Catalytically inactive mPGKc could not rescue the <i>pgkc-1</i> mutant phenotype.

<p><b>(A)</b> Protein sequences of the conserved Glutamate179 regions of PGK proteins. AtPGKc, <i>Arabidopsis thaliana</i> cytosolic PGK; OsPGKc, <i>Oryza sativa</i> cytosolic PGK; DmPGK, <i>Drosophila melanogaster</i> PGK; ScPGK, <i>Saccharomyces cerevisiae</i> PGK; EcPGK, <i>Escherichia coli</i> PGK. Glutamate179 in AtPGKc is labeled with a red dot. <b>(B)</b> <i>PGKc</i> expression level. <b>(C)</b> Pollen germination rate. <b>(D)</b> Average length of pollen tubes. <b>(E)</b> Average width of pollen tubes. Bars represent mean ± SEM. Asterisks indicate significant differences versus WT as determined using Student’s <i>t</i>-test (** = p < 0.001).