Open AccessInteractions of WRKY 15 and WRKY 33 transcription factors and their roles in the resistance of oilseed rape to Sclerotinia infection
Author(s) -
Liu Fei,
Li Xiaoxia,
Wang Meirong,
Wen Jing,
Yi Bin,
Shen Jinxiong,
Ma Chaozhi,
Fu Tingdong,
Tu Jinxing
Publication year - 2018
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12838
Subject(s) - wrky protein domain , biology , sclerotinia sclerotiorum , arabidopsis , transactivation , transcription factor , gene , leptosphaeria maculans , genetics , botany , mutant
Summary WRKY transcription factors are known to participate in the defence responses of higher plants. However, little is known about the roles of such proteins, especially regarding their functions in the resistance of oilseed rape ( Brassica napus ) to Sclerotinia sclerotiorum , a necrotrophic fungal pathogen that causes stem rot. In this study, we identified Bn WRKY 33 as a S. sclerotiorum ‐responsive gene that positively regulates resistance to this pathogen by enhancing the expression of genes involved in camalexin synthesis and genes regulated by salicylic acid ( SA ) and jasmonic acid ( JA ). We also identified a S. sclerotiorum ‐responsive region in the promoter of Bn WRKY 33 , which we revealed to be a relatively conserved W‐box region in the promoters of homologous genes in different species. Using this S. sclerotiorum ‐responsive region as bait in a yeast one‐hybrid assay, we identified another WRKY transcription factor, Bn WRKY 15 , and observed that both Bn WRKY 15 and Bn WRKY 33 could bind to this region. In addition, Bn WRKY 15 overexpression simultaneously increased the susceptibility of B . napus to S. sclerotiorum and down‐regulated Bn WRKY 33 after different durations of infection. Furthermore, Bn WRKY 15, which contains a transcriptional repression domain, exhibited reduced transactivation ability and could reduce the transactivation ability of Bn WRKY 33 in Arabidopsis protoplast assays. Therefore, we suggest that the increased susceptibility of Bn WRKY 15 ‐overexpressing plants results from reduced Bn WRKY 33 expression, which is due to the inhibition of Bn WRKY 33 transcriptional activation by Bn WRKY 15.