The Two Translationally Controlled Tumor Protein Genes, and , Are Negative Modulators in the Defense Response to .

Pathogen stress often significantly decreases cucumber production. However, knowledge regarding the molecular mechanism and signals of cucumber disease resistance is far from complete. Here, we report two translationally controlled tumor protein genes, and , that are both negative modulators in the defense response to . Subcellular localization analysis showed that CsTCTP1 and CsTCTP2 were both localized in the cytoplasm. Expression analysis indicated that the transcript levels of and were linked to the degree of cucumber resistance to . Transient overexpression of either or in cucumber cotyledons impaired resistance to , whereas silencing of either or enhanced cucumber resistance to The relationship of several defense-related genes and ABA and target of rapamycin (TOR) signaling pathway-related genes to the overexpressing and silencing of / in non-infested cucumber plants was investigated. The results indicated that participates in the defense response to by regulating the expression of certain defense-associated genes and/or ABA signaling pathway-associated genes, and participates through regulating the expression of TOR signaling pathway-associated genes. Our findings will guide enhancing the resistance of cucumber to powdery mildew.