Contribution of CaBPM4, a BTB Domain–Containing Gene, to the Response of Pepper to Phytophthora capsici Infection and Abiotic Stresses

Abstract

The Broad-complex Tramtrack and Bric-a-brac (BTB) domain participates in plant responses to biotic and abiotic stresses, however its role is unknown in pepper plants. CaBPM4 has meprin and TRAF homology (MATH) and BTB domains at its N-and C-termini, respectively, and it contains a 1589-bp full-length cDNA that encodes a protein containing 403 amino acids. In this study, the pepper gene CaBPM4 (Capsicum annuum BTB-POZ and MATH domain protein) was cloned, and its role in responses to Phytophthora capsici, cold, drought, and salt stress were characterized. The results of quantitative RT-PCR revealed that CaBPM4 was down-regulated under P. capsici infection, salicylic acid, H 2 O 2 , and abscisic acid treatments, while abiotic stresses, including salt, cold, and drought, enhanced its transcript level. Furthermore, CaBPM4 silencing significantly impaired resistance to P. capsici, apparently by altering the transcript level of defense-related genes CaPR1, CaDEF1, and CaSAR82 and reducing root activity. However, CaBPM4-silenced plants exhibited remarkably increased peroxidase activity and decreased malondialdehyde concentrations, indicating that CaBPM4 may enhance resistance to salt and drought stress. Further study should focus on the mechanism by which CaBPM4 regulates the defense response to P. capsici infection and abiotic stresses.Broad-complex Tramtrack and Bric-a-brac (BTB) domain, also known as POX virus and Zinc finger (POZ) domain, is evolutionarily conserved and reported to be involved in transcriptional regulation [14,15] and targeting proteins for degradation [16]. BTB domain was first discovered in Drosophila [15], and since then, its vital roles in hormone-induced signaling transduction and plant responses to biotic and abiotic stresses have been revealed [17,18]. For example, in soybean, GmBTB expression was induced strongly by Phytophthora sojae infection [19]. The potato (Solanum tuberosum) BTB-containing protein NRL1 can interact with the positive immunity regulator NbSWAP70 in Nicotiana benthamiana and also suppress plant immunity against Phytophthora infestans infections [20]. Expression of Arabidopsis NPR1 in wheat, transgenic tobacco, rice, and tomato enhanced plant resistance to pathogen attacks [21][22][23][24]. Furthermore, the BTB-containing protein ARIA also affected the abscisic acid (ABA)-mediated signaling pathway through interactions with a transcription factor ABF2 [25]. The BTB domain-containing protein gene family of tomato was also well-known to be related closely to abiotic stresses [26].Many BTB/POZ proteins contain a secondary protein domain, such as a meprin and TRAF (tumor necrosis factor receptor associated factor) homology (MATH) domain, a tumor necrosis factor receptor-associated element [27]. A previous study suggested that MATH domain-containing proteins positively regulate defense responses to abiotic stresses in Arabidopsis and rice [28]. Different functional roles have been identified for BTB proteins, including transcription repression, cytoskeleton regulation, and prote...

Transcriptomic analysis of bakanae disease resistant and susceptible rice genotypes in response to infection by Fusarium fujikuroi

“…Generally, BTB domain participates in plant responses against biotic and abiotic stresses. He et al, [37] reported down regulation of BTB gene under Phytophthora capsici infection. Upregulation of this gene in resistant genotype may have role in defence against F. fujikuroi.…”

“…Generally, BTB domain participates in plant responses against biotic and abiotic stresses. He et al, [37] reported down regulation of BTB gene under Phytophthora capsici infection. Upregulation of this gene in resistant genotype may have role in defence against F. fujikuroi.Results of the selected DEGs showed that the qRT-PCR was consistent with the RNA-Seq results showing similar expression pattern of up-and down-regulated genes by using both, RNA-Seq and qRT-PCR, analyses.…”

Bioinformatic Analysis of the BTB Gene Family in Paulownia fortunei and Functional Characterization in Response to Abiotic and Biotic Stresses

“…For example, the Ankyrin subfamily can respond to drought, salt stress, and ABA treatment, and PfBTB3/4/31/32/27/52/61 in P. fortunei belongs to the same subfamily, so we infer that these genes may be involved in similar plant stress tolerance processes. In addition, members of the MATH subfamily have been reported to be involved in plant resistance to biotic stress processes, such as CaBPM4 ( CaBTB51 ) of the MATH subfamily of pepper, which is highly regulated under the Phytophthora capsici infection [ 36 ]. These studies suggest that within the different subfamilies of BTB, each subfamily member is involved in plant-specific biological processes.…”

Genome-Wide Association Mapping Reveals Novel Putative Gene Candidates Governing Reproductive Stage Heat Stress Tolerance in Rice

“…Ubiquitin ligases are frequently implicated under heat stress in rice ( Mittal et al, 2012 ; Zhang et al, 2012 ; González-Schain et al, 2016 ). Broad-complex Tramtrack and the Bric-a-brac (BTB) domain/POX virus and Zinc finger (POZ) (BTB/POX) domain-containing proteins (chromosome 6) are implicated in transcriptional regulation and protein degradation ( He et al, 2019 ). These BPM proteins are reported to negatively regulate the degradation of DREB2A and contribute to plant thermo-tolerance ( Morimoto et al, 2017 ).…”