Species	Reference gene ID	Possible function	Papers / DOI
Arabidopsis	At4g13670	Exhibits zinc-dependent disulfide isomerase activity.	Chloroplast small heat shock protein HSP21 interacts with plastid nucleoid protein pTAC5 and is essential for chloroplast development in Arabidopsis under heat stress.; 2013; DOI: 10.1105/tpc.113.111229; PMID: 23922206; https://pubmed.ncbi.nlm.nih.gov/23922206/