Abstract
Heavy metal pollution severely impacts plant health by inhibiting growth, photosynthesis, enzyme activities, and causing oxidative stress. Plants respond to such stress by activating complex defense mechanisms involving reactive oxygen species and different signaling pathways. These pathways are pivotal in triggering plant defense responses and are currently a major focus of research. Understanding the complex mechanisms of heavy metal uptake, transport, chelation, and signaling can guide strategies to improve plant resilience and stress tolerance. In this review, we aim to highlight the key heavy metals found in soil and the environment, along with their mechanisms of accumulation in plants. We also explore the defense responses of plants through various signaling pathways such as calcium (Ca(2+)), MAP kinase, and hormone signaling. Additionally, we emphasize the importance of understanding advanced omics technologies, including transcriptomics, metabolomics, and bioinformatic tools, in enhancing our knowledge of plant resilience and stress tolerance.