Species	Reference gene ID	Possible function	Papers / DOI
Arabidopsis	At1g28230	Proton-coupled purine transporter mediating adenine and trans-zeatin uptake.	Transport of cytokinins mediated by purine transporters of the PUP family expressed in phloem, hydathodes, and pollen of Arabidopsis.; 2003; DOI: 10.1046/j.1365-313x.2003.01700.x; PMID: 12662305; https://pubmed.ncbi.nlm.nih.gov/12662305/ | Recycling of pyridoxine (vitamin B6) by PUP1 in Arabidopsis.; 2013; DOI: 10.1111/tpj.12195; PMID: 23551747; https://pubmed.ncbi.nlm.nih.gov/23551747/