Identification and bioinformatics comparison of two novel phosphatases in monoecious and gynoecious cucumber lines

Abstract

Two Arabidopsis thaliana genes from the PP2C family of protein phosphatases (AtABI1 and AtABI2) were used to find orthologous genes in the Cucumis sativus L. cv. Borszczagowski (cucumber) genome. Cucumber has been used as a model plant for sex expression studies because although it has been defined as a monoecious species, numerous genotypes are known to produce only female, only male, or hermaphroditic flowers. We identified two new orthologous genes of AtABI1 and AtABI2 in the cucumber genome and named them CsABI1 and CsABI2. To determine the relationships between the regulation of CsABI1 and CsABI2 and flower morphogenesis in cucumber, we performed various computational analyses to define the structure of the genes, and to predict regulatory elements and protein motifs in their sequences. We also performed an expression analysis to identify differences in the expression levels of CsABI1 and CsABI2 in vegetative and generative tissues (leaf, shoot apex, and flower buds) of monoecious (B10) and gynoecious (2gg) cucumber lines. We found that the expressions of CsABI1 and CsABI2 differed in male and female floral buds, and correlated these findings with the abscisic acid signaling pathways in male and female flowers.