Genome-wide investigation of the NAC transcription factor family in melon (Cucumis melo L.) and their expression analysis under salt stress

Abstract

82 melon NAC (CmNAC) genes were identified in melon. We putatively identified the function of CmNAC gene in melon under salt stress. NAC transcription factor proteins play important roles in many biological processes, including plant development and stress responses. To date, few full-length melon NAC proteins have been identified. In this study, 82 melon NAC (CmNAC) genes were identified in the Cucumis melo L. genome. By interrogating our cDNA libraries and transcriptome data from melon under salt stress, and comparison of their phylogenetic relationship with Arabidopsis NAC salt stress-related genes, we putatively identified that the fourth clade of CmNAC genes were involved in the salt stress response, especially the second clade of the group IV of the phylogenetic tree. Expression analysis confirmed that eleven of the twelve CmNAC genes from the group IV were induced in melon seedling roots by salt stress; the other gene was down regulated by salt stress. The expression of CmNAC14 continually increased in 12 h under salt stress, and was selected for transformation into Arabidopsis for functional verification. Overexpression of CmNAC14 increased the sensitivity of transgenic Arabidopsis lines to salt stress, which were simultaneously demonstrated by reduced expression of abiotic stress-response genes and variation in several physiological indices. This study increases our knowledge and may enable further characterization of the roles of CmNAC family in the response to salt stress.

Genome-wide analysis of the NAC transcription factor family in broomcorn millet (Panicum miliaceum L.) and expression analysis under drought stress

“…A total of 180 NAC genes were identified in broomcorn millet. The number of NAC genes in broomcorn millet was higher than the 117 in A. thaliana [41], 151 in rice [60], 104 in pepper [51], 82 in melon [53], 96 in cassava [53], 152 in maize [45], 147 in foxtail millet [47], 152 in soybean [48], and 110 in potato [49], and lower than that of 288 in bread wheat [42] and 188 in Chinese cabbage [50]. There were extensive variations in gene length, predicted protein MW, and protein pI, whereas the gene structures and protein motifs were relatively conserved in the clades, which provided a valuable reference for their analysis and function.…”

“…The grains of broomcorn millet not only have high nutritional value, containing abundant proteins, starch, and a variety of vitamins and minerals, but also have medicinal value and are used in millet wine and other products. The NAC gene family has been widely studied in many species, such as A. thaliana [41], rice [41], wheat [42,43], tartary buckwheat [44], maize [45,46], foxtail millet [47], soybean [48], potato [49], Chinese cabbage [50], pepper [51], cassava [52], melon [53], physic nut [54], apple [55], and pigeon pea [56]. However, no systematic study of the NAC family in broomcorn millet is available.…”

Identification and Expression of NAC Transcription Factors of Vaccinium corymbosum L. in Response to Drought Stress

“…A total of 62 DEGs among 158 VcNACs we identified were noticeably responsive to drought stress on the basis of transcriptome data. Because NAC TFs within the same subgroup tend to share a similar function [63,64], the classification would further help us better understand and predict the potential function of VcNACs. Notably, the subgroup NAC-i includes a number of important NAC genes of Arabidopsis such as AtNAC032 [65], AtNAC019, and AtNAC072 [66,67], which are widely involved in the process of plants' response to abiotic stress, and the formation of anthocyanin.…”

Divergent Evolutionary Patterns of NAC Transcription Factors Are Associated with Diversification and Gene Duplications in Angiosperm

“…Thus, it makes sense to conclude that changes in one key element of a specific network can be constrained by its interactions with other elements, which lead to a relatively low evolution rate and less variable function of members in the Vb subfamily. On the contrary, members from other stress-related subfamilies (e.g., II, IIIa, IIIb, and IVb subfamilies) have integrated responses to environmental stresses into modulation of plant development processes, such as lateral root development (He et al, 2005; Hao et al, 2011; Puranik et al, 2012; Wei et al, 2016), seed germination (Kim et al, 2008; Seo et al, 2010; Wei et al, 2016), flowering (Kim et al, 2007; Wei et al, 2016), and senescence (Balazadeh et al, 2010; Seo and Park, 2011; Yang et al, 2011). Such versatility of NAC functions might result in greater ω values and more sites under positive selection in order to ensure plants' longevity, survival, and reproductive success under various environmental stresses.…”