Callose plays an important role in plant development and response to multiple biotic and abiotic stresses. Callose synthase (CalS; EC 2.4.1.34), the main enzyme in callose synthesis, has been studied in a number of crops but not in cucumber (Cucumis sativus L.). In this study, 10 genes encoding putative callose synthase were identified and classified into four clades. Expression levels of the 10 CsCalS genes, which varied considerably, were detected in most analyzed organs. Transcription...