeding and cultivation techniques have contributed a lot to increasing sugarcane yield and sucrose content. In recent years,development and application of biotechnology provide much help for genetic improvement of sugarcane. For convenience of breeders fully knowing advances in studies of sugarcane genetic improvement,this paper elaborated conventional breeding,genomics,GM technology,and molecular marker assisted breeding.

An efficient and safe strategy for germ cell-specific automatic excision of foreign DNA in F1 hybrid transgenic silkworms

The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic eggs.To address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic silkworms.We established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression cassette.The FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic silkworms.This strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.

Synthetic biology of plant natural products: From pathway elucidation to engineered biosynthesis in plant cells

Plant natural products(PNPs)are the main sources of drugs,food additives,and new biofuels and have become a hotspot in synthetic biology.In the past two decades,the engineered biosynthesis of many PNPs has been achieved through the construction of microbial cell factories.Alongside the rapid development of plant physiology,genetics,and plant genetic modification techniques,hosts have now expanded from single-celled microbes to complex plant systems.Plant synthetic biology is an emerging field that combines engineering principles with plant biology.In this review,we introduce recent advances in the biosynthetic pathway elucidation of PNPs and summarize the progress of engineered PNP biosynthesis in plant cells.Furthermore,a future vision of plant synthetic biology is proposed.Although we are still a long way from overcoming all the bottlenecks in plant synthetic biology,the ascent of this field is expected to provide a huge opportunity for future agriculture and industry.