Genome-wide identification, characterization, and expression analysis of tea plant autophagy-related genes (CsARGs) reveals diverse roles during development and abiotic stress

Background Autophagy, meaning ‘self-eating’, is required for degradation and recycling of cytoplasmic constituents under stressful or non-stressful conditions, thereby contributing to maintaining cellular homeostasis, delaying aged and longevity in eukaryotes. So far, the functions of autophagy have been intensively studied in yeast, mammals and model plants, but few studies have focused on economic crops, especially for tea plants, the roles of autophagy in coping with different environment stimuluses have not yet been detailed. Therefore, exploring the functions of autophagy related genes in tea plant would contribute to further understanding the mechanism of autophagy in response to stresses in woody plants. Results Here, we totally identified 35 CsARGs in tea plant. Each CsARG is highly conserved with its homologues stemmed from other plant species, except for CsATG14. Tissue-specific expression analysis revealed that the abundances of CsARGs were varied with different tissues, but CsATG8c/i showed a certain degree of tissue specificity, respectively. Under hormones and abiotic stress conditions, most of CsARGs were up-regulated at different treatment time points. In addition, the transcriptions of 10 CsARGs were higher in cold-resistance cultivar ‘Longjing43’ than the cold-susceptible cultivar ‘Damianbai’ during CA periods, however, CsATG101 showed a contrary tendency. Conclusions We comprehensively analyzed the bioinformatics and physiological roles of CsARGs in tea plant, and these results provide the basis for deepen exploring the molecular mechanism of autophagy involved in tea plant growth and development and stress responses. Meanwhile, some CsARGs would be served as putative molecular markers for cold-resistance breeding of tea plant in future.