Functional characterization of NAC55 transcription factor from oilseed rape (Brassica napus L.) as a novel transcriptional activator modulating reactive oxygen species accumulation and cell death.
NAC transcription factors (TFs) are plant-specific and play important roles in development, responses to biotic and abiotic cues and hormone signaling. So far, only a few NAC genes have been reported to regulate cell death. In this study, we identified and characterized a NAC55 gene isolated from oilseed rape (Brassica napus L.). BnaNAC55 responds to multiple stresses, including cold, heat, abscisic acid (ABA), jasmonic acid (JA) and a necrotrophic fungal pathogen Sclerotinia sclerotiorum. BnaNAC55 has transactivation activity and is located in the nucleus. BnaNAC55 is able to form homodimers in planta. Unlike ANAC055, full-length BnaNAC55, but not either the N-terminal NAC domain or C-terminal regulatory domain, induces ROS accumulation and hypersensitive response (HR)-like cell death when expressed both in oilseed rape protoplasts and Nicotiana benthamiana. Furthermore, BnaNAC55 expression causes obvious nuclear DNA fragmentation. Moreover, quantitative reverse transcription PCR (qRT-PCR) analysis identified that the expression levels of multiple genes regulating ROS production and scavenging, defense response as well as senescence are significantly induced. Using a dual luciferase reporter assay, we further confirm that BnaNAC55 could activate the expression of a few ROS and defense-related gene expression. Taken together, our work has identified a novel NAC TF from oilseed rape that modulates ROS accumulation and cell death.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Fangfang
F
Niu
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Chen
C
Wang
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Jingli
J
Yan
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Xiaohua
X
Guo
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Feifei
F
Wu
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Bo
B
Yang
Department of Biology, University of British Columbia, Okanagan Campus, Kelowna, BC, V1V 1V7, Canada.
Michael K
MK
Deyholos
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China. jiangyq@nwafu.edu.cn.
Yuan-Qing
YQ
Jiang
D029688:Brassica napus / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors
Brassica napus; Cell death; NAC; Reactive oxygen species; Stress; Transcription factor