Ins
pired by the availability of
de novo transcri
ptome of horse gram (
Macrotyloma uniflorum) and recent develo
pments in systems biology studies, the first ever global
protein–
protein interactome (PPI) ma
p was constructed for this highly drought-tolerant legume. Large-scale studies of PPIs and the constructed database would
provide rationale behind the inter
play at cascading translational levels for drought stress-ada
ptive mechanisms in horse gram. Using a bidirectional a
pproach (interolog and domain-based), a high-confidence interactome ma
p and database for horse gram was constructed. Available transcri
ptomic information for shoot and root tissues of a sensitive (M-191; genoty
pe 1) and a drought-tolerant (M-249; genoty
pe 2) genoty
pe of horse gram was utilized to draw com
parative PPI subnetworks under drought stress. High-confidence 6804 interactions were
predicted among 1812
proteins covering about one-fourth of the horse gram
proteome. The highest number of interactions (33.86%) in horse gram interactome matched with
Arabidopsis PPI data. The to
p five hub nodes mostly included ubiquitin and heat-shock-related
proteins. Higher numbers of PPIs were found to be res
ponsive in shoot tissue (416) and root tissue (2228) of genoty
pe 2 com
pared with shoot tissue (136) and root tissue (579) of genoty
pe 1. Characterization of PPIs using gene ontology analysis revealed that kinase and transferase activities involved in signal transduction, cellular
processes, nucleocyto
plasmic trans
port,
protein ubiquitination, and localization of molecules were most res
ponsive to drought stress. Hence, these could be framed in stress ada
ptive mechanisms of horse gram. Being the first legume global PPI ma
p, it would
provide new insights into gene and
protein regulatory networks for drought stress tolerance mechanisms in horse gram. Information com
piled in the form of database (
MauPIR) will
provide the much needed high-confidence systems biology information for horse gram genes,
proteins, and involved
processes. This information would ease the effort and increase the efficacy for similar studies on other legumes. Public access is available at
p://14.139.59.221/MauPIR/" class="extLink">http://14.139.59.221/MauPIR/.