This is the first evidence that replicating vectors can be successfully used for transient protein expression in BY-2 plant cell packs. Transient recombinant protein expression in plants and recently also plant cell cultures are of increasing interest due to the speed, safety and scalability of the process. Currently, studies are focussing on the design of plant virus-derived vectors to achieve higher amounts of transiently expressed proteins in these systems. Here we designed and tested replicating single and multi-cassette vectors that combine elements for enhanced replication and hypertranslation, and assessed their ability to express and particularly co-express proteins by Agrobacterium-mediated transient expression in tobacco BY-2 plant cell packs. Substantial yields of green and red fluorescent proteins of up to ~ 700 ng/g fresh mass were detected in the plant cells along with position-dependent expression. This is the first evidence of the ability of replicating vectors to transiently express proteins in BY-2 plant cell packs.

• Keywords
• DsRed, GFP, Plant cell pack, Plant expression vector, Tobacco BY-2 cells, Transient co-expression,
• MeSH
• Agrobacterium genetics   MeSH
• Cell Culture Techniques MeSH
• Red Fluorescent Protein MeSH
• Genetic Vectors * MeSH
• Plants, Genetically Modified genetics   MeSH
• Luminescent Proteins genetics   MeSH
• Protein Engineering methods   MeSH
• Recombinant Proteins genetics   metabolism   MeSH
• Replicon MeSH
• Plant Cells metabolism   MeSH
• Nicotiana cytology   genetics   MeSH
• Green Fluorescent Proteins MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Luminescent Proteins MeSH
• Recombinant Proteins MeSH
• Green Fluorescent Proteins MeSH

BACKGROUND: The use of light emitting diodes (LEDs) brings several key advantages over existing illumination technologies for indoor plant cultivation. Among these are that LEDs have predicted lifetimes from 50-100.000 hours without significant drops in efficiency and energy consumption is much lower compared to traditional fluorescent tubes. Recent advances allow LEDs to be used with customized wavelengths for plant growth. However, most of these LED growth systems use mixtures of chips emitting in several narrow wavelengths and frequently they are not compatible with existing infrastructures. This study tested the growth of five different plant species under phosphor coated LED-chips fitted into a tube with a standard G13 base that provide continuous visible light illumination with enhanced blue and red light. RESULTS: The LED system was characterized and compared with standard fluorescence tubes in the same cultivation room. Significant differences in heat generation between LEDs and fluorescent tubes were clearly demonstrated. Also, LED lights allowed for better control and stability of preset conditions. Physiological properties such as growth characteristics, biomass, and chlorophyll content were measured and the responses to pathogen assessed for five plant species (both the model plants Arabidopsis thaliana, Nicotiana bentamiana and crop species potato, oilseed rape and soybean) under the different illumination sources. CONCLUSIONS: We showed that polychromatic LEDs provide light of sufficient quality and intensity for plant growth using less than 40% of the electricity required by the standard fluorescent lighting under test. The tested type of LED installation provides a simple upgrade pathway for existing infrastructure for indoor plant growth. Interestingly, individual plant species responded differently to the LED lights so it would be reasonable to test their utility to any particular application.

• Keywords
• Arabidopsis thaliana, Fluorescent tubes, LED, Light, Nicotiana bentamiana, Oilseed rape, Plant physiology, Potato, Soybean,
• Publication type
• Journal Article MeSH