Jasmonic acid-responsive RRTF1 transcription factor controls DTX18 gene expression in hydroxycinnamic acid amide secretion

Abstract

Jasmonates (JAs) are plant hormones that regulate the biosynthesis of many secondary metabolites, such as hydroxycinnamic acid amides (HCAAs), through jasmonic acid (JA)-responsive transcription factors (TFs). HCAAs are renowned for their role in plant defense against pathogens. The multidrug and toxic compound extrusion transporter DETOXIFICATION18 (DTX18) has been shown to mediate the extracellular accumulation of HCAAs p-coumaroylagmatine (CouAgm) at the plant surface for defense response. However, little is known about the regulatory mechanism of DTX18 gene expression by TFs. Yeast one-hybrid screening using the DTX18 promoter as bait isolated the key positive regulator redox-responsive TF 1 (RRTF1), which is a member of the AP2/ethylene-response factor family of proteins. RRTF1 is a JA-responsive factor that is required for the transcription of the DTX18 gene, and it thus promotes CouAgm secretion at the plant surface. As a result, overexpression of RRTF1 caused increased resistance against the fungus Botrytis cinerea, whereas rrtf1 mutant plants were more susceptible. Using yeast two-hybrid screening, we identified the BTB/POZ-MATH (BPM) protein BPM1 as an interacting partner of RRTF1. The BPM family of proteins acts as substrate adaptors of CUL3-based E3 ubiquitin ligases, and we found that only BPM1 and BPM3 were able to interact with RRTF1. In addition, we demonstrated that RRTF1 was subjected to degradation through the 26S proteasome pathway and that JA stabilized RRTF1. Knockout of BPM1 and BPM3 in bpm1/3 double mutants enhanced RRTF1 accumulation and DTX18 gene expression, thus increasing resistance to the fungus B. cinerea. Our results provide a better understanding of the fine-tuned regulation of JA-induced TFs in HCAA accumulation.

The Role of Hydroxycinnamic Acid Amide Pathway in Plant Immunity

“…These plant hormones regulated the synthesis of compounds. JA regulated the biosynthesis of many secondary metabolites, including HCAAs ( Li et al, 2021a ). The accumulation of p -coumaroylagmatine in leaves was higher at 48 h after JA treatment, and reached the highest level at 48 h after JA/ET combined treatment.…”

The Pathogen-Induced MATE Gene TaPIMA1 Is Required for Defense Responses to Rhizoctonia cerealis in Wheat

“…In Arabidopsis , there are 56 MATE transporters that play important roles in plant growth, development, and resistance to biotic and abiotic stresses [ 37 , 67 ]. However, only a few MATE transporters with disease resistance, including resistance transporter EDS5 to viral and bacterial pathogens [ 38 , 68 ], P. infestans and B. cinerea resistance transporter AtDTX18 [ 40 , 69 ], and P. syringeae susceptibility transporter ADS1 [ 39 ], have been characterized. The studies on functions of MATE transporters in plant immunity/defense are limited in crops, particularly in wheat.…”

“…In Arabidopsis , EDS5 contributes to the transport and accumulation of SA, while exogenous SA stimulation induces the expression of EDS5 and enhances the resistance to biotrophic pathogens P. syringae [ 51 ]. Unlike EDS5, involved in the SA-mediated resistance pathway [ 38 , 49 , 51 ], TaPIMA1 did not response to SA but exhibited a strong inductive response to JA, similar to the MATE transporter AtDTX18 [ 69 ]. Taken together, these results suggested that H 2 O 2 and JA might participate in the TaPIMA1 -mediated resistance to R. cerealis in wheat.…”

A Non-Shedding Fruit Elaeis oleifera Palm Reveals Perturbations to Hormone Signaling, ROS Homeostasis, and Hemicellulose Metabolism

“…This is notable, given the similarities between the molecular basis of meristem maintenance and the abscission process and the importance of the environment in modulating the acquisition of AZ competence and function [14,16,56,57]. In contrast, other DEGs (LOC105059334, LOC105054588, LOC105060890, LOC105050553, LOC105035740, LOC105043386, LOC105043733) for ERF-related TF genes are upregulated in the NSd variant, the majority of which are related to abiotic and biotic stress [58][59][60][61][62][63] and one (LOC105042035) for fruit ripening [64]. Finally, there is one DEG (LOC105053311) that encodes LHT1, involved in the uptake of ACC, the precursor of ET [32], which has lower expression in the ripe fruit NSd AZ than in the normal Sd AZ.…”