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Published on: January 14, 2016
Analysis of differential expression of Mediator subunit genes in Arabidopsis
Richa Pasrija1, Jitendra K Thakur
1National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India.
Abstract:
Mediator is a conserved eukaryotic multiprotein complex required by RNA polymerase II for transcription of its target genes. Till date, there is no report explaining the signals that affect the overall concentration of individual Med subunits. In this report, we have analyzed the effect of different phytohormones and stresses on the transcript level of Med genes in Arabidopsis. Hormones like auxin and JA, and cold stress did not show significant effect. ABA moderately increased the transcript abundance of more than 70% of AtMed genes analyzed in this study. However, there was noticeable change in the transcript level of several AtMed genes in response to BR. Stresses like high light, dark and salt also caused significant change in the transcript abundance of many AtMed genes. These data reveal that different environmental cues can affect stoichiometric concentration of Med subunits by affecting the transcription of their respective genes. This may, in turn, affect the overall arrangement of functional Mediator complex. This also suggests that some subunits may have some specific functions to play in response different signals.
Insights
Environmental signals like ABA, BR, and various stresses significantly alter the transcript levels of Mediator (Med) complex genes in Arabidopsis. This suggests environmental cues can impact Mediator subunit concentration and function.
Area of Science:
- Molecular Biology
- Plant Science
- Genetics
Background:
- The Mediator complex is crucial for RNA polymerase II transcription in eukaryotes.
- Little is known about factors influencing the abundance of individual Mediator subunits.
Purpose of the Study:
- To investigate the impact of phytohormones and environmental stresses on the transcript levels of Mediator (Med) genes in Arabidopsis.
- To understand how environmental signals modulate Mediator subunit stoichiometry.
Main Methods:
- Analysis of transcript levels of Arabidopsis Mediator (AtMed) genes.
- Exposure to various phytohormones (auxin, JA, ABA, BR) and environmental stresses (cold, high light, dark, salt).
Main Results:
- Auxin, JA, and cold stress had minimal effect on AtMed gene transcript levels.
- Abscisic acid (ABA) moderately increased the transcript abundance of over 70% of analyzed AtMed genes.
- Brassinosteroid (BR), high light, dark, and salt stress significantly altered the transcript levels of numerous AtMed genes.
Conclusions:
- Environmental cues, including phytohormones and stresses, can modulate the stoichiometric concentration of Mediator complex subunits by affecting their gene transcription.
- Changes in subunit levels may influence the overall structure and function of the Mediator complex.
- Specific Mediator subunits might play distinct roles in responding to different environmental signals.
