The coordination of melatonin and anti‐bacterial activity by EIL5 underlies ethylene‐induced disease resistance in cassava

Abstract

Ethylene and melatonin are widely involved in plant development and environmental stress responses. However, the role of their direct relationship in the immune response and the underlying molecular mechanisms in plants remain elusive. Here, we found that Xanthomonas axonopodis pv. manihotis (Xam) infection increased endogenous ethylene levels, which positively modulated plant disease resistance through activating melatonin accumulation in cassava. In addition, the ethylene-responsive transcription factor ETHYLENE INSENSITIVE LIKE5 (MeEIL5), a positive regulator of disease resistance, was essential for ethylene-induced melatonin accumulation and disease resistance in cassava. Notably, the identification of heat stress transcription factor 20 (MeHsf20) as an interacting protein of MeEIL5 indicated the association between ethylene and melatonin in plant disease resistance. MeEIL5 physically interacted with MeHsf20 to promote the transcriptional activation of the gene encoding N-acetylserotonin O-methyltransferase 2 (MeASMT2), thereby improving melatonin accumulation. Moreover, MeEIL5 promoted the physical interaction of MeHsf20 and pathogen-related gene 3 (MePR3), resulting in improved anti-bacterial activity of MePR3. This study illustrates the dual roles of MeEIL5 in fine-tuning MeHsf20-mediated coordination of melatonin biosynthesis and anti-bacterial activity, highlighting the ethylene-responsive MeEIL5 as the integrator of ethylene and melatonin signals in the immune response in cassava.

Caffeic Acid O-Methyltransferase Gene Family in Mango (Mangifera indica L.) with Transcriptional Analysis under Biotic and Abiotic Stresses and the Role of MiCOMT1 in Salt Tolerance

“…The Danzhou Mango Germplasm Resource Bank of the Ministry of Agriculture and Rural Affairs provided various tissues and annual seedlings such as roots, young leaves, young stems, flowers, fruits, and seeds, and the variety was “Guifei”. Seedlings were potted in soil (professional growing mix, soil/vermiculite = 2:1) in a greenhouse at 28 °C under a 16/8 h light/dark photoperiod [ 70 , 71 , 72 ].…”

Recent Advances in Dissecting the Function of Ethylene in Interaction between Host and Pathogen

“…Specifically, infection with Xanthomonas axonopodis pv manihotis ( Xam ) led to an increase in endogenous ET content and the transcription level of ET INSENSITIVE LIKE5 (MeEIL5). MeEIL5 actively modulated disease resistance by interacting with MeHsf20, subsequently promoting the transcriptional activation of the gene encoding N -acetylserotonin O -methyltransferase 2 (MeASMT2) and stimulating melatonin accumulation in cassava . ABA plays a multifaceted role in various plant processes, including stomatal regulation and the initiation of adaptive responses to both biotic and abiotic stressors .…”

“…MeEIL5 actively modulated disease resistance by interacting with MeHsf20, subsequently promoting the transcriptional activation of the gene encoding N-acetylserotonin O-methyltransferase 2 (MeASMT2) and stimulating melatonin accumulation in cassava. 111 ABA plays a multifaceted role in various plant processes, including stomatal regulation and the initiation of adaptive responses to both biotic and abiotic stressors. 112 Chen and colleagues 113 reported that the WRKY8 TF inhibited tobacco mosaic virus (TMV-cg) infection by regulating ABA and ET pathways, indicating crosstalk between ABA and ET signaling during TMV-cg− Arabidopsis interaction.…”

Phytomelatonin: A key regulator of redox and phytohormones signaling against biotic/abiotic stresses

“…A recent finding indicated that Xanthomonas axonopodis pv. manihotis ( Xam ) infestation increases levels of intracellular ETH, which modulates disease resistance in plants by inducing the production of MT in cassava roots [ 117 ]. Moreover, the ethylene-responsive transcription factor ETHYLENE INSENSITIVE LIKE 5 (EIL5), known to promote disease resistance, is crucial for the ethylene-induced accumulation of MT in cassava.…”

“…Heat stress transcription factor 20 (Hsf20) physically interacts with EIL5 and led to the activation of the MT biosynthetic gene ASMT2 ( Fig. 6 ), suggesting a link between ETH and MT in plant disease resistance [ 117 ]. Furthermore, increasing of EIL5 protein promotes Hsf20-specific interaction with PR3 , thereby contributing to the anti-bacterial properties of PR3 .…”