Identification and Characterization of Abiotic Stress-Responsive NF-YB Family Genes in .

Nuclear factor YB (NF-YB) are plant-specific transcription factors that play a critical regulatory role in plant growth and development as well as in plant resistance against various stresses. In this study, a total of 49 genes were identified from the genomes of and . Multiple sequence alignment analysis showed that all of these NF-YB members contain DNA binding domain, NF-YA interaction domain and NF-YC interaction domain. Phylogenetic analysis suggested that these NF-YB proteins could be classified into five distinct clusters. We also analyzed the exon-intron organizations and conserved motifs of these genes and their deduced proteins. We also found many stress-related -acting elements in their promoter region. In addition, analyses on genechip for and transcriptome data for indicated that these genes exhibited a distinct expression pattern in various tissues; many of these could be induced by drought and/or salt treatments. In particular, RT-qPCR analysis revealed that the expression levels of gene pairs and were significantly up-regulated under NaCl and mannitol treatments, indicating that they are most likely involved in salt and drought stress response. Taken together, our study on family genes in is valuable for their functional characterization, as well as for the application of genes in genetic breeding for high-yield and high-resistance alfalfa.