# Molecular mechanisms and breeding strategies for heat tolerance in vegetable crops under global warming

## TL;DR

This paper reviews how extreme heat affects vegetable crops and proposes breeding strategies to develop heat-tolerant varieties for food security under climate change.

## Contribution

The paper introduces six strategic pathways for breeding heat-resilient vegetables based on molecular mechanisms and interdisciplinary approaches.

## Key findings

- Heat stress disrupts vegetable development from germination to reproduction, causing morphological and physiological impairments.
- Molecular mechanisms like HSFs, HSPs, and Ca2+-ROS signaling contribute to thermotolerance in vegetables.
- Strategies such as CRISPR editing, epigenetic memory, and synthetic promoters are proposed to enhance heat resilience.

## Abstract

Extreme heat driven by climate change poses a catastrophic threat to global vegetable production, undermining nutritional security because of the heightened physiological sensitivity and succulent tissues of these crops. This review synthesizes the multistage impacts of heat stress across critical developmental phases—from germination to reproduction—emphasizing morphological impairments (such as leaf wilting and floral abortion) and physiological disruptions (including photosynthetic inhibition and oxidative damage). We systematically dissect thermotolerance mechanisms in vegetables, highlighting transcriptional reprogramming by HSFs, WRKY, and NAC transcription factors; chaperone-mediated proteostasis via HSPs; epigenetic remodeling; Ca2+-ROS signaling pathways; and the role of phase separation dynamics. Importantly, we propose six strategic pathways to develop heat-resilient vegetables: harnessing natural variation through pan-genome-driven allele mining; employing biotechnological interventions such as CRISPR-mediated editing and synthetic promoters; engineering multistress tolerance by targeting conserved ‘core response’ pathways; exploiting epigenetic memory to achieve transgenerational resilience; optimizing source-sink dynamics with ‘’Climate-Responsive Carbon Optimization; and applying plant growth regulators and nanotechnology to enhance thermotolerance. Together, these strategies chart a clear roadmap for climate-smart vegetable breeding and call for interdisciplinary collaboration to translate molecular discoveries into practical breeding approaches for sustainable food systems under escalating thermal extremes.