Rice University Researchers Identify PEX11 Protein as Critical Regulator for Early Plant Development and Energy Processing

Rice University researchers discover how the PEX11 protein regulates peroxisome size and energy use in seedlings. Learn more about this cellular breakthrough.

By: AXL Media

Published: Apr 25, 2026, 11:13 AM EDT

Source: Information for this report was sourced from EurekAlert

A Molecular Bridge Between Seed Germination and Solar Energy

The early stages of a plant's life represent a high stakes metabolic transition where survival depends on internal energy reserves. Before a seedling develops the capacity for photosynthesis, it must extract energy from stored fatty acids to fuel its rapid growth. Research led by Bonnie Bartel at Rice University has pinpointed the peroxisome, a specialized membrane bound compartment, as the engine of this process. The study, published in Nature Communications, reveals that the peroxisome undergoes a dramatic physical expansion during the seed to seedling stage to accommodate this demand. This biological growth spurt is not random, rather, it is governed by a specific protein that ensures the cell’s internal machinery remains efficient and manageable.

Utilizing CRISPR to Decode Complex Genetic Redundancy

Investigating the PEX11 protein required overcoming a significant genetic hurdle, as the Arabidopsis plants used in the study possess five different genes that code for the protein. According to Nathan Tharp, a Rice graduate student and the study’s first author, breaking a single gene resulted in no observable change, while disabling all five proved fatal to the plant. To isolate the protein’s specific function, Tharp utilized recent advancements in CRISPR gene editing to disable precise combinations of these genes. This targeted approach allowed the team to observe for the first time how PEX11 directly influences the physical dimensions and structural integrity of the peroxisome during the plant's most vulnerable developmental window.

The Consequences of Unchecked Peroxisome Expansion

The research team created two specific mutants to observe the effects of a disabled PEX11 system. In these modified plants, the peroxisomes displayed a startling lack of regulation, growing so large that they spanned the entire distance between the top and bottom of the cell. Under normal conditions, these compartments should shrink back to a standard size once the plant begins harnessing sunlight. However, in the absence of functional PEX11, the growth continued unchecked. This finding suggests that PEX11 acts as a metabolic governor, preventing cellular structures from expanding to a point where they might interfere with other vital biological functions within the plant cell.