Affordable Access

Function of the ENOD8 gene in nodules of Medicago truncatula.

University of North Texas
Publication Date
  • Medicago -- Genetics.
  • Medicago
  • Enod8
  • Nodule
  • Esterase
  • Symbiosome
  • Microscopy
  • Biology
  • Chemistry
  • Medicine


To elaborate on the function(s) of the ENOD8 gene in the nodules of M. truncatula, several different experimental approaches were used. A census of the ENOD8 genes was first completed indicating that only ENOD8.1 (nt10554-12564 of GenBank AF463407) is highly expressed in nodule tissues. A maltose binding protein-ENOD8 fusion protein was made with an E. coli recombinant system. A variety of biochemical assays were undertaken with the MBP-ENOD8 recombinant protein expressed in E. coli, which did not yield the esterase activity observed for ENOD8 protein nodule fractions purified from M. sativa, tested on general esterase substrates, α-naphthyl acetate, and p-nitrophenylacetate. Attempts were also made to express ENOD8 in a Pichia pastoris system; no ENOD8 protein could be detected from Pichia pastoris strains which were transformed with the ENOD8 expression cassette. Additionally, it was shown that the ENOD8 protein can be recombinantly synthesized by Nicotiana benthamiana in a soluble form, which could be tested for activity toward esterase substrates, bearing resemblance to nodule compounds, such as the Nod factor. Transcription localization studies using an ENOD8 promoter gusA fusion indicated that ENOD8 is expressed in the bacteroid-invaded zone of the nodule. The ENOD8 protein was also detected in that same zone by immunolocalization. Confocal immunomicroscopy with an affinity-purified anti-ENOD8 oligopeptide antibody showed that the ENOD8 protein localizes at the interface between the plant and the bacteroid-differentiated rhizobia, in the symbiosome membrane or symbiosome space. This suggests a possible link between ENOD8 protein and bacteroid differentiation, nitrogen fixation, or plant defense. These possible functions for ENOD8 could be tested with an ENOD8-RNAi transgenic line devoid of detectable ENOD8 proteins.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times

More articles like this

Transcription of ENOD8 in Medicago truncatula nodu...

on Molecular Plant-Microbe Intera... April 2008

The endosymbiosis-induced genes ENOD40 and CCS52a...

on Molecular Plant-Microbe Intera... October 2002

ENOD8, a novel early nodule-specific gene, is expr...

on Molecular Plant-Microbe Intera... 1993

Purification of ENOD8 proteins from Medicago sativ...

on Plant Physiology and Biochemis... January 2004
More articles like this..