Unique Loss of Photosynthetic Functions and Unusually Low GC Content in the Minimized Plastids found in Holoparasitic Plants

The reduction of holoparasitic plants’ plastomes is an intriguing phenomenon that we sought to explore via bioinformatic analysis of various DNA sequences. Our research supports that holoparasitic plants have a trend of unusually low proportions of GC content in their chloroplast genes compared to hemiparasitic and autotrophic plants. Plastid genes essential for sustaining life such as tRNA synthesis were present in each species of holoparasitic plant, whereas those related to photosynthesis were present in only a few species. We calculated dN/dS ratios of certain protein-coding genes with high mutation pressure that favored for holoparasitism which is vital for its functionality.