Microbial Symbiosis Research Paper

1445 Words 6 Pages
The definition of Symbiosis is "the living together in an intimate association of two or more dissimilar organisms". Symbiosis is a crucial part of our existence and a reason for the beginning of life on this planet we call home. According to history of our planet, Earth was formed from absolute nothingness to tiny molecules of thick water vapor and many compounds of nitrogen, carbon dioxide, ammonia, and more. From these molecules, the disorder and order of the molecule reacted with each other, creating and forming the first cell. Millions of years later, these cells created atmospheric oxygen. During the Great Oxidation event, many microbes obtain oxygen-reaction abilities, which overproduced atmospheric oxygen, trapping oxygen molecules …show more content…
This study uses plant-growth-promoting rhizobacteria to help plants tolerate abiotic stress. According the Yang et al. 2009, plant-growth-promoting rhizobacteria (PGPR) are being studied that may help the environment as well as utilize rhizobacteria to their maximum capacity. PGPR is an associated bacteria that colonizes and strengthens rhizosphere of plants. This bacteria directly increases nutrient uptake from the soil, reducing the overuse of fertilizers and accumulation of excess nitrates and phosphates in soil. Yang coined the term "Induced Systematic Tolerance" or IST to explain PGPR properties of physicals and chemical changes to aid in prevention of diseases and abiotic stresses. In their experiment, they tested out mixtures of PGPR strains with symbiotic nitrogen-fixing rhizobia or with mycorrhizal fungi in greenhouses and agriculture. In the first experiment, under drought stress, co-inoculation of the bean (Phaseolus vulgaris L.) and a rhizobium strain (Rhizobium tropici) and two strains of P. polymyxa resulted in enlargement of height and increased nodules.This makes sense because rhizobia's natural process, under stress and low soil-water content, is to drastically decrease nitrogen fixation. However, the overall effect of using two strains of P. polymyxa proved that the mixture of bacteria strains and rhizobium were perfect to exploit IST system and increase root nodules. Not only this, but I believe PGPR has the ability to change molecular DNA activities. I believe this because PGPR promotes root development and alter root architecture by the production of phytohormones like indole acetic acid (IAA). This production of hormones result in increased root surface area and numbers of root tips because of the push for nutrient uptake. We do not fully comprehend the mechanism, but

Related Documents