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A Redox-Mediated Modulation of Stem Bolting in Transgenic Nicotiana sylvestris Differentially Expressing the External Mitochondrial NADPH Dehydrogenase.

Liu, Yunjun LU ; Nunes-Nesi, Adriano; Wallström, Sabá LU ; Lager, Ida LU ; Michalecka, Agnieszka LU ; Norberg, Fredrik LU ; Widell, Susanne LU ; Fredlund, Kenneth M; Fernie, Alisdair R and Rasmusson, Allan LU (2009) In Plant Physiology 150. p.1248-1259
Abstract
Cytosolic NADPH can be directly oxidized by a calcium-dependent NADPH dehydrogenase, NDB1, present in the plant mitochondrial electron transport chain. However, little is known regarding the impact of modified cytosolic NADPH reduction levels on growth and metabolism. Nicotiana sylvestris plants overexpressing potato NDB1 displayed early bolting whereas sense-suppression of the same gene led to delayed bolting, with consequential changes in flowering time. The phenotype was dependent on light irradiance, but not linked to any change in biomass accumulation. Whereas the leaf NADPH/NADP(+)-ratio was unaffected, the stem NADPH/NADP(+)-ratio was altered following the genetic modification and strongly correlated to the bolting phenotype.... (More)
Cytosolic NADPH can be directly oxidized by a calcium-dependent NADPH dehydrogenase, NDB1, present in the plant mitochondrial electron transport chain. However, little is known regarding the impact of modified cytosolic NADPH reduction levels on growth and metabolism. Nicotiana sylvestris plants overexpressing potato NDB1 displayed early bolting whereas sense-suppression of the same gene led to delayed bolting, with consequential changes in flowering time. The phenotype was dependent on light irradiance, but not linked to any change in biomass accumulation. Whereas the leaf NADPH/NADP(+)-ratio was unaffected, the stem NADPH/NADP(+)-ratio was altered following the genetic modification and strongly correlated to the bolting phenotype. Metabolic profiling of the stem displayed that the NADP(H) change affected relatively few, albeit central, metabolites, including 2-oxoglutarate, glutamate, ascorbate, sugars and hexose phosphates. Consistent with the phenotype, the modified NDB1 level also affected expression of putative floral meristem identity genes of the SQUAMOSA and LEAFY types. Further evidence for involvement of the NADPH redox in stem development was seen in the distinct decrease in the stem apex NADPH/NADP(+)-ratio during bolting. Additionally, the potato NDB1 protein was specifically detected in mitochondria, and a survey of its abundance in major organs revealed that the highest levels are present in green stems. The results thus strongly suggest that NDB1 in the mitochondrial electron transport chain can, by modifying cell redox levels, specifically affect developmental processes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Physiology
volume
150
pages
1248 - 1259
publisher
American Society of Plant Biologists
external identifiers
  • wos:000268696800012
  • scopus:67650139087
ISSN
1532-2548
DOI
10.1104/pp.109.136242
language
English
LU publication?
yes
id
62dcef59-4f13-4899-b61a-c49a8d3c22a1 (old id 1412486)
date added to LUP
2009-06-11 09:48:30
date last changed
2017-09-03 03:36:32
@article{62dcef59-4f13-4899-b61a-c49a8d3c22a1,
  abstract     = {Cytosolic NADPH can be directly oxidized by a calcium-dependent NADPH dehydrogenase, NDB1, present in the plant mitochondrial electron transport chain. However, little is known regarding the impact of modified cytosolic NADPH reduction levels on growth and metabolism. Nicotiana sylvestris plants overexpressing potato NDB1 displayed early bolting whereas sense-suppression of the same gene led to delayed bolting, with consequential changes in flowering time. The phenotype was dependent on light irradiance, but not linked to any change in biomass accumulation. Whereas the leaf NADPH/NADP(+)-ratio was unaffected, the stem NADPH/NADP(+)-ratio was altered following the genetic modification and strongly correlated to the bolting phenotype. Metabolic profiling of the stem displayed that the NADP(H) change affected relatively few, albeit central, metabolites, including 2-oxoglutarate, glutamate, ascorbate, sugars and hexose phosphates. Consistent with the phenotype, the modified NDB1 level also affected expression of putative floral meristem identity genes of the SQUAMOSA and LEAFY types. Further evidence for involvement of the NADPH redox in stem development was seen in the distinct decrease in the stem apex NADPH/NADP(+)-ratio during bolting. Additionally, the potato NDB1 protein was specifically detected in mitochondria, and a survey of its abundance in major organs revealed that the highest levels are present in green stems. The results thus strongly suggest that NDB1 in the mitochondrial electron transport chain can, by modifying cell redox levels, specifically affect developmental processes.},
  author       = {Liu, Yunjun and Nunes-Nesi, Adriano and Wallström, Sabá and Lager, Ida and Michalecka, Agnieszka and Norberg, Fredrik and Widell, Susanne and Fredlund, Kenneth M and Fernie, Alisdair R and Rasmusson, Allan},
  issn         = {1532-2548},
  language     = {eng},
  pages        = {1248--1259},
  publisher    = {American Society of Plant Biologists},
  series       = {Plant Physiology},
  title        = {A Redox-Mediated Modulation of Stem Bolting in Transgenic Nicotiana sylvestris Differentially Expressing the External Mitochondrial NADPH Dehydrogenase.},
  url          = {http://dx.doi.org/10.1104/pp.109.136242},
  volume       = {150},
  year         = {2009},
}