Plant-PATH researcher Lukas Schulz publishes review on how herbicides hijack auxin transport

In the review, “Hijacking the auxin highway: Substrate Recognition of Phenoxyacetic Acid Herbicides,” Lukas and his co-authors, including four other Plant-PATH members, bring together structural, biochemical and physiological evidence to explore how synthetic auxin herbicides exploit the plant’s own hormone transport machinery.

Phenoxyacetic acid herbicides have been used for decades, and their effects are closely linked to the plant hormone auxin. The review highlights how these compounds can be recognised and transported by key auxin transport proteins, including AUX/LAX importers and PIN exporters, in ways that resemble the transport of the natural auxin indole-3-acetic acid (IAA).

The authors discuss how the molecular recognition of these compounds depends on conserved interactions with their carboxyl group, while interactions with their aromatic moiety, including the effects of halogen substitutions, influence their affinity and specificity. The review also considers why these herbicides have relatively limited mobility within plants, pointing to processes such as intracellular sequestration, metabolism and conjugation.

Understanding how synthetic auxins interact with the plant’s transport machinery is particularly relevant for understanding herbicide activity and resistance. The review brings together current evidence suggesting that changes in transport and metabolism are important mechanisms underlying resistance to synthetic auxins.

The publication reflects Plant-PATH’s interest in understanding the molecular mechanisms that govern the active transport of plant hormones, and highlights how knowledge of hormone transporter structure and function can also help explain how plants respond to compounds that interfere with these systems.

Congratulations to Lukas on this publication!

Read the full article: https://doi.org/10.1093/jxb/erag404