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Arabidopsis Thaliana Report

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Title
Occurrence of microRNA expressions using various nutrient deficiencies presented to Arabidopsis thaliana
Introduction
Arabidopsis thaliana is the model organism chosen for investigation of miRNA expression because its entire genome has been sequenced (Weems 362-369). This organism also has a short life cycle and grows relatively quick with restricted space and this also makes it useful for lab research (Weems 362-369). The nutrient concentrations that were observed in this study included phosphorus and sulfur. These nutrients are specifically used because they are considered macronutrients that are required for plant growth (Axtell). Phosphorus is a component of nucleic acids, phospholipids, ATP and coenzyme. Sulfur is also a component …show more content…

The plant recognizes the double stranded mRNA as foreign and breaks down the complex. This acts as a negative post-transcriptional control (Axtell). The four microRNAs used for this investigation were miR156, miR395, miR399 and miR398. The control, miR156, has no nutrient requirement and would be expected to show no change due to nutrient levels changing (Hsieh 2120-2132). miR399 is up-regulated during phosphate starvation and thus targets phosphorus uptake and metabolism (Hsieh 2120- 2132). miR398 is regulated when there is Copper/Zinc starvation, targeting the enzyme copper/zinc superoxide dismutase (Bouché 684– 686). This stress responsive miRNA has low levels of expression in both low sulfur and phosphorus environments (Bouché 684- 686). Lastly, miR395 depends on sulfur concentrations and targets mRNAs involved in sulfur metabolisms (Hsieh 2120-2132). These miRNAs should show different effects due to the nutrients …show more content…

The control in this experiment was the full media plate. The independent variable manipulated in this study was the media type that the seeds were grown on. The dependent variable measured was the varying levels of miRNA expression. I did a full media plate. The plates were then allowed to grow for two weeks. The full media plate was used in comparison to the low phosphorus and low sulfur plates. After growth the plants were collected with sterilized tweezers and grinded using a lysis mix and a pestle. Next, the kit used for isolating the small RNAs was a Sigma mirPremier microRNA isolation kit following the manufacturer’s protocol. The microRNAs were then run in the thermocycler performing reverse transcription reactions to convert the RNAs into single-stranded complementary DNAs. Reverse Transcriptase Master Mix was used for the reverse transcription reactions. Lastly, quantitative real-time polymerase chain reaction (qt-PCR) was used to analyze the microRNA levels. Four microRNAs were examined for each media type. Every media type was analyzed using this procedure and U6 was used as the reference gene for analysis. A U6 Master mix and miRNA master mix were used for analysis of each media type. The four primers used for analysis were miR156, miR395, miR398 and miR399. The efficiency values, E, were then obtained from the previous study (data

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