Characterization of barley (Hordeum vulgare L.) NAC transcription factors suggests conserved functions compared to both monocots and dicots

Abstract

BackgroundThe NAC transcription factor family is involved in the regulation of traits in both monocots and dicots of high agronomic importance. Understanding the precise functions of the NAC genes can be of utmost importance for the improvement of cereal crop plants through plant breeding. For the cereal crop plant barley (Hordeum vulgare L.) only a few NAC genes have so far been investigated.ResultsThrough searches in publicly available barley sequence databases we have obtained a list of 48 barley NAC genes (HvNACs) with 43 of them representing full-length coding sequences. Phylogenetic comparisons to Brachypodium, rice, and Arabidopsis NAC proteins indicate that the barley NAC family includes members from all of the eight NAC subfamilies, although by comparison to these species a number of HvNACs still remains to be identified. Using qRT-PCR we investigated the expression profiles of 46 HvNACs across eight barley tissues (young flag leaf, senescing flag leaf, young ear, old ear, milk grain, late dough grain, roots, and developing stem) and two hormone treatments (abscisic acid and methyl jasmonate).ConclusionsComparisons of expression profiles of selected barley NAC genes with the published functions of closely related NAC genes from other plant species, including both monocots and dicots, suggest conserved functions in the areas of secondary cell wall biosynthesis, leaf senescence, root development, seed development, and hormone regulated stress responses.

Senescence-associated Barley NAC (NAM, ATAF1,2, CUC) Transcription Factor Interacts with Radical-induced Cell Death 1 through a Disordered Regulatory Domain

“…These levels were comparable with that obtained by activation caused by interaction between the positive control p53 and SV40 large antigen (38). A stepwise decrease in activity was detected by C-terminal trun- (25). Alignments and the tree were constructed using ClustalX 2.1 (28).…”

“…First strand cDNA synthesis was performed as described (25). qRT-PCR was performed using the ABI Prism 7900HT Sequence Detection System with the Power SYBR Green PCR master mix (Applied Biosystems).…”

“…Recently, barley HvNAC005 and HvNAC013 were identified as genes up-regulated during senescence (25). To investigate their expression pattern in more detail, a time course experiment was performed.…”

“…HvNAC005 and HvNAC013 Belong to Phylogenetically Different Subgroups-To investigate the phylogenetic clustering of HvNAC005 and HvNAC013, an unrooted tree of predicted barley NAC proteins (25) was constructed based on their conserved NAC domains (Fig. 2).…”

“…This was associated with increased residual nitrogen, zinc, and iron in the flag leaf, thereby demonstrating a role for NAC genes in nutrient redistribution to the developing grain during leaf senescence (24). We have provided an inventory of 48 barley NAC genes, of which several transcripts accumulated in senescing tissue (25).…”