How jujube enhances defense against phytoplasma through lignin biosynthesis

A research team has uncovered a significant regulatory mechanism that enhances the jujube tree's defense against phytoplasma infections. By focusing on lignin biosynthesis, the study highlights how the ZjMYB44-ZjPOD51 module upregulates lignin production, crucial for reinforcing plant defenses. The findings open doors for improving jujube resistance breeding by leveraging this defense pathway. This novel insight not only contributes to our understanding of plant defense mechanisms but also offers potential strategies for managing phytoplasma-induced diseases in crops.

Phytoplasma infections severely affect many plants, including jujube, causing disease symptoms like witches' broom. Lignin, a crucial component of plant cell walls, plays a significant role in plant defense by strengthening the cell structure and acting as a barrier against pathogen invasion. However, the molecular pathways behind lignin regulation in response to phytoplasma stress remained unclear until now. Based on these challenges, further research into the regulation of lignin biosynthesis and its impact on phytoplasma resistance is needed to develop effective control strategies for jujube.

In a recent study published (DOI: 10.1093/hr/uhaf083) in Horticulture Research, researchers from Hebei Agricultural University and the Chinese Academy of Sciences, led by Dr. Jin Zhao, identified how the ZjMYB44-ZjPOD51 transcriptional module enhances lignin biosynthesis in jujube. The findings shed light on the molecular regulation of plant defense in response to phytoplasma infection, offering new strategies for disease resistance breeding.

This study explores the role of the ZjMYB44-ZjPOD51 module in enhancing jujube's defense response against phytoplasma. The team discovered that the expression of ZjMYB44, a transcription factor, is induced by phytoplasma infection, activating ZjPOD51, a peroxidase enzyme involved in lignin biosynthesis. The overexpression of ZjPOD51 led to increased lignin content, improving the plant's ability to combat phytoplasma. This was further validated through experiments in both jujube and Arabidopsis plants, where ZjPOD51 overexpression resulted in significantly enhanced defense responses, reduced phytoplasma content, and upregulated defense-related genes.

"These findings represent a major step in understanding how plants regulate their defense mechanisms at the molecular level," said Dr. Jin Zhao, the lead researcher of the study. "By unraveling the role of lignin biosynthesis in phytoplasma resistance, we can now explore targeted breeding strategies to enhance disease resistance in jujube and potentially other crops."

This research not only advances our understanding of plant defense mechanisms but also has important implications for agricultural practices. By targeting the ZjMYB44-ZjPOD51 pathway, future breeding programs could develop jujube varieties with improved resistance to phytoplasma, helping to mitigate the economic losses caused by this destructive disease. Additionally, the findings could inform similar efforts in other crops affected by phytoplasma and related pathogens, contributing to more resilient agricultural systems.

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References

DOI

10.1093/hr/uhaf083

Original Source URL

https://doi.org/10.1093/hr/uhaf083

Funding information

This work was supported by grants from the Central Guidance for Local Science and Technology Development Funds Project (236Z6801G), the Natural Science Foundation of Hebei Province (C2024204185), the National Natural Science Foundation of China (32471909), and the Hebei Province Innovation Foundation for Postgraduates (CXZZBS2022053).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.