AUTHOR=Duan Fangmeng , Song Wenwen 

TITLE=Overexpression of SoCYP85A1 Increases the Accumulation of Castasterone and Confers Enhanced Black Shank Tolerance in Tobacco Through Modulation of the Antioxidant Enzymes’ Activities

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00349

DOI=10.3389/fpls.2019.00349

ISSN=1664-462X

ABSTRACT=<p>Black shank caused by <italic>Phytophthora nicotianae</italic> is one of the most devastating diseases in tobacco production. In this study, we characterized a novel cytochromic resistance gene, <italic>SoCYP85A1</italic>, from spinach, which was upregulated in response to <italic>P. nicotianae</italic> infection. Overexpression of <italic>SoCYP85A1</italic> in tobacco resulted in remarkable resistance to pathogen inoculation, with diverse resistance levels in different transgenic lines. Meanwhile, a significant accumulation of castasterone (CS) was detected in transgenic plants when challenged with the pathogen. Moreover, activities of antioxidant enzymes were enhanced by <italic>SoCYP85A1</italic> in the transgenic lines as compared to those in the wild types inoculated with <italic>P. nicotianae</italic>. In addition, the alteration of CS content resulted in interference of phytohormone homeostasis. Overall, these results demonstrate that <italic>SoCYP85A1</italic> can participate in the defense response to <italic>P. nicotianae</italic> through the involvement of defense enzymes and by interaction with certain phytohormones. Our findings suggest that <italic>SoCYP85A1</italic> could be used as a potential candidate gene for improving resistance to black shank disease in tobacco and other economic crops.</p>