*2.1. Genome-Wide Identification and Analysis of the Tomato BAG Gene Family*

To identify the tomato BAG gene family, the BAG domain (PF02179) was used as a query to perform an HMMER (v3.3.2) search against the tomato proteome downloaded from Tomato Genome Annotation ITAG4.0 database (https://solgenomics.net, accessed on 10 October 2021). At the same time, a comprehensive search was carried out by using the amino acid sequence of *Arabidopsis thaliana* according to a previous study [4], of which seven AtBAG proteins were obtained from the *Arabidopsis thaliana* Araport11. The reliability of *SlBAG* gene sequences and genome sequences was further confirmed by searching the NCBI database (https://www.ncbi.nlm.nih.gov, accessed on 20 October 2021). The genomic regions, transcripts, and products were from Tomato Genome version SL4.0 (https://solgenomics.net, accessed on 10 October 2021) and NCBI data comparison. The molecular weight (Mw) and isoelectric point (pI) were calculated by ProtParam on the ExPASy Server (https://web.expasy.org/protparam, accessed on 25 October 2021).

#### *2.2. Phylogenetic Analysis*

The BAG protein sequences were downloaded from database *Solanum lycopersicum* ITAG4.0, *Arabidopsis thaliana* Araport11, and *Oryza sativa* v7.0, respectively. Multiple sequence alignments of BAG proteins were carried out using MUSCLE and the tree was constructed by PhyML method (phylogeny.fr/simple\_phylogeny.cgi, accessed on 5 November 2021).

#### *2.3. Motif Analysis of SlBAG Proteins*

The conserved motifs of tomato SlBAGs were predicted by the MEME tool (Version 5.4.1, http://meme-suite.org/tools/meme, accessed on 11 December 2021). The number of BAG conserved domain was validated using NCBI conserved domains (CDD) and shown using the HMMER web server (Biosequence analysis using profile hidden Markov Models|HMMER).

#### *2.4. Gene Structure and Cis-Element Analysis of SlBAG Genes*

The Gene Structure Display Server (http://gsds.cbi.pku.edu.cn, accessed on 15 December 2021) was used for the gene structure determination. The cis-regulatory elements of the SlBAG gene promoters were analyzed by the PLANTCARE database (http: //bioinformatics.psb.ugent.be/webtools/plantcare/html, accessed on 20 December 2021) and the elements were displayed on the TBtool software (version v1.0986853, https: //github.com/CJ-Chen/TBtools, accessed on 28 December 2021).
