Related Experiment Video

Updated: Feb 24, 2026

A Hydroponic Co-cultivation System for Simultaneous and Systematic Analysis of Plant/Microbe Molecular Interactions and Signaling
11:16

A Hydroponic Co-cultivation System for Simultaneous and Systematic Analysis of Plant/Microbe Molecular Interactions and Signaling

Published on: July 22, 2017

14.8K

The adenylate cyclase-mediated signaling pathway required for regulating siderophore and toxin biosynthesis and

Kai-Chu Huang1,2, Hsin-Yu Lu1,2, Celine Yen Ling Choo3

  • 1Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, Taiwan.

Frontiers in Fungal Biology
|February 23, 2026
PubMed

Insights

The adenylate cyclase (AaAC) in fungal pathogen A. alternata is crucial for iron uptake and virulence. Its absence impairs siderophore production and toxin biosynthesis, highlighting AaAC's role in fungal pathogenicity.

Area of Science:

  • Mycology
  • Molecular Biology
  • Plant Pathology

Background:

  • Cyclic AMP-protein kinase A (PKA) signaling's role in siderophore-mediated iron uptake and virulence in phytopathogenic fungi is unclear.
  • The Adenylate Cyclase (AaAC) in Alternaria alternata (A. alternata) influences growth, conidiation, iron homeostasis, autophagy, siderophore biosynthesis, and toxin production.

Purpose of the Study:

  • To investigate the role of AaAC in regulating iron homeostasis, siderophore biosynthesis, and virulence in A. alternata.
  • To elucidate the signaling pathway involving AaAC, Gα, and PKA in response to environmental cues.

Main Methods:

  • Genetic studies involving deletion mutants of AaAC, Gα, PKA catalytic, and regulatory subunits.
  • Transcriptomic analysis under iron-deficient conditions.
  • Gene ontology analysis.

Main Results:

  • Deletion of AaAC impaired siderophore secretion, disrupted iron-responsive gene expression, and abolished ACT toxin production, significantly reducing virulence.
  • AaAC deletion led to widespread gene expression changes, particularly downregulation of siderophore biosynthesis and ACT toxin production genes.
  • Environmental signals for siderophore biosynthesis appear to be transmitted via a Gα-AaAC-PKA cascade. AaAC also negatively regulates autophagy under nutrient-rich conditions.

Conclusions:

  • AaAC is a key regulator of metabolic pathways essential for A. alternata survival and pathogenicity.
  • AaAC integrates environmental signals to maintain iron homeostasis, control toxin production, and drive fungal virulence.
  • AaAC plays a vital role in cellular energy preservation and physiological stability through its regulation of autophagy.
Keywords:
ACT toxinadenylate cyclaseautophagycAMPsiderophores

More Related Videos

Bacterial Leaf Infiltration Assay for Fine Characterization of Plant Defense Responses using the Arabidopsis thaliana-Pseudomonas syringae Pathosystem11:50

Bacterial Leaf Infiltration Assay for Fine Characterization of Plant Defense Responses using the Arabidopsis thaliana-Pseudomonas syringae Pathosystem

Published on: October 1, 2015

22.9K
Pattern-Triggered Oxidative Burst and Seedling Growth Inhibition Assays in Arabidopsis thaliana04:11

Pattern-Triggered Oxidative Burst and Seedling Growth Inhibition Assays in Arabidopsis thaliana

Published on: May 21, 2019

14.1K

Related Concept Videos

Intracellular Signaling Cascades01:24

Intracellular Signaling Cascades

Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the...
53.9K
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
7.7K
Global Regulatory Systems01:28

Global Regulatory Systems

Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
775
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
755
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
7.4K
Cell Signaling in Plants01:25

Cell Signaling in Plants

Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
6.7K