Comprehensive analysis of MAPK gene family in Populus trichocarpa and physiological characterization of PtMAPK3‐1 in response to MeJA induction

Abstract

Mitogen‐activated protein kinases (MAPKs) play important roles in plant growth and development, as well as hormone and stress responses by signaling to eukaryotic cells, through MAPK cascade, the presence of various cues; thereby, regulating various responses. The MAPK cascade consists mainly of three gene families, MAPK, MAPKK, and MAPKKK, which activate downstream signaling pathways through sequential phosphorylation. Although the MAPK cascade gene family has been reported in several species, there is a lack of comprehensive analysis in poplar. We identified 21 MAPK genes, 11 MAPKK genes, and 104 MAPKKK genes in Populus trichocarpa. The phylogenetic classification was supported by conservative motif, gene structure and motif analysis. Whole genome duplication has an important role in the expansion of MAPK cascade genes. Analysis of promoter cis‐elements and expression profiles indicates that MAPK cascade genes have important roles in plant growth and development, abiotic and biotic stresses, and phytohormone response. Expression profiling revealed a significant upregulation of PtMAPK3‐1 expression in response to drought, salt and disease stresses. Poplar transiently overexpressing PtMAPK3‐1 and treated with methyl jasmonic acid (MeJA) had higher catalase and peroxidase levels than non‐overexpressing poplar. This work represents the first complete inventory of the MAPK cascade in P. trichocarpa, which reveals that PtMAPK3‐1 is induced by the MeJA hormone and participates in the MeJA‐induced enhancement of the antioxidant enzyme system.

Functional Analysis of SmMYB39 in Salt Stress Tolerance of Eggplant (Solanum melongena L.)

“…The MAPK family is a highly conserved group of serine/threonine protein kinases widely present in eukaryotes and involved in various cellular signaling pathways. Transcriptomic data in ginger (Zingiber officinale Roscoe) under salt stress revealed that differentially expressed genes activate MAPK signaling pathways in response to salt stress [42]. We speculate that SmMYB39 may interact with the aforementioned proteins, activating salt stress defense-related genes and promoting the transmission of stress-related hormone pathways, thereby enhancing eggplant's resistance to salt stress.…”

Exogenous methyl jasmonate mediates tolerance of heat stress in Korean fir (Abies koreana)

“…Treatment with 100 µM MeJA was associated with increased expression of MYB4 and MYB88 in Glycyrrhiza uralensis (Li et al 2020), and ERF TFs in California poppy (Yamada et al 2020) and tomato fruit (Yu et al 2018). In addition, strong upregulation of the MPK was observed in Populus trichocarpa exposed to 0.5 mM MeJA (Wu et al 2023).…”

“…For example, JA regulates expression of NAC family transcription factors (TFs), which play vital roles in promoting plant adaptations to abiotic stress (Olsen et al 2005;Jeong et al 2010;Sun et al 2013;Zhou et al 2013;Liang et al 2014). In addition, upregulation of LpNAC037, LpNAC045, Online ISSN 1863-5474 Print ISSN 1863 and LpNAC054 occurs in exogenous MeJA-treated leaves of perennial ryegrass under heat stress (Su et al 2021), upregulation of ethylene response factor (ERF) has been observed in MeJA-treated kiwi fruit under heat stress, and expression of bHLH, MYB, and MPK increases following treatment with exogenous MeJA in various plant species (Yue et al 2012;Zhao et al 2013;Pan et al 2019;Li et al 2020;Wu et al 2023). Heat shock proteins (HSPs), controlled by heat stress transcription factors, play a central role in the heat stress response (Kotak et al 2007;Scharf et al 2012).…”

Endogenous Hormone Levels and Transcriptomic Analysis Reveal the Mechanisms of Bulbil Initiation in Pinellia ternata

“…Additional investigation revealed that the enzymatic activities of catalase and peroxidase in both transgenic and wild-type Populustrichocarpa plants exhibited marked elevations at the 12 h mark following exposure to MeJA. Notably, the magnitude of this increase was more pronounced in the overexpressed plants compared to their wild-type counterparts [ 127 ]. After 6 h of SA treatment, the transcription level of ShMAPK5 in Saccharumofficinarum was upregulated [ 128 ].…”