PATTERNS OF CODON USAGE BIAS IN CARBONIC ANHYDRASE REVEAL ADAPTIVE EVOLUTION IN C3 AND C4 PHOTOSYNTHETIC PATHWAYS

Abstract

Photosynthesis is an essential biological process that supports life on Earth by transforming carbon dioxide and water into glucose and oxygen while this process involves complex biochemical pathways. Carbonic anhydrase (CA) is a crucial enzyme in this process that convert carbon dioxide and water into bicarbonate and protons thus ensures an adequate CO₂ supply to the Calvin cycle. This study represents the nucleotide composition of CA gene in C3 and C4 plants to understand codon usage patterns at different positions within the genes. Computational analyses such as codon adaptation index (CAI) and relative synonymous codon usage (RSCU) were used to analyze codon usage bias. Correspondence Analysis (COA) was utilized to explore synonymous codon usage variance that reveals evolutionary trends and genetic linkages among the plant species. Neutrality Plot Mapping and Effective Number of Codons (ENC) analysis were conducted to check the impact of natural selection and mutational pressure on codon usage. The study highlights the relations between GC contents and codon bias that offers the insights into the expression and adaptability of CA enzymes across different plant species and their evolutionary relationships.This study offers valuable overview of the complex forces driving codon usage patterns in the carbonic anhydrase gene across various plants. The findings suggest that both random genetic changes and natural selection, particularly favoring specific codon terminations, contribute to the observed codon bias.