AUTHOR=Meng Xiangnan , Yu Yang , Zhao Junyue , Cui Na , Song Tiefeng , Yang Yun , Fan Haiyan 

TITLE=The Two Translationally Controlled Tumor Protein Genes, CsTCTP1 and CsTCTP2, Are Negative Modulators in the Cucumis sativus Defense Response to Sphaerotheca fuliginea

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00544

DOI=10.3389/fpls.2018.00544

ISSN=1664-462X

ABSTRACT=<p>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, <italic>CsTCTP1</italic> and <italic>CsTCTP2</italic>, that are both negative modulators in the <italic>Cucumis sativus</italic> defense response to <italic>Sphaerotheca fuliginea</italic>. Subcellular localization analysis showed that CsTCTP1 and CsTCTP2 were both localized in the cytoplasm. Expression analysis indicated that the transcript levels of <italic>CsTCTP1</italic> and <italic>CsTCTP2</italic> were linked to the degree of cucumber resistance to <italic>S. fuliginea</italic>. Transient overexpression of either <italic>CsTCTP1</italic> or <italic>CsTCTP2</italic> in cucumber cotyledons impaired resistance to <italic>S. fuliginea</italic>, whereas silencing of either <italic>CsTCTP1</italic> or <italic>CsTCTP2</italic> enhanced cucumber resistance to <italic>S. fuliginea.</italic> The relationship of several defense-related genes and ABA and target of rapamycin (TOR) signaling pathway-related genes to the overexpressing and silencing of <italic>CsTCTP1</italic>/<italic>CsTCTP2</italic> in non-infested cucumber plants was investigated. The results indicated that <italic>CsTCTP1</italic> participates in the defense response to <italic>S. fuliginea</italic> by regulating the expression of certain defense-associated genes and/or ABA signaling pathway-associated genes, and <italic>CsTCTP2</italic> participates through regulating the expression of TOR signaling pathway-associated genes. Our findings will guide enhancing the resistance of cucumber to powdery mildew.</p>