Soybean transporter AAT Rhg1 abundance increases along the nematode migration path and impacts vesiculation and ROS

Area of Science:

• Plant pathology
• Molecular genetics
• Biochemistry

Background:

• The Rhg1 locus controls soybean resistance to soybean cyst nematode (SCN).
• The Rhg1-GmAAT gene encodes a putative amino acid transporter involved in SCN resistance.
• The precise mechanism of AATRhg1 in plant defense remains largely uncharacterized.

Purpose of the Study:

• To elucidate the function and mechanism of AATRhg1 in soybean's defense against SCN.
• To investigate the spatial and temporal distribution of AATRhg1 during SCN infection.
• To determine the role of AATRhg1 in ROS production and plant immunity.

Main Methods:

• Immunolocalization of AATRhg1 protein in soybean roots during SCN infection.
• Co-expression studies in Nicotiana benthamiana to assess AATRhg1 interactions and ROS generation.
• Analysis of vesicle formation and AATRhg1 localization within root cells.

Main Results:

• AATRhg1 protein abundance significantly increased in soybean root cells along the SCN migration path.
• AATRhg1 was localized to vesicles and vesicle-like bodies within these cells.
• AATRhg1 interacted with GmRBOHG and stimulated ROS production, particularly under oxidative stress.
• AATRhg1 abundance was low in SCN-induced syncytia, contrasting with other Rhg1 proteins.

Conclusions:

• AATRhg1 contributes to SCN resistance by increasing ROS production in root cells during nematode invasion.
• Different Rhg1 resistance proteins may employ distinct mechanisms and operate at different times/locations to confer immunity.
• This study reveals a novel role for AATRhg1 in plant defense signaling pathways.