Genome-wide analysis, expansion and expression of the NAC family under drought and heat stresses in bread wheat (T. aestivum L.)

Abstract

The NAC family is one of the largest plant-specific transcription factor families, and some of its members are known to play major roles in plant development and response to biotic and abiotic stresses. Here, we inventoried 488 NAC members in bread wheat ( Triticum aestivum ). Using the recent release of the wheat genome (IWGS RefSeq v1.0), we studied duplication events focusing on genomic regions from 4B-4D-5A chromosomes as an example of the family expansion and neofunctionalization of TaNAC members. Differentially expressed TaNAC genes in organs and in response to abiotic stresses were identified using publicly available RNAseq data. Expression profiling of 23 selected candidate TaNAC genes was studied in leaf and grain from two bread wheat genotypes at two developmental stages in field drought conditions and revealed insights into their specific and/or overlapping expression patterns. This study showed that, of the 23 TaNAC genes, seven have a leaf-specific expression and five have a grain-specific expression. In addition, the grain-specific genes profiles in response to drought depend on the genotype. These genes may be considered as potential candidates for further functional validation and could present an interest for crop improvement programs in response to climate change. Globally, the present study provides new insights into evolution, divergence and functional analysis of NAC gene family in bread wheat.

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.…”

Comprehensive genomic characterization of NAC transcription factor family and their response to salt and drought stress in peanut

“…NAC proteins typically have a conserved NAM domain at the N-terminus and a highly variable domain at the Cterminus, the latter of which is related to specific biological functions. NAC family genes have been studied extensively in a variety of plant species, including gymnosperms and embryophytes [10][11][12][13][14][15][16][17][18][19]. However, until recently, comprehensive analyses of peanut NAC family genes and their response patterns to salt and drought stresses have been limited.…”

Large-Scale Cloning and Comparative Analysis of TaNAC Genes in Response to Stripe Rust and Powdery Mildew in Wheat (Triticum aestivum L.)

“…The number of NAC TF-encoding genes in wheat is much larger than in the model plant Arabidopsis (138) or diploid rice ( Oryza sativa, 170), [ 18 , 19 ]. Recently, the NAC TF family of hexaploid wheat was categorized on the basis of the wheat reference genome TGAC and the IWGS RefSeq v1.0 database [ 20 , 21 ]. A total of 488 full-length sequences containing the NAC domain were annotated (460 high- and 28 low-confidence sequences) [ 20 ].…”

“…Recently, the NAC TF family of hexaploid wheat was categorized on the basis of the wheat reference genome TGAC and the IWGS RefSeq v1.0 database [ 20 , 21 ]. A total of 488 full-length sequences containing the NAC domain were annotated (460 high- and 28 low-confidence sequences) [ 20 ]. Stripe rust and powdery mildew, caused by Puccinia striiformis Westend.…”