Handling Biotechnology: Plants do also have stress, it is releaved by its tiny friend !! Guess who it is ?!

We always say " Look deep into the nature, and then you will understand everything better". Nature is more responsive for us to live peacefully. That gives us happiness whenever we look at the nature.

Plants are the most cheerful organisms that cherishes the Nature.

Plants are always smarter, you know !!! Its pretty cool, they eat sunlight and leaves out the fresh air. But when it comes to extreme environmental conditions such as drought, salinity, and freezing temperature there is adverse effect on the growth and the productivity of crop plants.

The temperature ( heat, chilling, freezing) drought and salinity stress together represent Abiotic stress. Due to increase in population, there is more demand for food and hence agricultural practise must feed more people. This increasing demand must combat with new strategies that are to be enforced to enhance crop productivity.

One feasible way to combat with stress problem is to develop crops that are more tolerant to abiotic stresses, so that the new land can be brought under cultivation. Although traditional breeding method provides marginal relief, genetic engineering offers fastest and effective strategy for dealing stresses problem particularly in enhancing plant tolerance to stress.

In nature several organisms have evolved resistant traits that enable them to survive in extreme environment. Several microorganisms have been used as a model system to characterize stress induced genes. Generally, when plants or microorganisms are continuously exposed to extreme environmental conditions , their stress relieving genes that are transcribed might encode enzymes involved in regulating particular metabolic pathways or proteins with specific functions. Response to abiotic stresses enable the organisms to adapt to an unfavorable condition singly by altering the metabolic way.

Considering stress factors, drought and salinity are the most significant issues threatening agricultural production on a global scale. It is estimated that total economic value of loss caused by drought and heat globally is 1.3 billion and due to cold is about 18.6 billion. This has enhanced the scientific manpower to evolve transgenic strategy to enhance plant productivity.

Ice nucleating bacteria

Formation of ice on the plant cells ( outer membrane ) is a complex chemical process. The importance of ice nucleating bacteria is recognized in recent years. The occurrance of these bacteria has been reported in most part of the plants- Cereals, fruits and vegetable crops. The ice-nucleating bacteria synthesize proteins, which coalesce with water molecules to form ice crystals at temperature around 32° F. As the ice crystals grow, they can pierce the plant cells and severely damage the plants.

Plants can be treated with copper compounds to kill the bacteria. Another approach is to use urea solution so that the ice formation is minimized.

Ice Minus Bacteria

The bacterium Pseudomonas syringae is one of the highly prevalent ice-forming organisms in nature. With genetic manipulations, the gene that directs the synthesis of ice- related bacterial proteins in P.syringae was removed. These newly developed bacteria are reffered to as ice-minus bacteria.

It was in 1987, ice minus bacteria were sprayed on to the field of potato plants and strawberry plants. Another strain of P.syringae commercially labelled as Frostban was later developed and used in crop fields.

It may be noted here ice-minus bacteria of P.syringae was the first transgenic bacteria that were used outside the laboratory. Fortunately, the experiments yielded encouraging results, since crop damage due to the frost formation was found to be reduced.

Arabidopsis with cold tolerant genes

Scientists were successful in developing cold-tolerant genes ( around 20) in Arabidopsis when these plants were gradually exposed to slowly declining temperatures.They are also identified a coordinating gene that encodes a protein, which acts as a transcription factor for regulating the expression of cold-tolerant genes. By introducing the coordinating gene, expression of cold-tolerant genes was triggered, and this protected the plants against cold temperature. More work is in progress in this direction.