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Nitrate-regulated glutaredoxins control Arabidopsis thaliana primary root growth.

Patterson, Kurt; Walters, Laura; Cooper, Andrew; Olvera, Jocelyn; Rosas, Miguel; Rasmusson, Allan LU and Escobar, Matthew (2015) In Plant Physiology
Abstract
Nitrogen is an essential soil nutrient for plants, and lack of nitrogen commonly limits plant growth. Soil nitrogen is typically available to plants in two inorganic forms: nitrate and ammonium. To better understand how nitrate and ammonium differentially affect plant metabolism and development, we performed transcriptional profiling of the shoots of ammonium-supplied and nitrate-supplied Arabidopsis thaliana plants. Seven genes encoding class III glutaredoxins were found to be strongly and specifically induced by nitrate. RNA silencing of four of these glutaredoxin genes (AtGRXS3/4/5/8) resulted in plants with increased primary root length (~25% longer than wild-type) and decreased sensitivity to nitrate-mediated inhibition of primary... (More)
Nitrogen is an essential soil nutrient for plants, and lack of nitrogen commonly limits plant growth. Soil nitrogen is typically available to plants in two inorganic forms: nitrate and ammonium. To better understand how nitrate and ammonium differentially affect plant metabolism and development, we performed transcriptional profiling of the shoots of ammonium-supplied and nitrate-supplied Arabidopsis thaliana plants. Seven genes encoding class III glutaredoxins were found to be strongly and specifically induced by nitrate. RNA silencing of four of these glutaredoxin genes (AtGRXS3/4/5/8) resulted in plants with increased primary root length (~25% longer than wild-type) and decreased sensitivity to nitrate-mediated inhibition of primary root growth. Increased primary root growth is also a well-characterized phenotype of many cytokinin-deficient plant lines. We determined that nitrate induction of glutaredoxin gene expression was dependent upon cytokinin signaling and that cytokinins could activate glutaredoxin gene expression independent of plant nitrate status. In addition, crosses between "long-root" cytokinin-deficient plants and "long-root" glutaredoxin-silenced plants generated hybrids that displayed no further increase in primary root length (i.e. epistasis). Collectively, these findings suggest that AtGRXS3/4/5/8 operate downstream of cytokinins in a signal transduction pathway that negatively regulates plant primary root growth in response to nitrate. This pathway could allow Arabidopsis to actively discriminate between different nitrogen sources in the soil, with the preferred nitrogen source, nitrate, acting to suppress primary root growth (vertical dimension) in concert with its well-characterized stimulatory effect on lateral root growth (horizontal dimension). (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Plant Physiology
publisher
American Society of Plant Biologists
external identifiers
  • pmid:26662603
  • scopus:84956844567
  • wos:000369343300030
ISSN
1532-2548
DOI
10.1104/pp.15.01776
language
English
LU publication?
yes
id
e4b03dd5-af0f-4b76-b7d8-dad47264ae51 (old id 8504953)
date added to LUP
2016-01-08 09:31:11
date last changed
2017-08-27 03:29:57
@article{e4b03dd5-af0f-4b76-b7d8-dad47264ae51,
  abstract     = {Nitrogen is an essential soil nutrient for plants, and lack of nitrogen commonly limits plant growth. Soil nitrogen is typically available to plants in two inorganic forms: nitrate and ammonium. To better understand how nitrate and ammonium differentially affect plant metabolism and development, we performed transcriptional profiling of the shoots of ammonium-supplied and nitrate-supplied Arabidopsis thaliana plants. Seven genes encoding class III glutaredoxins were found to be strongly and specifically induced by nitrate. RNA silencing of four of these glutaredoxin genes (AtGRXS3/4/5/8) resulted in plants with increased primary root length (~25% longer than wild-type) and decreased sensitivity to nitrate-mediated inhibition of primary root growth. Increased primary root growth is also a well-characterized phenotype of many cytokinin-deficient plant lines. We determined that nitrate induction of glutaredoxin gene expression was dependent upon cytokinin signaling and that cytokinins could activate glutaredoxin gene expression independent of plant nitrate status. In addition, crosses between "long-root" cytokinin-deficient plants and "long-root" glutaredoxin-silenced plants generated hybrids that displayed no further increase in primary root length (i.e. epistasis). Collectively, these findings suggest that AtGRXS3/4/5/8 operate downstream of cytokinins in a signal transduction pathway that negatively regulates plant primary root growth in response to nitrate. This pathway could allow Arabidopsis to actively discriminate between different nitrogen sources in the soil, with the preferred nitrogen source, nitrate, acting to suppress primary root growth (vertical dimension) in concert with its well-characterized stimulatory effect on lateral root growth (horizontal dimension).},
  author       = {Patterson, Kurt and Walters, Laura and Cooper, Andrew and Olvera, Jocelyn and Rosas, Miguel and Rasmusson, Allan and Escobar, Matthew},
  issn         = {1532-2548},
  language     = {eng},
  month        = {12},
  publisher    = {American Society of Plant Biologists},
  series       = {Plant Physiology},
  title        = {Nitrate-regulated glutaredoxins control Arabidopsis thaliana primary root growth.},
  url          = {http://dx.doi.org/10.1104/pp.15.01776},
  year         = {2015},
}