Ethylene-Responsive AP2/ERF Transcription Factor MACD1 Participates in Phytotoxin-Triggered Programmed Cell Death

Abstract

To investigate plant programmed cell death (PCD), we developed the model system using phytotoxin AAL, which is produced by necrotrophic pathogen Alternaria alternata f. sp. lycopersici, and AAL-sensitive Nicotiana umbratica. We previously reported that ethylene (ET) signaling plays a pivotal role in AAL-triggered cell death (ACD). However, downstream signaling of ET to ACD remains unclear. Here, we show that the modulator of AAL cell death 1 (MACD1), which is an APETALA2/ET response factor (ERF) transcription factor, participates in ACD and acts downstream of ET signaling during ACD. MACD1 is a transcriptional activator and MACD1 overexpression plants showed earlier ACD induction than control plants, suggesting that MACD1 positively regulates factors affecting cell death. To investigate the role of MACD1 in PCD, we used Arabidopsis thaliana and a structural analog of AAL, fumonisin B1 (FB1). FB1-triggered cell death was compromised in ET signaling and erf102 mutants. The loh2 mutants showed sensitivity to AAL, and the loh2-1/erf102 double mutant compromised ACD, indicating that ERF102 also participates in ACD. To investigate the PCD-associated genes regulated by ERF102, we compared our microarray data using ERF102 overexpression plants with the database of upregulated genes by AAL treatment in loh2 mutants, and found genes under the control of ERF102 in ACD.

Synchronization of Developmental Processes and Defense Signaling by Growth Regulating Transcription Factors

“…ERFs constitute a plant-specific transcriptional factor superfamily of 147 members in Arabidopsis [62], influence a number of developmental processes, and are also involved in plant response to biotic stress [63]–[65]. It might be relevant to mention that several ERFs we identified as putative targets of GRF1/3 are implicated in defense responses.…”

“…It might be relevant to mention that several ERFs we identified as putative targets of GRF1/3 are implicated in defense responses. For example ERF5 (AT5G47230) plays vital role in phytotoxin-triggered programmed cell death [65] and in regulating both stress tolerance and leaf growth inhibition [66]. In addition, ERF2 (At5g47220) induces high levels of defense gene expression and enhances plant resistance to Fusarium oxysporum when overexpressed in Arabidopsis [67], [68].…”

Novel type of adenylyl cyclase participates in tabtoxinine-β-lactam-induced cell death and occurrence of wildfire disease inNicotiana benthamiana

“…4 The host-specific fungal AAL toxins are reported to induce ethylene signaling-dependent PCD in susceptible tomato plants. 5 Our previous report also showed apoptotic cell death is closely associated with lettuce developing of bacterial rot and eggplants developing of necrotic leaf spot caused by Pseudomonas cichorii. 6,7 Inoculation with a host-nonspecific toxin-producing strain of Pseudomonas syringae is also reportedly to induced apoptotic PCD, suggesting induction of PCD by host-non specific bacterial toixins.…”

Comparative Analysis of MicroRNA Expression in Three Paulownia Species with Phytoplasma Infection

“…The target gene of miR172 a-3p encode AP2 and the target gene of miR172d encode EREBP and glutathione peroxidase (GPX). In Arabidopsis thaliana, an AP2/ERF transcription factor (MACD1), was found to be involved in phytotoxin-triggered programmed cell death [44]. Huang, et al [45] reported that AP2/ERF transcription factors were reported to interact with the MAPK, and jasmonic acid, salicylic acid, ethene, and H 2 O 2 pathways to improve the ability of tomato plants to respond to yellow leaf curly virus.…”