Plant iron acquisition strategy exploited by an insect herbivore

Area of Science:

• Plant-insect interactions
• Plant biochemistry
• Nutrient uptake mechanisms

Background:

• Insect herbivores rely on host plants for essential nutrients.
• Maize plants produce benzoxazinoids for defense and iron uptake.
• The western corn rootworm is a significant maize pest.

Purpose of the Study:

• To investigate how the western corn rootworm locates and utilizes micronutrients from maize.
• To understand the role of benzoxazinoid-iron complexes in this interaction.

Main Methods:

• Analysis of rootworm feeding behavior.
• Identification of iron transporters in western corn rootworm.
• Biochemical analysis of maize root exudates.

Main Results:

• Western corn rootworm larvae utilize iron-benzoxazinoid complexes to identify maize as a host.
• These complexes facilitate rootworm foraging and growth.
• An iron transporter in the rootworm enables exploitation of these complexes.
• Benzoxazinoids serve dual roles in plant defense and iron acquisition.

Conclusions:

• Plant secondary metabolites and micronutrient availability significantly influence specialist herbivore foraging strategies.
• The interaction between maize and western corn rootworm is shaped by the exploitation of iron-benzoxazinoid complexes.
• This study reveals a novel mechanism of nutrient acquisition in insect herbivores.