Chitinase AbChi1 acts with the carbohydrate-binding module AbCbm1 to regulate mycelial growth in Agaricus bisporus

Area of Science:

• Mycology
• Molecular Biology
• Biochemistry

Background:

• Chitinase plays a crucial role in regulating mycelial growth and development in Agaricus bisporus.
• Understanding the specific genes and their interactions involved in this process is essential for mushroom cultivation.

Purpose of the Study:

• To clone and characterize the chitinase gene (AbChi1) and its interacting carbohydrate-binding module gene (AbCbm1) in Agaricus bisporus.
• To elucidate the functional roles of AbChi1 and AbCbm1 in regulating mycelial growth and development.

Main Methods:

• Gene cloning and screening via pre-transcriptomics.
• Yeast two-hybrid and GST-pull down assays for protein interaction analysis.
• Gene silencing (RNAi) and overexpression techniques to study gene function.
• Scanning electron microscopy for analyzing mycelial morphology.

Main Results:

• Overexpression of AbChi1 and AbCbm1 significantly reduced the growth rate of Agaricus bisporus.
• Chitin content was decreased in strains overexpressing AbChi1 and AbCbm1 compared to wild-type and RNAi strains.
• Scanning electron microscopy confirmed reduced mycelial density and cross-sectional area in overexpression strains.
• Direct interaction between AbChi1 and AbCbm1 was confirmed.

Conclusions:

• Both AbChi1 and AbCbm1 play significant roles in regulating mycelial growth in Agaricus bisporus.
• Overexpression of these genes leads to delayed mycelial growth, providing a potential mechanism for growth control.
• The confirmed interaction between AbChi1 and AbCbm1 offers a deeper understanding of chitin metabolism and growth regulation in this species.