Agriculture Reference
In-Depth Information
sativum
(pea), and
MtLYK3
/
MtLYK4
and
MtNFP
in
Medicago truncatula
,
respectively (Indrasumunar 2007; Indrasumunar
et al
. 2010).
Unlike the
NFR
genes identified in the other legume species, both
NFR1
and
NFR5
genes in soybean are duplicated, resulting in
GmNFR1ʱ/GmNFR1β
and
GmNFR5ʱ/GmNFR5β
. The duplicated copies of
GmNFR5
are slightly
more conserved than the duplicated copies of
GmNFR1
, at both the nucleotide
and protein sequence level (Table 1). In regards to extracellular and
transmembrane domains, the duplicated copies of
GmNFR5
are also more
similar than the
GmNFR1
duplicated copies. However, the kinase domain of
both
GmNFR1
and
GmNFR5
duplicated copies are equally similar (Table 1).
GmNFR1ʱ
and
β
appear to have slightly different functions, where
GmNFR1ʱ
has a higher affinity for Nod factor than
GmNFR1β
. In contrast,
GmNFR5ʱ
and
β
, which share a high degree of similarity, appear to complement one
another (Indrasumunar 2007; Indrasumunar
et al
. 2010).
Table 1. Similarity between duplicated gene copies of GmNFR1 and
GmNFR5
Nucleotides
level
Protein
level
Extra
cellular
Trans
Membrane
Kinase
Domain
GmNFR1ʱ
and
GmNFR1β
94%
90%
82%
74%
96%
GmNFR5ʱ
and
GmNFR5β
95%
93%
91%
96%
96%
GmNFR1ʱ
and
GmNFR5ʱ/β
are required for the earliest physiological and
cellular responses to Nod factors. As has been reported for Nod factor receptor
genes of other legume species,
GmNFR1
and
GmNFR5
are required for root
hair swelling and curling. They are also required for downstream nodulation
signaling events, such as the induced expression of critical nodulation genes.
Mutations in any of
GmNFR1ʱ
or
GmNFR5ʱ/β
result in plants that either do
not respond, or show an attenuated response, to
B. japonicum
inoculation
(Indrasumunar 2007; Indrasumunar
et al
. 2010).
