Transient expression of a green fluorescent protein in tobacco and maize chloroplast

Maize is considered to be one of the staple crops across the world. However, the limited production and unforeseen weather conditions often limit its availability. This is the major reason that scientists across the globe are working towards finding ways to improve the stability of the maize crop in harsh environmental conditions and its overall production rate. The improved quality of maize will not only help meet the demand of the ever-growing global population but will also overcome the shortage due to unanticipated environmental conditions. To achieve this, researchers tried for maize plastid transformation, which is not achieved effectively yet due to the recalcitrant conditions of the crop.

In the present study, researchers constructed two vectors containing homologous recombination sequences from maize and grass. These vectors are designed to later integrate into the chloroplast genome from an inverted repeat region. The vectors consist of two crucial genes mgfp5 and hph gene (as selection marker). The former gene is driven by Prrn, a leader sequence of the atpB gene and a terminator sequence from the rbcL gene. Whereas the later is driven by Prrn, a leader sequence from rbcL gene and a terminator sequence from the rbcL gene. The vectors were then used to transform the explants of maize, tobacco, and E.coli to assess the transitory expression. The expression levels were evident from the green and red fluorescent light when observed under the epiflourescence microscope.

The results of the study show the successful expression of both vectors, along with the presence of a reporter gene in all three organisms. This highlights the capability of vectors to express genes in the cell compartments. The results in the paper are the first report of transient expression of GFP in maize embryos, offering the opportunity to improve the recalcitrant crops genetically using biotechnological interventions. 

An in situ-Synthesized Gene Chip for the Detection of Food-Borne Pathogens on Fresh-Cut Cantaloupe and Lettuce

Food-borne pathogens are one of the major reasons behind endangering the life and safety of people across the globe. Fresh foods are specifically more vulnerable to these pathogens, making it crucial to have a very efficient food safety surveillance technology. The development of such technology will help in offering rapid detection of food-borne pathogens. In the present study, researchers developed an In-situ synthesized gene chip for the detection of the food-borne pathogen. Here the researchers first identified and screened the target genes by comparing the sequences of common food-borne pathogens like Salmonella, Vibrio parahemolyticus, Staphylococcus Aureus, Listeria monocytogenes and E.coli 0157:H7 from the NCBI database. Unique tilling array probes were designed that helps to target the selected genes in an optimized hybridization system. The resultant assay showed high specificity along with strong amplification signals. The results were highly accurate with a detection limit of approximately 3 log cfu/g without culturing. The detection time for the five target food-borne pathogens on the fresh-cut cantaloupe and lettuces was found to be 24 hours. This highlights the great efficacy of the detection system to rapidly monitor the pathogens on the fresh food items. Such a system can be easily incorporated as an efficient food surveillance system for checking the logistical distribution chain, the food at the processing stage, cleaning condition at the food manufacturing plants, transport, sales and more. The technology is considered valuable as it supports the safety of fresh agricultural products, reducing the overall wastage of food due to infectious pathogens.