The Nin-Like Protein (Nlp) Family in Common Bean: Genome-Wide Identification, Evolution and Expression Analysis

Abstract

One of the plant-specific transcription factor families that play an important role in responses to nitrogen deficiency is NODULE INCEPTION-like (NIN-like) proteins (NLPs). However, the properties and evolutionary relationships of NIN genes in P. vulgaris, which enable nodule formation naturally, have not been studied yet. 12 Pvul-NIN genes have been identified in this study and the approximate positions of these genes have been determined. At the same time, several biochemical and physicochemical properties of NIN-like proteins have been elucidated. Comparisons between both monocot and dicot, but also nodule binding and non-nodule binding species were considered when investigating the evolutionary relationships of NIN genes. 16 duplication events (14 segmental and 2 tandem) have been shown to play a role in the expansion of the NIN gene family in P. vulgaris. In addition, comparative expression analysis of NIN genes was performed by processing publicly available RNAseq data and different levels of Pvul-NIN gene expression under both salt and drought stress were detected, suggesting the roles of Pvul-NIN gene for abiotic stress response. Expression levels of NIN genes have also been investigated in different plant tissues and have been shown to be intensely expressed in nodules and root tissues. This is the first study on the in-silico detection and characterization of Pvul-NIN genes to examine gene expression levels in common bean. The results could therefore provide the basis for future studies of functional characterization of Pvul-NIN genes.