Genome-wide Identification and Abiotic Stress Response Pattern Analysis of NF-Y Gene Family in Peanut (Arachis Hypogaea L.)

Abstract

The nuclear factor Y (NF-Y) transcription factor (TF) family consists of three subfamilies NF-YA, NF-YB and NF-YC. Many studies have proven that NF-Y complex plays multiple essential roles in stress response in Arabidopsis and other plant species. However, little attention has been given to these genes in peanut. In this study, thirty-three AhNF-Y genes were identified in cultivated peanut and they were distributed on 16 chromosomes. A phylogenetic analysis of the NF-Y amino acid sequences indicated that the peanut NF-Y proteins were clustered in pairs at the end of the branches and showed high conservation with previous reported plant NF-Ys. Evolutionary history analysis showed that only segmental duplication contributed to expansion of this gene family. Analysis of the 1500-bp regulatory regions upstream the start codon showed that, except for AhNF-YB6, peanut NF-Ys contained at least one abiotic stress response element in their regulatory region. Expression patterns of peanut NF-Ys in 22 tissues and developmental stages were analyzed. A few NF-Ys showed universal expression patterns, while most NF-Ys showed specific expression patterns. Through RNA-seq and qRT-PCR analyses, expression of six AhNF-Y genes was induced under salt stress in leaves or roots. In addition, AhNF-YA4/8/11, NF-YB4 and NF-YC2/8 also responded to osmotic stress, ABA (abscisic acid) and salicylic acid (SA) treatment.