Environmental light induce deletion-dependent RNA editing in the mitochondrial atp6 gene of Calotropis procera

Abstract

Evidence substantiates a correlation between RNA editing and cellular stress in plants, particularly within organelles such as mitochondria responsible for electron transport. The mitochondrial atp6 (mt-atp6) gene, which is renowned for playing a crucial role in ATP synthase activity, encodes the a-subunit of ATP synthase. We conducted a comprehensive analysis encompassing three distinct environmental conditions (dawn, midday, and pre-dusk): pre- and post-irrigation intervals, assessing cDNAs derived from the mt-atp6 gene (accession no. OQ673859) in the arid plant species Calotropis procera. Reconstructed atp6 cDNAs corresponding to dawn (accession no. OQ673860), midday (accession no. OQ673861), and pre-dusk (accession no. OQ673862) were generated from RNA-seq data. Conversely, cDNA assemblies’ post-irrigation yielded iD (accession no. OQ673863), iM (accession no. OQ673864), and iPD (accession no. OQ673865) transcripts. Furthermore, Atp6 DNA sequences were reconstituted utilizing the MT-atp6 gene from Hoya lithophytica (accession no. MW71905). Our research showed that the mt-atp6 gene of Calotropis procera has 19 editing sites. Eleven of these sites stayed the same in all of the conditions we tested them in. Finding fragment deletions was an interesting discovery. This was a new phenomenon that was seen in all conditions except for the pre-dusk (PD) and post-irrigation pre-dusk (iPD) datasets. It was discovered that deletions that depend on editing RNA had a big effect on the secondary and tertiary structures of the ATP synthase alpha-subunit, which in turn had an effect on the accumulation of ATP. Among these sites, three were specific to the dawn and midday conditions before (D, M) and after irrigation (iD, iM), three were specific to the pre-dusk conditions before (PD) and after irrigation (iPD), and two sites were exclusive to the post-irrigation pre-dusk (iPD) dataset.