Tomato COI gene family identification and expression under abiotic and phytohormone stress

The CORONATINE INSENSITIVE (COI) plays pivotal roles in plant growth and development, including pollen fertility, defence against pests, trichome formation, and seed germination. In this study, we performed bioinformatics characterization of COI proteins in tomato and analysed their expression profile analysis under abiotic stress. A total of nine members of the COI gene family were isolated and phylogenetically clustered into five distinct clades with Arabidopsis, rice, maize, and other related plant species. Subcellular localization showed selected COI proteins predominantly localized in the nucleus. The reverse transcription quantitative real-time polymerase chain reaction analysis revealed distinct spatial expression patterns SlCOIs among different tissues mainly found in the root and fruits of different developmental stages. In addition, we examined different hormone and abiotic stresses related to cis-regulatory sequences in upstream regions of these genes. Further, we examined differential changes in SlCOIs transcripts accumulation in response to different hormones (ABA, IAA, GA, SA and MeJA), salinity, drought, and cold. It was found that SlCOI1, SlCOI2, SlCOI3, SlCOI4, SlCOI5 and SlCOI7 was peaked under ABA, GA, SA and MeJA while, SlCOI1, SlCOI3, SlCOI6 and SlCOI8 were upregulated under salt, drought, and cold. These results provide invaluable insights into functional and protein functional features. Our research also provides a foundation for further functional characterization of COI genes in tomato.