Ribonucleic acid synthesis by chromatin isolated from Phaseolus aureus Roxb. : The effect of endogenous ribonuclease

Area of Science:

• Molecular Biology
• Plant Biochemistry

Background:

• Endogenous RNA polymerase activity in plant chromatin is crucial for gene expression.
• Investigating RNA polymerase activity in Phaseolus aureus Roxb. hypocotyls is essential for understanding plant development.

Purpose of the Study:

• To characterize the in vitro RNA polymerase activity in Phaseolus aureus Roxb. chromatin.
• To identify factors affecting the molecular weight of RNA synthesized by endogenous RNA polymerase.

Main Methods:

• Chromatin isolation from Phaseolus aureus Roxb. hypocotyls.
• In vitro RNA polymerase assay and polyacrylamide gel electrophoresis for RNA product analysis.
• Sensitive enzyme assays to detect ribonuclease activity.

Main Results:

• Synthesized RNA products were smaller than in vivo synthesized RNA and sensitive to assay temperature.
• Ribonuclease activity, though not detected by conventional assays, was present and degraded high-molecular-weight RNA.
• Inclusion of exogenous RNA increased the molecular weight of in vitro synthesized RNA products.

Conclusions:

• Ribonuclease activity significantly impacts the size of RNA synthesized by endogenous RNA polymerase in vitro.
• Exogenous RNA can mitigate ribonuclease degradation, leading to higher molecular weight RNA products.
• Optimizing chromatin preparation and assay conditions is crucial for studying RNA polymerase activity in vitro.