PMID- 22793647
OWN - NLM
STAT- MEDLINE
DCOM- 20140211
LR  - 20130731
IS  - 1549-7801 (Electronic)
IS  - 0738-8551 (Linking)
VI  - 33
IP  - 3
DP  - 2013 Sep
TI  - Asparagine: an amide of particular distinction in the regulation of symbiotic 
      nitrogen fixation of legumes.
PG  - 309-27
LID - 10.3109/07388551.2012.695770 [doi]
AB  - Symbiotic nitrogen fixation is tightly regulated by a range of fine processes at 
      the nodule level, over which the host plant has overall control through the whole 
      life of the plant. The operation of this control at the nodule level is not yet 
      fully understood, but greater knowledge will ultimately lead to a better 
      improvement of N2 fixation through the use of crop legumes and genetic 
      engineering of crop plants for higher performance. It has been suggested that, 
      nodule responses to the nutritional complexity of the rhizosphere environment 
      involve a great deal of coordination of sensing and signal transduction. This 
      regulation can be achieved through several mechanisms, including changes in 
      carbon metabolism, oxygen supply and/or overproduction of reactive oxygen and 
      nitrogen species. Recently, the cycling of amino acids observed between the plant 
      and bacteroid fractions suggests a new and important regulatory mechanism 
      involved in nodule responses. Most of the recent transcriptional findings are 
      consistent with the earlier biochemical and physiological reports. Current 
      research revealed unique advances for nodule metabolism, especially on the 
      regulation of asparagine synthetase gene expression and the control of asparagine 
      (ASN) to N2 fixing activity. A large amount of ASN is found accumulating in the 
      root nodules of the symbiotic plants under restricted environments, such as 
      drought, salinity and nutrient deficiency. Exceptionally, ASN phloem feeding has 
      resulted in an increased concentration of the ASN amide in nodules followed by a 
      remarkable decrease in nodule activity. In this review, recent progress 
      concerning the possible role of ASN in whole-plant-based down-regulation of 
      symbiotic N2 fixation will be reviewed.
FAU - Sulieman, Saad
AU  - Sulieman S
AD  - Department of Agronomy, Faculty of Agricultur, University of Khartoum, Shambat, 
      Khartoum North, Sudan.
FAU - Tran, Lam-Son Phan
AU  - Tran LS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
DEP - 20120716
PL  - England
TA  - Crit Rev Biotechnol
JT  - Critical reviews in biotechnology
JID - 8505177
RN  - 7006-34-0 (Asparagine)
RN  - N762921K75 (Nitrogen)
SB  - IM
MH  - Asparagine/*metabolism
MH  - Fabaceae/*metabolism/*microbiology
MH  - Nitrogen/*metabolism
MH  - *Nitrogen Fixation
MH  - Root Nodules, Plant/metabolism/microbiology
MH  - Symbiosis
EDAT- 2012/07/17 06:00
MHDA- 2014/02/12 06:00
CRDT- 2012/07/17 06:00
PHST- 2012/07/17 06:00 [entrez]
PHST- 2012/07/17 06:00 [pubmed]
PHST- 2014/02/12 06:00 [medline]
AID - 10.3109/07388551.2012.695770 [doi]
PST - ppublish
SO  - Crit Rev Biotechnol. 2013 Sep;33(3):309-27. doi: 10.3109/07388551.2012.695770. 
      Epub 2012 Jul 16.