ERdj3B-Mediated Quality Control Maintains Anther Development at High Temperatures

Area of Science:

• Plant Biology
• Molecular Biology
• Stress Physiology

Background:

• Pollen development is sensitive to heat stress, leading to protein misfolding and impaired cellular proteostasis.
• The endoplasmic reticulum (ER) employs a quality control system with molecular chaperones, including BiP and J proteins, to manage protein folding.
• ER-resident J proteins are key cochaperones in the ER quality control machinery.

Purpose of the Study:

• To investigate the role of ERdj3B, an ER-resident J protein, in Arabidopsis anther development and fertility under heat stress.
• To determine if ERdj3B function is essential for plant reproduction under elevated temperatures.
• To elucidate the specific interactions and functional differences of ERdj3B within the ER quality control system.

Main Methods:

• Generating and characterizing Arabidopsis mutants of ERdj3B.
• Assessing fertility and seed production under normal and high-temperature conditions (29°C).
• Analyzing anther and pollen development using microscopy and RNA sequencing.

Main Results:

• Arabidopsis mutants lacking ERdj3B exhibited temperature-sensitive infertility at high temperatures due to defective anther development.
• The fertility defect was linked to specific impaired interactions between BiP and ERdj3B.
• RNA sequencing revealed heightened susceptibility of the erdj3b mutant to heat stress during pollen development, suggesting compromised ER quality control.

Conclusions:

• ERdj3B plays a critical role in plant reproduction, particularly in anther development, under high-temperature stress.
• ERdj3B's function is distinct from other ER-resident J proteins, highlighting specialized roles in ER quality control.
• Targeting ERdj3B may offer strategies to enhance plant resilience to heat stress and ensure crop yield.