AUTHOR=Li Linxuan , Zhu Tingting , Song Yun , Luo Xiumei , Feng Li , Zhuo Fengping , Li Fuguang , Ren Maozhi 

TITLE=Functional Characterization of Target of Rapamycin Signaling in Verticillium dahliae

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.00501

DOI=10.3389/fmicb.2019.00501

ISSN=1664-302X

ABSTRACT=<p>More than 200 plants have been suffering from Verticillium wilt caused by <italic>Verticillium dahliae</italic> (<italic>V. dahliae</italic>) across the world. The target of rapamycin (TOR) is a lethal gene and controls cell growth and development in various eukaryotes, but little is known about TOR signaling in <italic>V. dahliae</italic>. Here, we found that <italic>V. dahliae</italic> strain is hypersensitive to rapamycin in the presence of rapamycin binding protein VdFKBP12 while the deletion mutant aaa<italic>vdfkbp12</italic> is insensitive to rapamycin. Heterologous expressing <italic>VdFKBP12</italic> in <italic>Arabidopsis</italic> conferred rapamycin sensitivity, indicating that <italic>VdFKBP12</italic> can bridge the interaction between rapamycin and TOR across species. The key across species of TOR complex 1 (TORC1) and TORC2 have been identified in <italic>V. dahliae</italic>, suggesting that TOR signaling pathway is evolutionarily conserved in eukaryotic species. Furthermore, the RNA-seq analysis showed that ribosomal biogenesis, RNA polymerase II transcription factors and many metabolic processes were significantly suppressed in rapamycin treated cells of <italic>V. dahliae</italic>. Importantly, transcript levels of genes associated with cell wall degrading enzymes (CWEDs) were dramatically down-regulated in TOR-inhibited cells. Further infection assay showed that the pathogenicity of <italic>V. dahliae</italic> and occurrence of Verticillium wilt can be blocked in the presence of rapamycin. These observations suggested that VdTOR is a key target of <italic>V. dahliae</italic> for controlling and preventing Verticillium wilt in plants.</p>