Small Physcomitrella Patens Cora-type Mg Ion Transporter (ppmgts), Separation, Functional Identification And Interaction Of Initial Exploration

Magnesium is an abundant divalent cation in plant cells and a metal central of photosynthesis reaction.Fluctuation in stromal of Mg²⁺ concentration by light is an important regulator of Calvin cycle,but a molecular mechanism for the determination of light-induced fluctuation in free Mg²⁺ has been pursued for long time. Physcomitrella patens are being used as a new plant model to study cell development and ion movement.Both single layer filament and targeted mutagenesis are provided one of the easiest systems for analyzing ion cross the membrane,and,for understanding the fluctuation mechanism of free Mg²⁺ in chloroplast during photosynthesis.Using a blasting a moss genomic data combined with molecular methods,we identified a PpMGT(Physcomitrella patens Magnesium transporter) gene encoding putative Mg²⁺ transport protein.PpMGT is widely expressed in whole life circle of physcomitrella patens and functionally complemented a bacterial mutant lacking Mg²⁺ transport capability.Further fluorescent measurement produced similar results.By analysis of ion competition and pH assay,it was found that PpMGT was highly sensitive to Cu²⁺ or Co²⁺ at micromolar levels and driven by proton gradient. Further experiments for isolating interactors,screening mutants and recording ion current signals will be applied,and for deeply dissecting molecular mechanism in light-induced Mg²⁺ movement.