# Parasitic Plant–Host Interactions: Molecular Mechanisms and Agricultural Resistance Strategies

## TL;DR

This paper reviews how parasitic plants interact with crops at a molecular level and explores strategies to develop resistant crops for sustainable agriculture.

## Contribution

The paper integrates recent molecular insights with agricultural strategies to combat parasitic plants, emphasizing CRISPR and host immunity.

## Key findings

- Parasitic plants use strigolactones and chemotropic signals for germination and host attachment.
- Host plants use multi-tier defenses like lignin deposition and hormone-coordinated immunity.
- CRISPR and genomic approaches offer new ways to engineer crop resistance.

## Abstract

Obligate parasitic plants, particularly members of the Orobanchaceae family, including Striga and Orobanche, greatly devastate crop production. Here, we synthesize recent advances in understanding the molecular and ecological dynamics underlying parasitic plant‐host interactions, focusing on critical stages of parasitism: germination, host detection, haustorium formation, and resource extraction. Orobanchaceous parasites exploit host‐derived strigolactones (SLs) to break seed dormancy, whereas Cuscuta species do not rely on SLs for germination. Instead, chemotropic responses to host‐exuded compounds and light signals guide the directional growth of their seedlings. Haustorium morphogenesis, initiated through host lignin‐derived quinones and redox‐sensitive compounds, establishes vascular connectivity enabling nutrient diversion. Meanwhile, host organisms employ sophisticated multi‐tier defense strategies encompassing SL biosynthesis, lignin deposition enhancement, hypersensitive cellular responses, and hormone‐coordinated immunity. Key discoveries, such as receptor kinases and horizontal gene transfer events, highlight evolutionary arms races between parasites and hosts. Emerging technologies like CRISPR offer promising avenues for engineering resistant crops by disrupting parasitic signaling or enhancing host immunity. This review underscores the importance of integrating molecular insights with agricultural innovation to mitigate yield losses and addresses future challenges, including climate‐driven parasite spread and the need for sustainable, genomics‐driven solutions. By deciphering the silent dialogue between parasites and hosts, this work provides foundations for transformative strategies to safeguard global food security.

Parasitic plants devastate global agriculture through sophisticated molecular interactions with host crops. This review synthesizes current understanding of parasitic plant‐host interactions, from strigolactone‐mediated germination and haustorium formation to host defense mechanisms. We discuss integrated resistance strategies combining genetic engineering, chemical interventions, and ecological management, addressing critical knowledge gaps to advance sustainable control of these agricultural threats.