The meiotic achilles' heel: vulnerability and resilience under environmental stress.

Plant meiosis constitutes a critical vulnerability under unfavorable conditions in plant reproduction. In the 21st century, with the accelerating global climate change, environmental stresses increasingly compromise fertility and genetic stability. This review examines the role of abiotic stress factors - including heat, cold, drought, salinity, heavy metals, and oxidative stress - in disruption of plant meiosis, the achilles' heel of sexual processes. Heat stress appears particularly damaging, by compromising several molecular functions, such as DNA double-strand break formation, chromosome axis formation and spindle assembly. Cold stress affects meiotic recombination patterns as well as induces cytoskeletal disruption leading to unreduced gamete formation. While drought primarily impacts post-meiotic pollen development rather than meiosis itself, heavy metals cause widespread chromosomal abnormalities, generating reactive oxygen species and chromatin architectural alterations. In these stress responses, oxidative damage appears as a convergent pathway, yet paradoxically, controlled ROS production remains essential for normal meiotic progression. Critically, meiotic vulnerability is not merely an evolutionary oversight but potentially an adaptive feature. Stress-induced increasing recombination rate elevates genetic diversity, while weak checkpoints permit aneuploidy and unreduced gamete formation, thus facilitate polyploidization, a primary driver of plant speciation.