Genome-wide identification and comprehensive analysis of NAC family genes involved in fruit development in kiwifruit (Actinidia)

Abstract

Background NAC transcription factors (TFs) are plant-specific proteins encoded by a large gene family. They play important roles in diverse biological processes, such as plant growth and development, leaf senescence, and responses to biotic or abiotic stresses. Functions of a number of NAC TFs have been identified mainly in model plants. However, very few studies on NAC TFs have been conducted in the fruit tree of kiwifruit. Results Genome-wide NAC genes were identified and their phylogeny, genomic structure, chromosomal location, synteny relationships, protein properties and conserved motifs were analyzed. In addition, the fruit developmental process was evaluated in a new kiwifruit cultivar of Actinidia eriantha ‘Ganlu 1’. And expressions for all those NAC genes were analyzed by quantitative real-time PCR method in fruits of ‘Ganlu 1’ during its developmental process. Our research identified 142 NAC TFs which could be phylogenetically divided into 23 protein subfamilies. The genomic structures of those NAC genes indicated that their exons were between one and ten. Analysis of chromosomal locations suggested that 116 out of 142 NACs distributed on all the 29 kiwifruit chromosomes. In addition, genome-wide gene expression analysis showed that expressions of 125 out of 142 NAC genes could be detected in fruit samples. Conclusion Our comprehensive study provides novel information on NAC genes and expression patterns in kiwifruit fruit. This research would be helpful for future functional identification of NAC genes involved in kiwifruit fruit development.

Genome-wide identification and comprehensive analyses of NAC transcription factor gene family and expression analysis under Fusarium kyushuense and drought stress conditions in Passiflora edulis

“…Most of the PeNAC had three exons or two introns (Figure 2C) and genes within the same phylogenetic clade (Figure 2A) have a similar number of exons. These results are consistent with pitaya (Hu et al, 2022), kiwifruit (Jia et al, 2021), and cucumber (Liu et al, 2018) NAC genes suggesting that the genetic makeup of passion fruit NAC genes are similar with the previously reported species.…”

HuNAC20 and HuNAC25, Two Novel NAC Genes from Pitaya, Confer Cold Tolerance in Transgenic Arabidopsis

“…However, Group B had no member of HuNACs similar to the results from quinoa [43]. Most HuNACs had three exons and two introns (Figure 2), indicating that the genetic structural diversity of NAC in pitaya, which was similar to that of the other species such as kiwifruit [44], Musa Acuminata [45], cucumber [24], and white pear [22]. High segmental duplication events resulted in the expansion of the NAC gene family in H. undatus (Figure 4), which was consistent with the evolutionary pattern in pineapple [38].…”

Comparative Analysis of the Transcriptomes of Persisting and Abscised Fruitlets: Insights into Plant Hormone and Carbohydrate Metabolism Regulated Self-Thinning of Pecan Fruitlets during the Early Stage

“…NAC TFs have been shown to play important roles in various biological processes, as well as responses to abiotic stresses, and are important regulators in a wide range of developmental processes, such as the formation of lateral roots, the development of shoot apical meristem, floral morphogenesis, embryo development, grain nutrient remobilization, and cell wall biosynthesis [56]. In kiwifruit, 74 of 142 NACs were found to be persistently expressed in fruit during the whole developmental process, and crucial candidate NAC genes were shown to be involved in fruit growth and development [57]. Several NAC transcription factors were upregulated in the pedicels of central fruits, which were persisting fruits, in Malus domestica, which might contribute to increased vascular development in the central pedicel in the early developmental stages [6].…”