Recombinant proteins provide new means for disease treatment, while creating considerable economic benefits. Using commercial crops (mainly tobacco), cereal crops, legumes, and vegetable crops to produce recombinant proteins with medicinal value is a hot-spot for research in "molecular farming". Although many recombinant proteins have been expressed in plants, only a small number have been successfully put into use. To overcome the problems that greatly hamper the development of recombinant protein production in plants, researchers have improved expression systems to increase the yield of recombinant proteins. Starting from analyzing the problems of low yield and/or low biological activity of recombinant proteins produced by plants, the optimization strategies to solve these problems were reviewed, and future research directions for improving the yield of recombinant proteins produced by plants were proposed.
Crops, Agricultural/genetics* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics* ; Recombinant Proteins ; Tobacco/genetics*

Plants provide an immense reservoir of natural secondary metabolites. Secondary metabolites and those involved enzymes accumulate in various compartments in specific plant tissues. The biosynthesis of diverse groups of secondary metabolites is often complicated, tightly controlled via network interconnections, metabolite levels, metabolite channeling and multi-enzyme complexes, and so on. Secondary metabolite profiles could be genetically altered by two strategies, i.e. single gene modification and multiple gene modification; which thus has opened a feasible and prospective platform for secondary chemicals production in plant.
Gene Expression Regulation, Plant ; Phytochemicals ; biosynthesis ; genetics ; Plants ; genetics ; metabolism ; Plants, Genetically Modified ; genetics ; metabolism ; Secondary Metabolism ; genetics ; Transformation, Genetic

Using plants to remove or inactivate heavy metal pollutants from soils and surface waters provide a cheap and sustainable approach of Phytoremediation. However, field trials suggested that the efficiency of contaminant removal using natural hyperaccumulators is insufficient, due to that many of these species are slow growing and produce little shoot biomass. These factors severely constrain their potential for large-scale decontamination of polluted soils. Moreover, both the micronutrient and toxic metal content accumulated in crops determine the quality and safety of our food-chain. By a transgenic approach, the introduction of novel genes responsible for hyperaccumulating phenotype into high biomass plants and/or stable crops uptaking minerals as food is a promising strategy for the development of effective techniques of phytoremediation and improvement of nutritional value of stable food through a viable commercialization. Recently, the progress at molecular level for heavy metal uptaking, detoxification and hyperaccumulation in plants, and also the clarification of some functional genes in bacteria, yeasts, plants and animals, have advanced the research on genetic engineering plants of heavy metal resistance and accumulation, and on the functional genes (e . g. gsh1, MerA and ArsC) and their genetic transformated plants. These studies demonstrated commercialization potentials of phytoremediation. In this paper, the molecular approach, effects and problems in gene transformation were discussed in details, and also the strategy and emphases were probed into the future research.
Biodegradation, Environmental ; Genetic Engineering ; methods ; Metals, Heavy ; metabolism ; Plants, Genetically Modified ; genetics ; metabolism ; Soil Pollutants ; metabolism

Resveratrol synthase (RS) plays a key role in resveratrol (Res) biosynthesis. RS gene has been formerly reported to be transformed into many plant species and microorganisms, and to play certain roles in metabolic and regulation processes. In this paper, the transformations of RS gene in plants, and the related changes of biological properties, such as metabolites, anti-pathogen activities, anti-radical properties, and developmental characters in transgenic plants, as well as the production of resveratrol in microbes by utilizing RS gene were summarized. Moreover, the application prospects of RS gene in bioengineering were also addressed.
Acyltransferases ; genetics ; Genetic Engineering ; Plants, Genetically Modified ; enzymology ; genetics ; Stilbenes ; metabolism

Cucumber (Cucumis sativus) is an important vegetable crop in the world. Agrobacterium-mediated transgenic technology is an important way to study plant gene functions and improve varieties. In order to further accelerate the transgenic research and breeding process of cucumber, we described the progress and problems of Agrobacterium tumefaciens-mediated transgenic cucumber, from the influencing factors of cucumber regeneration ability, genetic transformation conditions and various additives in the process. We prospected for improving the genetic transformation efficiency and safety selection markers of cucumber, and hoped to provide reference for the research of cucumber resistance breeding and quality improvement.
Agrobacterium tumefaciens ; metabolism ; Breeding ; Cucumis sativus ; genetics ; microbiology ; Plants, Genetically Modified ; microbiology ; Research ; Transformation, Genetic

Plant can be used as bioreactor for heterogenous protein expression. We reviewed different expression systems of plant bioreactor as well as recent relevant developments. In addition, we discussed perspectives in combination with our own experience.
Bioreactors ; microbiology ; Biotechnology ; trends ; Plants ; genetics ; metabolism ; Plants, Genetically Modified ; metabolism ; Protein Engineering ; methods ; Recombinant Proteins ; biosynthesis ; genetics

The expression of plant gene is controlled by its promoter. The isolation and the function analysis of promoter are important for studying the genetic engineering and the regulation expression of plant genes. In this paper, we cloned a promoter, 0s252, which was predicted to be highly expressed in the stem of rice from the EST database. After the construction of the Os252::GUS expression vector, it was transformed into rice. The integration of transgenes into transgenic rice genome was confirmed through PCR analysis. X-Gluc staining showed that Os252 can promote GUS gene expression in leaf, stem and matured seed. GUS enzyme activities driven by Os252 promoter in leaf and seed are about 190% and 250% of that driven by the 35S promoter. Thus, the Os252 promoter can be applied for rice genetic engineering.
Gene Expression Regulation, Plant ; Oryza ; genetics ; metabolism ; Plant Proteins ; genetics ; Plants, Genetically Modified ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics

OBJECTIVETo investigate the biotransformation of daphnetin by suspension transgenic hairy root of Polygonum multiflorum and provide a biotechnological method for large-scale production of the daphnetin-8-O-beta-D-glucoside using this new culture system.

METHODDaphnetin was added into the media of suspension to culture 36 h. The biotransformation product was detected with TLC and HPLC, and isolated by various chromatographic methods. The influence of co-cultured time on conversion ratio, content of degradation product and the reason for the degradation of product II were investigated using HPLC.

RESULTOne biotransformation product, daphnetin-8-O-beta-D-glucoside, was obtained, the optimal co-cultured time in suspension hairy root of P. multiflorum was 36 h with the highest biotransformation molar ratio of 32.11%, the sucrose medium (sucrose-only) can increase the biotransformation molar ratio to 72.44%. The result demonstrated that the degradation products of the product II was induced by the MS medium.

CONCLUSIONThe potential application of suspension transgenic hairy root of P. multflorum in the sucrose-only medium on generating daphnetin-8-Obeta-D- glucoside could be prospective.

Biotransformation ; Coculture Techniques ; Glucosides ; metabolism ; Plant Roots ; genetics ; metabolism ; Plants, Genetically Modified ; Polygonum ; genetics ; metabolism ; Umbelliferones ; metabolism

ACC oxidase (ACO) is one of the key enzymes that catalyze the synthesis of ethylene. Ethylene is involved in salt stress response in plants, and salt stress seriously affects the yield of peanut. In this study, AhACO genes were cloned and their functions were investigated with the aim to explore the biological function of AhACOs in salt stress response, and to provide genetic resources for the breeding of salt-tolerant varieties of peanut. AhACO1 and AhACO2 were amplified from the cDNA of salt-tolerant peanut mutant M29, respectively, and cloned into the plant expression vector pCAMBIA super1300. The recombinant plasmid was transformed into Huayu22 by pollen tube injection mediated by Agrobacterium tumefaciens. After harvest, the small slice cotyledon was separated from the kernel, and the positive seeds were screened by PCR. The expression of AhACO genes was analyzed by qRT-PCR, and the ethylene release was detected by capillary column gas chromatography. Transgenic seeds were sowed and then irrigated with NaCl solution, and the phenotypic changes of 21-day-seedings were recorded. The results showed that the growth of transgenic plants were better than that of the control group Huayu 22 upon salt stress, and the relative content of chlorophyll SPAD value and net photosynthetic rate (Pn) of transgenic peanuts were higher than those of the control group. In addition, the ethylene production of AhACO1 and AhACO2 transgenic plants were 2.79 and 1.87 times higher than that of control peanut, respectively. These results showed that AhACO1 and AhACO2 could significantly improve the salt stress tolerance of transgenic peanut.
Salt Tolerance/genetics* ; Arachis/genetics* ; Plant Breeding ; Ethylenes/metabolism* ; Plants, Genetically Modified/genetics* ; Gene Expression Regulation, Plant ; Plant Proteins/genetics*

To explore the function of a heat shock transcription factor gene (HSFB1) and its promoter in Amorphophallus, a 1 365 bp DNA sequence was obtained by homologous cloning from Amorphophallus albus. The gene expression level of AaHSFB1 determined by qRT-PCR indicated that AaHSFB1 gene is more sensitive to heat stress. The expression level of AaHSFB1 in roots increased followed by a decrease upon heat treatment, and the highest expression level was observed after heat treatment for 1 h. The expression level of AaHSFB1 in leaves reached the highest after heat treatment for 12 h. The expression level in bulbs did not change greatly during the heat treatment. Subcellular localization analysis showed that AaHSFB1 protein was localized in the nucleus. A 1 509 bp DNA sequence which contains the AaHSFB1 promoter was obtained by FPNI-PCR method. Bioinformatics analysis showed that the promoter contained heat stress response elements HSE and a plurality of cis-acting elements related to plant development and stress response. A prAaHSFB1::GUS fusion expression vector was constructed to further analyze the function of AaHSFB1 promoter. The expression vector was transformed into Arabidopsis thaliana by Agrobacterium tumefaciens-mediated method, and GUS staining analysis on transgenic plants after heat treatment was performed. The results showed that AaHSFB1 promoter had very high activity in the leaves. Therefore, we speculate that AaHSFB1 may play an important role in the stress resistance of A. albus, especially when encountering heat stress.
Amorphophallus/metabolism* ; Arabidopsis/genetics* ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics*