Genome-Wide Characterization and Expression Analysis of CYP450 Genes in Chlamydomonas reinhardtii P.A. Dang.

Cytochrome P450 (CYP450) monooxygenases are a class of enzymes containing conserved heme-binding functional domain. They contribute to a wide range of biosynthetic processes, serving a pivotal function in plant resistance to abiotic stress. To date, little is known about the CYP450s of <i>Chlamydomonas reinhardtii</i>. In our study, a total of 37 <i>crP450</i> genes were identified from <i>C. reinhardtii</i> based on domain and sequence alignment, unevenly distributed on 12 chromosomes with 4 pairs of tandem replications shared among family members. Most of these genes contained 10 or more introns and encoded CYP450 proteins with an average of 593 amino acids and 3-9 conserved motifs. CYP450 enzymes were mainly distributed in the chloroplasts, cytoplasms, mitochondria, and cytoplasmic membranes. There were numerous light, jasmonic acid, abscisic acid, and salicylic acid response elements located in the upstream of gene coding sequences, suggesting that these genes could be modulated by plant hormones. Transcriptome analysis uncovered distinct expression patterns of <i>crP450</i> genes under various stress conditions, with the 37 <i>crP450</i> genes grouped into 9 clusters. In summary, this study presented a genome-wide characterization of <i>CYP450</i> genes in <i>C. reinhardtii</i>, providing a strong foundation for further exploration into their biological functions.