Liu Yang, Chaofei Ye, Yuting Zhao, Xiaolin Cheng, Yiqiao Wang, Yuan Qing Jiang, Bo Yang. An Oilseed Rape WRKY Type Transcription Factor Regulates ROS Accumulation and Leaf Senescence in Nicotiana benthamiana and Arabidopsis through Modulating Transcription of RbohD and RbohF

An Oilseed Rape WRKY‑Type Transcription Factor Regulates ROS Accumulation and Leaf Senescence in Nicotiana benthamiana and Arabidopsis through Modulating Transcription of RbohD and RbohF

Liu Yang, Chaofei Ye, Yuting Zhao, Xiaolin Cheng, Yiqiao Wang, Yuan‑Qing Jiang, Bo Yang.

Planta

DOI: 10.1007/s00425-018-2868-z

Abstract: Manipulation of leaf senescence process afects agricultural traits of crop plants, including biomass, seed yield and stress resistance. Since delayed leaf senescence usually enhances tolerance to multiple stresses, we analyzed the function of specifc MAPK–WRKY cascades in abiotic and biotic stress tolerance as well as leaf senescence in oilseed rape (Brassica napus L.), one of the important oil crops. In the present study, we showed that expression of one WRKY gene from oilseed rape, BnaWGR1, induced an accumulation of reactive oxygen species (ROS), cell death and precocious leaf senescence both in Nicotiana benthamiana and transgenic Arabidopsis (Arabidopsis thaliana). BnaWGR1 regulates the transcription of two genes encoding key enzymes implicated in production of ROS, that is, respiratory burst oxidase homolog (Rboh) D and RbohF. A dual-luciferase reporter assay confrmed the transcriptional regulation of RbohD and RbohF by BnaWGR1. In vitro electrophoresis mobility shift assay (EMSA) showed that BnaWGR1 could bind to W-box cis-elements within promoters of RbohD and RbohF. Moreover, RbohD and RbohF were signifcantly upregulated in transgenic Arabidopsis overexpressing BnaWGR1. In summary, these results suggest that BnaWGR1 could positively regulate leaf senescence through regulating the expression of RbohD and RbohF genes.