Abstract:
Nodule-Inception-Like Proteins (NLPs) are plant specific transcription factors that play
significant role in orchestrating nitrogen response. NLPs have been widely studied in vascular
plants, but they are not explicitly reported in many spermatophytes. In current study, in silico
tools were employed for genome wide identification and characterization of NLPs in 20
different spermatophyte plants. The physico-chemical properties, protein motifs, conserved
protein domains and phylogenetic properties of NLPs were assessed and compared to model
plant, Arabidopsis thaliana’s NLPs (AtNLPs). The gene length, protein length and molecular
weight of identified NLPs were greater than AtNLPs. The comparison of iso-electric point of
selected NLPs showed slightly acidic range, which is close to that of AtNLPs. Online tools
employed that all identified NLPs were hydrophilic, and they were found to be localised in the
nucleus, except PpNLPs and AhNLPs which were found to be localized in periplasmic space
and extracellular regions, respectively. Characteristic conserved domains of NLPs, including
PB1 and RWP-RK were found in all the selected NLPs. Gene location analysis results yielded
that chromosome number of many NLPs in the selected plants have not yet been identified.
Protein motifs already identified in AtNLPs were also found in the selected NLPs. Gene
structure analysis showed that both exons and introns were present in majority of NLPs. But
CsNLPs, MgNLPs, MaNLPs and BrNLPs showed lack of introns. Phylogenetic analysis of the identified NLPs classified them into 5 distinct groups. Group I, II and III were classified based on previous studies done on NLPs from different plants. Group IV contained NLPs from Amborella trichopoda and Brachypodium stacei. Group V was recognised as the most evolutionary diverged group.
