Journal of Tea Science Research, 2024, Vol.14, No.4, 192-201 http://hortherbpublisher.com/index.php/jtsr 194 Figure 1 Induced systemic resistance (ISR) by beneficial microorganisms (Adopted from Ebrahimi-Zarandi et al., 2022) Image caption: JA and ET are central regulators phytohormones of ISR, and transcription factors (e.g., MYC2) mediate the increased responsiveness of this pathway to stimulation, known as priming. Transcription factor MYB72, as a root-specific transcription factor and early signaling factor, functions as a node of convergence in ISR elicited by beneficial microbes. (ET, ethylene; JA, jasmonic acid; NPR1, NONEXPRESSOR OF PR GENES1; MAMPs, microbe-associated molecular patterns; PRRs, plant recognition receptors; PTI, PAMP-triggered immunity; TFs, transcription factors) (Adopted from Ebrahimi-Zarandi et al., 2022) Ebrahimi-Zarandi et al. (2022) found that induced systemic resistance (ISR) is a crucial defense mechanism in plants activated by beneficial microorganisms in the rhizosphere. This process is regulated primarily by the phytohormones jasmonic acid (JA) and ethylene (ET), which enhance the plant's defensive capabilities. The root-specific transcription factor MYB72 plays a pivotal role in early ISR signaling, serving as a convergence point for signals from beneficial microbes. Additionally, ISR involves the pattern triggered immunity (PTI) pathway, which is mediated by plant recognition receptors (PRRs) detecting microbe-associated molecular patterns (MAMPs). Key transcription factors such as MYC2 further prime the plant's defense genes for enhanced responsiveness. This priming effect ensures that upon subsequent attacks, the plant's defense response is more robust and effective, contributing to an overall improved resilience against pathogens. 3.2 Induced systemic resistance in plants Induced systemic resistance (ISR) is a plant defense mechanism activated by beneficial microbes, leading to enhanced resistance against a broad spectrum of pathogens and pests. ISR involves long-distance systemic signaling within the plant, often mediated by jasmonic acid (JA) and ethylene (ET) pathways, although salicylic acid (SA) can also play a role (Yu et al., 2022). Beneficial microbes trigger ISR, priming the plant's immune system for rapid and robust responses to pathogen invasions. This mechanism has been extensively studied in various crops, including tea, where microbial pesticides have been employed to counteract mite and insect pest damage. The activation of ISR by beneficial microbes not only enhances plant immunity but also contributes to sustainable pest management practices by reducing reliance on chemical pesticides (Zehra et al., 2021). 3.3 Direct parasitism and predation Direct parasitism and predation by beneficial microbes are effective biological control strategies against tea pests. Entomopathogenic microorganisms (EM), such as fungi, nematodes, viruses, and bacteria, directly infect and kill insect pests, providing a natural and eco-friendly alternative to chemical pesticides (Deka et al., 2022). The efficiency of entomopathogenic microorganisms against various tea pests has been demonstrated, with microbial biopesticides showing promising effects in controlling pest populations (Deka and Babu, 2021). Additionally, the role of microorganisms in indirect pest biological control, such as enhancing plant defense responses and
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