title: Ectopic expression of a maize calreticulin mitigates calcium deficiency-like disorders in sCAX1-expressing tobacco and tomato.
abstract: Deregulated expression of an Arabidopsis H⁺/Ca²⁺ antiporter (sCAX1) in agricultural crops increases total calcium (Ca²⁺) but may result in yield losses due to Ca²⁺ deficiency-like symptoms. Here we demonstrate that co-expression of a maize calreticulin (CRT, a Ca²⁺ binding protein located at endoplasmic reticulum) in sCAX1-expressing tobacco and tomato plants mitigated these adverse effects while maintaining enhanced Ca²⁺ content. Co-expression of CRT and sCAX1 could alleviate the hypersensitivity to ion imbalance in tobacco plants. Furthermore, blossom-end rot (BER) in tomato may be linked to changes in CAX activity and enhanced CRT expression mitigated BER in sCAX1 expressing lines. These findings suggest that co-expressing Ca²⁺ transporters and binding proteins at different intracellular compartments can alter the content and distribution of Ca²⁺ within the plant matrix.
authors.affiliation: Department of Horticulture, Forestry and Recreation Resources, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Wu
authors.forename: Toshiro
authors.initials: T
authors.lastname: Shigaki
authors.forename: Jeung-Sul
authors.initials: JS
authors.lastname: Han
authors.forename: Chang Kil
authors.initials: CK
authors.lastname: Kim
authors.forename: Kendal D
authors.initials: KD
authors.lastname: Hirschi
authors.forename: Sunghun
authors.initials: S
authors.lastname: Park
mesh_terms: D017920:Antiporters / Q000235:genetics* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D037282:Calreticulin / Q000235:genetics* / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism*
chemical_list: D017920:Antiporters; D037282:Calreticulin; D027682:Cation Transport Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; C027614:calcium-hydrogen antiporters; D002118:Calcium