Species	Reference gene ID	Possible function	Papers / DOI
Arabidopsis	At4g04850	May act as an electroneutral K⁺/H⁺ antiporter mediating proton efflux from the thylakoid lumen to the chloroplast stroma.	A novel AtKEA gene family, homolog of bacterial K+/H+ antiporters, plays potential roles in K+ homeostasis and osmotic adjustment in Arabidopsis.; 2013; DOI: 10.1371/journal.pone.0081463; PMID: 24278440; https://pubmed.ncbi.nlm.nih.gov/24278440/ | Ion antiport accelerates photosynthetic acclimation in fluctuating light environments.; 2014; DOI: 10.1038/ncomms6439; PMID: 25451040; https://pubmed.ncbi.nlm.nih.gov/25451040/ | Regulation and Levels of the Thylakoid K+/H+ Antiporter KEA3 Shape the Dynamic Response of Photosynthesis in Fluctuating Light.; 2016; DOI: 10.1093/pcp/pcw085; PMID: 27335350; https://pubmed.ncbi.nlm.nih.gov/27335350/ | Rapid hyperosmotic-induced Ca2+ responses in Arabidopsis thaliana exhibit sensory potentiation and involvement of plastidial KEA transporters.; 2016; DOI: 10.1073/pnas.1519555113; PMID: 27528686; https://pubmed.ncbi.nlm.nih.gov/27528686/ | Photosynthesis in Arabidopsis Is Unaffected by the Function of the Vacuolar K +  Channel TPK3.; 2019; DOI: 10.1104/pp.19.00255; PMID: 31053658; https://pubmed.ncbi.nlm.nih.gov/31053658/ | K +  and Cl -  channels/transporters independently fine-tune photosynthesis in plants.; 2019; DOI: 10.1038/s41598-019-44972-z; PMID: 31201341; https://pubmed.ncbi.nlm.nih.gov/31201341/ | Evidence for potassium transport activity of Arabidopsis KEA1-KEA6.; 2019; DOI: 10.1038/s41598-019-46463-7; PMID: 31296940; https://pubmed.ncbi.nlm.nih.gov/31296940/ | Modification of Activity of the Thylakoid H + /K +  Antiporter KEA3 Disturbs ∆pH-Dependent Regulation of Photosynthesis.; 2019; DOI: 10.1104/pp.19.00766; PMID: 31427465; https://pubmed.ncbi.nlm.nih.gov/31427465/ | H +  Transport by K +  EXCHANGE ANTIPORTER3 Promotes Photosynthesis and Growth in Chloroplast ATP Synthase Mutants.; 2020; DOI: 10.1104/pp.19.01561; PMID: 32041909; https://pubmed.ncbi.nlm.nih.gov/32041909/ | Collaboration between NDH and KEA3 Allows Maximally Efficient Photosynthesis after a Long Dark Adaptation.; 2020; DOI: 10.1104/pp.20.01069; PMID: 32978277; https://pubmed.ncbi.nlm.nih.gov/32978277/
Arabidopsis	At4g00630	May act as an electroneutral K⁺/H⁺ antiporter regulating monovalent-cation and pH homeostasis in plastids.	Arabidopsis KEA2, a homolog of bacterial KefC, encodes a K(+)/H(+) antiporter with a chloroplast transit peptide.; 2012; DOI: 10.1016/j.bbamem.2012.04.011; PMID: 22551943; https://pubmed.ncbi.nlm.nih.gov/22551943/ | A novel AtKEA gene family, homolog of bacterial K+/H+ antiporters, plays potential roles in K+ homeostasis and osmotic adjustment in Arabidopsis.; 2013; DOI: 10.1371/journal.pone.0081463; PMID: 24278440; https://pubmed.ncbi.nlm.nih.gov/24278440/ | Envelope K+/H+ Antiporters AtKEA1 and AtKEA2 Function in Plastid Development.; 2016; DOI: 10.1104/pp.16.00995; PMID: 27443603; https://pubmed.ncbi.nlm.nih.gov/27443603/ | Plastidial transporters KEA1 and KEA2 at the inner envelope membrane adjust stromal pH in the dark.; 2021; DOI: 10.1111/nph.17042; PMID: 33111995; https://pubmed.ncbi.nlm.nih.gov/33111995/ | Loss of function of the chloroplast membrane K + /H +  antiporters AtKEA1 and AtKEA2 alters the ROS and NO metabolism but promotes drought stress resilience.; 2021; DOI: 10.1016/j.plaphy.2021.01.010; PMID: 33485149; https://pubmed.ncbi.nlm.nih.gov/33485149/ | Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression.; 2021; DOI: 10.1093/plcell/koab123; PMID: 34235544; https://pubmed.ncbi.nlm.nih.gov/34235544/ | Exogenous sucrose influences KEA1 and KEA2 to regulate abscisic acid-mediated primary root growth in Arabidopsis.; 2022; DOI: 10.1016/j.plantsci.2022.111209; PMID: 35193734; https://pubmed.ncbi.nlm.nih.gov/35193734/
Arabidopsis	At1g01790	May act as an electroneutral K⁺/H⁺ antiporter in chloroplast K⁺ homeostasis, osmotic adjustment and plastid development.	A novel AtKEA gene family, homolog of bacterial K+/H+ antiporters, plays potential roles in K+ homeostasis and osmotic adjustment in Arabidopsis.; 2013; DOI: 10.1371/journal.pone.0081463; PMID: 24278440; https://pubmed.ncbi.nlm.nih.gov/24278440/ | Envelope K+/H+ Antiporters AtKEA1 and AtKEA2 Function in Plastid Development.; 2016; DOI: 10.1104/pp.16.00995; PMID: 27443603; https://pubmed.ncbi.nlm.nih.gov/27443603/ | Evidence for potassium transport activity of Arabidopsis KEA1-KEA6.; 2019; DOI: 10.1038/s41598-019-46463-7; PMID: 31296940; https://pubmed.ncbi.nlm.nih.gov/31296940/ | Plastidial transporters KEA1 and KEA2 at the inner envelope membrane adjust stromal pH in the dark.; 2021; DOI: 10.1111/nph.17042; PMID: 33111995; https://pubmed.ncbi.nlm.nih.gov/33111995/ | Loss of function of the chloroplast membrane K + /H +  antiporters AtKEA1 and AtKEA2 alters the ROS and NO metabolism but promotes drought stress resilience.; 2021; DOI: 10.1016/j.plaphy.2021.01.010; PMID: 33485149; https://pubmed.ncbi.nlm.nih.gov/33485149/ | Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression.; 2021; DOI: 10.1093/plcell/koab123; PMID: 34235544; https://pubmed.ncbi.nlm.nih.gov/34235544/ | Exogenous sucrose influences KEA1 and KEA2 to regulate abscisic acid-mediated primary root growth in Arabidopsis.; 2022; DOI: 10.1016/j.plantsci.2022.111209; PMID: 35193734; https://pubmed.ncbi.nlm.nih.gov/35193734/