loading page

NtMYB12a acts downstream of sucrose to inhibit fatty acid accumulation by targeting lipoxygenase and lipase genes in tobacco
  • +7
  • Zhong Wang,
  • Zefeng Li,
  • Shanshan Wang,
  • Yansong Xiao,
  • Xiaodong Xie,
  • Mingzhu Wu,
  • Jinlong Yu,
  • Lirui Cheng,
  • Aiguo Yang,
  • Jun Yang
Zhong Wang
Zhengzhou Tobacco Research Institute
Author Profile
Zefeng Li
Zhengzhou Tobacco Research Institute
Author Profile
Shanshan Wang
Xiangyang Cigarette Factory of China Tobacco Hubei Industrial Co., Ltd.
Author Profile
Yansong Xiao
Chenzhou Tobacco Company of Hunan Province
Author Profile
Xiaodong Xie
Zhengzhou Tobacco Research Institute
Author Profile
Mingzhu Wu
Zhengzhou Tobacco Research Institute
Author Profile
Jinlong Yu
Chenzhou Tobacco Company of Hunan Province
Author Profile
Lirui Cheng
Chinese Academy of Agricultural Sciences Institute of Tobacco Research
Author Profile
Aiguo Yang
Tobacco Research Institute, Chinese Academy of Agricultural Sciences
Author Profile

Abstract

MYB12 promotes flavonol biosynthesis in plants by targeting several early biosynthesis genes (EBGs) of this pathway. The transcriptions of these EBGs are also induced by sucrose signal. However, whether MYB12 is activated by sucrose signal and the other roles of MYB12 in regulating plant metabolism are poorly understood. In this study, two NtMYB12 genes were cloned from Nicotiana tabacum. Both NtMYB12a and NtMYB12b are involved in regulating flavonoids biosynthesis in tobacco. NtMYB12a is further shown to inhibit the accumulation of fatty acid (FA) in tobacco leaves and seeds. Posttranslational activation and chromatin immunoprecipitation assays demonstrate that NtMYB12a directly promotes the transcriptions of NtLOX6, NtLOX5, NtSFAR4, and NtGDSL2, which encode lipoxygenase (LOX) or lipase enzymes catalyzing the degradation of FA. NtLOX6 and NtLOX5 are shown to prevent the accumulation of FA in the mature seeds, and significantly reduced the percentage of polyunsaturated fatty acids (PUFAs) in tobacco. Sucrose stimulates the transcription of NtMYB12a, and loss function of NtMYB12a partially suppresses the decrease of FA content in tobacco seedlings caused by sucrose treatment. The regulation of sucrose on the expression of NtLOX6 and NtGDSL2 genes is mediated by NtMYB12a, but those of NtLOX5 and NtSFAR4 genes are independent of sucrose.

Peer review status:UNDER REVIEW

12 Aug 2020Submitted to Plant, Cell & Environment
13 Aug 2020Assigned to Editor
13 Aug 2020Submission Checks Completed
17 Aug 2020Reviewer(s) Assigned