An ethylene response-related factor, GbERF1-like, from Gossypium barbadense improves resistance to Verticillium dahliae via activating lignin synthesis

Abstract

An ethylene response-related factor, GbERF1-like, from Gossypium barbadense cv. '7124' involved in the defence response to Verticillium dahliae was characterized. GbERF1-like transcripts present ubiquitously in various tissues, with higher accumulation in flower organs. GbERF1-like was also responsive to defence-related phytohormones and V. dahliae infection. The downregulation of GbERF1-like increased the susceptibility of cotton plants to V. dahliae infection, while overexpression of this gene improved disease resistance in both cotton and Arabidopsis, coupled with activation of the pathogenesis-related proteins. Further analysis revealed that genes involved in lignin synthesis, such as PAL, C4H, C3H, HCT, CCoAOMT, CCR and F5H, showed higher expression levels in the overexpressing cotton and Arabidopsis lines and lower expression levels in the RNAi cotton lines. The expression levels of these genes increased obviously when the GbERF1-like-overexpressing plants were inoculated with V. dahliae. Meanwhile, significant differences in the content of whole lignin could be found in the stems of transgenic and wild-type plants after inoculation with V. dahliae, as revealed by metabolic and histochemical analysis. More lignin could be detected in GbERF1-like-overexpressing cotton and Arabidopsis but less in GbERF1-like-silencing cotton compared with wild-type plants. The ratio of S and G monomers in GbERF1-like-overexpressing cotton and Arabidopsis increased significantly after infection by V. dahliae. Moreover, our results showed that the promoters of GhHCT1 and AtPAL3 could be transactivated by GbERF1-like in vivo based on yeast one-hybrid assays and dual-luciferase reporter assays. Knockdown of GhHCT1 in GbERF1-like over-expressing cotton decreases resistance to V. dahliae. Collectively, our results suggest that GbERF1-like acts as a positive regulator in lignin synthesis and contributes substantially to resistance to V. dahliae in plants.

A high-efficiency CRISPR/Cas9 system for targeted mutagenesis in Cotton (Gossypium hirsutum L.)

“…However, the complex genome feature of allotetraploid cotton presents a new challenge for cotton genes functional analyses and the genetic improvement through transgenic approach. Previously, many cotton genes were identified to be implicated in cotton fibre development45678910111213141516, stress responsees17181920, and pathogen immune regulation through expressed sequence tag (EST)-based cDNA library coupled with conventional RNAi and gene overexpression strategies21222324. With the rapid development of high throughput deep sequencing technologies and bioinformatics, many diploid and allotetraploid cotton species were sequenced and assembled within recent years, including D-genome diploids cotton Gossypium raimondii (DD; 2n = 26)2526, A-genome diploids Gossypium arboreum (AA; 2n = 26)27, ant the AtDt allotetraploid cotton species Gossypium hirsutum and Gossypium barbadense 282930.…”

A novel Gossypium barbadense ERF transcription factor, GbERFb, regulation host response and resistance to Verticillium dahliae in tobacco

“…Although many studies showed that ERFs played important roles in biotic stress, only few of ERF members have been characterized in Sea island cotton (Meng et al 2010;Guo et al 2016). In this study, we isolated a novel ERF gene from Sea island cotton, named GbERFb, which can be induced by exogenous hormones, V. dahliae infection and wounding.…”

“…Sea island cotton (Gossypium barbadense) is usually thought to be more tolerant to V. wilt than other cultivated species. Many biotic stress responsive genes from Sea island cotton were cloned and identified, such as GbERF1-like (Guo et al 2016), GbHcm1 , Gbve1 (Zhang et al 2012), GbWRKY1 . Increasing evidences indicated that the ethylene responsive factors (ERFs) were involved in the resistance to V. wilt (Meng et al 2010;Guo et al 2016).…”

“…Over-expression of GbERF1-like could improve the disease resistance in both cotton and Arabidopsis thaliana against the V. dahliae, while down-regulation of GbERF1-like increased the susceptibility of cotton plants to V. dahliae. Further analysis revealed that GbERF1-like was involved in lignin synthesis (Guo et al 2016).…”

GbSOBIR1 confers Verticillium wilt resistance by phosphorylating the transcriptional factor GbbHLH171 in Gossypium barbadense

“…Studies using methods such as RNA-Seq and proteomic analysis reveal that genes involved in lignin biosynthesis, salicylic acid (SA), jasmonic acid (JA) and brassinosteroid (BR) signalling pathways play important roles in cotton resistance to V. dahliae (Gao et al, 2013a;Wang et al, 2011;Xu et al, 2011). Other genes that may participate in the resistance mechanism include Gbvdr5, GhBAK1, GhSSN, GbWRKY1 and GbERF1-like (Gao et al, 2013b;Guo et al, 2016;Sun et al, 2014;Yang et al, 2015).…”