Cloning and Expression Analysis of ATG8 (Autophagy-Related 8) Gene Family in Solanaceae

The autophagy-related gene family <i>ATG8</i> (Autophagy-related 8) plays an important role in plant growth, development, and stress response. In this study, 15 <i>ATG8</i> gene family sequences were amplified from Solanaceae, namely tobacco, tomato, and pepper, using RT-PCR to evaluate their basic properties, protein structure, and function, as well as the role of <i>ATG8</i> in autophagy. The physicochemical properties, the predicted secondary and tertiary protein structures, subcellular localisation, gene structures, conserved motifs, and phylogenetic relationships of the <i>ATG8</i> genes were analysed using bioinformatic techniques, and their expression patterns under sericin-induced plant disease resistance were investigated by RT-qPCR. The lengths of these proteins ranged from 79 to 120 aa, while their predicted molecular weights and isoelectric points (<i>PI</i>) ranged from 9283.62 to 13,778.74 and 6.32 to 11.44, respectively. The majority of the proteins were localised in the nucleus or chloroplasts. Conserved protein motifs and various cis-regulatory elements in the protein, with a wide range of related functions, were identified. The <i>ATG8</i> gene family members showed expression changes after treatment with osthole, which induces disease resistance in tobacco, tomato, and pepper. These findings provide a foundation for further analyses of the <i>ATG8</i> gene family in Solanaceae and the mechanism underlying the response to adverse conditions.