Cuiling Yuan, Chunjuan Li, Xiaodong Lu, Xiaobo Zhao, Caixia Yan, Juan Wang, Quanxi Sun & Shihua Shan

BMC Plant Biology volume 20, Article number: 454 (2020)

Abstract

Background

Peanut is one of the most important oil crop species worldwide. NAC transcription factor (TF) genes play important roles in the salt and drought stress responses of plants by activating or repressing target gene expression. However, little is known about NAC genes in peanut.

Results

We performed a genome-wide characterization of NAC genes from the diploid wild peanut species Arachis duranensis and Arachis ipaensis, which included analyses of chromosomal locations, gene structures, conserved motifs, expression patterns, and cis-acting elements within their promoter regions. In total, 81 and 79 NAC genes were identified from A. duranensis and A. ipaensis genomes. Phylogenetic analysis of peanut NACs along with their Arabidopsis and rice counterparts categorized these proteins into 18 distinct subgroups. Fifty-one orthologous gene pairs were identified, and 46 orthologues were found to be highly syntenic on the chromosomes of both A. duranensis and A. ipaensis. Comparative RNA sequencing (RNA-seq)-based analysis revealed that the expression of 43 NAC genes was up- or downregulated under salt stress and under drought stress. Among these genes, the expression of 17 genes in cultivated peanut (Arachis hypogaea) was up- or downregulated under both stresses. Moreover, quantitative reverse transcription PCR (RT-qPCR)-based analysis revealed that the expression of most of the randomly selected NAC genes tended to be consistent with the comparative RNA-seq results.

Conclusion

Our results facilitated the functional characterization of peanut NAC genes, and the genes involved in salt and drought stress responses identified in this study could be potential genes for peanut improvement.

See: https://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-020-02678-9

Figure 1:

Chromosome location of NAC genes on each chromosomes of A. duranensis and A. ipaensis. a Diagrammatic sketch of distribution of NAC genes on each chromosome (black bars). The approximate location of each NAC gene are shown at the left side of each chromosome. b-c The NAC genes’ distribution on each chromosome. The number of NAC genes on each chromosome is shown in brackets