Date Palm (Phoenix dactylifera L.) Chloroplast Genome

Abstract

AbstractThe chloroplast is a significant organelle of autotrophic cells which contains an autonomous, double-stranded, circular DNA molecule (cpDNA) known as the chloroplast genome. It harbors crucial genes for maintenance of the chloroplast. The chloroplast genome encodes several components of the photosystems and enzymes involved in biosynthetic pathways. Understanding the molecular genetics of the chloroplast is important owing to its small size, conserved nature, determined gene organization and the favorable capability for transgenic expression. Hence, chloroplast genome sequences have been contributory in molecular phylogenetics and classification of plants. Chloroplast genome sequences of date palm (Phoenix dactylifera L.) were among the first crop organelle genomes reported. Date palm chloroplast genome sequences of four cultivars: Khalas from Saudi Arabia, Aseel from Pakistan, and Naghal and Khanezi from Oman are currently available. Similar to other flowering plants, the chloroplast genome of date palm is a double-stranded, circular DNA molecule exhibiting a quadripartite structure with a large and a small single-copy region (termed LSC and SSC, respectively) that are separated by two copies of inverted repeat regions (IR). With a size of ~ 158,000 bp, date palm cpDNA contains approximately 130 functional genes. Many single nucleotide variants (SNVs) as well as heteroplasmy, more than one type of organellar genome within an individual, have been observed in the date palm chloroplast genome. Chloroplast genome sequences from date palm cultivars have improved our insights into chloroplast biology, conservation, diversity and intracellular gene transfer.KeywordscpDNAChloroplast genomeDate palmOrganelle genome Phoenix dactylifera