Genome-wide identification, characterisation and functional evaluation of WRKY genes in the sweet potato wild ancestor Ipomoea trifida (H.B.K.) G. Don. under abiotic stresses

Abstract

BackgroundWRKY DNA-binding protein (WRKY) is a large gene family involved in plant responses and adaptation to salt, drought, cold and heat stresses. Sweet potato from the genus Ipomoea is a staple food crop, but the WRKY genes in Ipomoea species remain unknown to date. Hence, we carried out a genome-wide analysis of WRKYs in Ipomoea trifida (H.B.K.) G. Don., the wild ancestor of sweet potato.ResultsA total of 83 WRKY genes encoding 96 proteins were identified in I. trifida, and their gene distribution, duplication, structure, phylogeny and expression patterns were studied. ItfWRKYs were distributed on 15 chromosomes of I. trifida. Gene duplication analysis showed that segmental duplication played an important role in the WRKY gene family expansion in I. trifida. Gene structure analysis showed that the intron-exon model of the ItfWRKY gene was highly conserved. Meanwhile, the ItfWRKYs were divided into five groups (I, IIa + IIb, IIc, IId + IIe and III) on the basis of the phylogenetic analysis on I. trifida and Arabidopsis thaliana WRKY proteins. In addition, gene expression profiles confirmed by quantitative polymerase chain reaction showed that ItfWRKYs were highly up-regulated or down-regulated under salt, drought, cold and heat stress conditions, implying that these genes play important roles in response and adaptation to abiotic stresses.ConclusionsIn summary, genome-wide identification, gene structure, phylogeny and expression analysis of WRKY gene in I. trifida provide basic information for further functional studies of ItfWRKYs and for the molecular breeding of sweet potato.

Genome-wide Identification of WRKY transcription factor family members in sorghum (Sorghum bicolor (L.) moench)

“…In contrast, sorghum contains fewer WRKY genes than maize, soybean, or rice [ 23 , 45 , 46 ]. The present findings in sorghum, an important cereal crop and a model plant for drought tolerance, add to the recent identification of WRKY genes in a variety of plant species, including chickpea [ 26 ], Chinese jujube ( Ziziphus jujube ) [ 47 ], sugar beet ( Beta vulgaris ) [ 48 ], coffee ( Coffea arabica ) [ 49 ], pepper [ 50 ], eggplant ( Solanum melongena ) [ 51 ], Asian legume crops [ 52 ], sweet potato ( Ipomoea batatas ) [ 53 ], and pearl millet ( Pennisetum glaucum ) [ 54 ].…”

Comparative Transcriptome and Proteome Analysis of Salt-Tolerant and Salt-Sensitive Sweet Potato and Overexpression of IbNAC7 Confers Salt Tolerance in Arabidopsis

“…TFs are critical components that regulate plant signal transduction and gene expression in response to various biotic and abiotic stresses (Erpen et al, 2018;Zhu et al, 2018;Li et al, 2019). In our transcriptome data, a total of 1,618 differentially expressed TFs were examined, including bZIP, bHLH, ERF, MYB, NAC, and WRKY, suggesting their important roles in regulating the salt tolerance of sweet potato.…”

“…Plants' response to salt stress involves sophisticated and diverse tolerance mechanisms that are activated and integrated by the transcription of thousands of genes with enormous biological roles (Kant et al, 2007;Zhu, 2016). Transcription factors (TFs) are pivotal because they are involved in the regulation of signal transduction and the transcription of many stress-related genes, such as bZIP, MYB, WRKY, AP2/ERF, and NAC proteins (Erpen et al, 2018;Zhu et al, 2018;Li et al, 2019;Yang et al, 2019). NACs are one of the largest plant-specific TFs, and have been widely isolated from various species, such as Arabidopsis and rice (Nuruzzaman et al, 2010), potato (Singh et al, 2013), tomato (Jin et al, 2020) and maize (Wang et al, 2020).…”

Identification, expression analysis, and functional characterization of salt stress‐responsive genes of AP2/ERF transcription factors in sweetpotato

“…Deciphering the regulatory mechanisms of stress signaling pathways is pivotal for improving crop productivity. Transcription factors (TFs) are critical components among the stress‐responsive genes; their protein products are involved in the regulation of signal transduction and the transcription of other stress‐related genes, such as bZIP, WRKY, NAC, and APETALA2/ethylene responsive factors (AP2/ERF) proteins (Erpen, Devi, Grosser, & Dutt, 2018; Li et al., 2019; Yang et al., 2019; Zhu et al., 2018).…”