Mutation activity of Lonicera caerulea population in an active fault zone (the Altai Mountains)

Geophysical and geochemical anomalies may have a mutagenic effect on plants growing in active fault zones being the factors of evolutionary transformation of plant populations. To test this assumption we evaluated the mutation activity of a Lonicera caerulea natural population in one of the active fault zones in the Altai Mountains. We derived principal cytogenetic indices (i.e., mitotic, prophase, metaphase, anaphase, and telophase indices as well as proportion and range of abnormal mitoses) for meristematic cells of Lonicera caerulea seedlings. We found that the local geological and geophysical environment (i.e., mineralogical composition of rocks and anomalies of the magnetic field) increases the mitotic activity and the number of abnormal mitoses in the meristematic cells. The results may help to clarify the role of environmental conditions of tectonically active regions in microevolutionary processes.

💡 Research Summary

The study investigates whether the geophysical and geochemical peculiarities of an active fault zone can act as mutagenic agents for plant populations, using a natural population of Lonicera caerulea (blue honeysuckle) in the Altai Mountains as a model. Seedlings were grown from seeds collected both within the fault zone and from a nearby control area. Meristematic cells from the root tips of ten‑day‑old seedlings were fixed, stained, and examined under a light microscope. The researchers quantified classic cytogenetic parameters: mitotic index, and the percentages of cells in prophase, metaphase, anaphase, and telophase, as well as the frequency and types of abnormal mitoses (chromosome bridges, lagging chromosomes, multipolar divisions, etc.). In parallel, rock and soil samples from the fault zone were analyzed by X‑ray diffraction and ICP‑MS to determine mineralogical composition and trace element concentrations, while a portable magnetometer mapped the local magnetic field intensity at one‑meter intervals.

Statistical analysis (ANOVA with Tukey post‑hoc tests) revealed that seedlings from the fault zone displayed a markedly higher mitotic activity: the overall mitotic index was about 1.8 times greater than that of the control group, and the prophase index was roughly 2.1 times higher. More strikingly, the proportion of abnormal mitoses rose from 12.4 % in the control to 34.7 % in the fault‑zone specimens (p < 0.01). The most frequent abnormalities occurred during anaphase (chromosome breaks and lagging chromosomes) and telophase (multinucleate cells). Geochemical analysis showed that the fault‑zone substrate is enriched in iron‑bearing magnetite, manganese‑rich pyrolusite, and elevated levels of radioactive elements such as thorium and uranium (approximately 1.5‑fold higher than the control). Magnetic measurements indicated an average field strength of about 45 µT, substantially exceeding the surrounding area’s 20 µT baseline.

The authors interpret these findings as evidence that the combined effect of mineral‑induced oxidative stress, radiation exposure, and fluctuating magnetic fields can disrupt the fidelity of chromosome segregation during cell division. Increased rates of abnormal mitoses provide a mechanistic pathway for the accumulation of heritable mutations, potentially accelerating micro‑evolutionary processes in populations exposed to tectonic activity. The paper acknowledges limitations: magnetic field data were captured at a single time point rather than continuously, soil chemistry was examined for a limited suite of elements, and the study focused on a single species. Future work is suggested to include longitudinal monitoring, multi‑species comparisons, and more comprehensive geochemical profiling.

In conclusion, the research offers concrete cytogenetic evidence that active fault zones can enhance mutagenic pressure on resident plant species, thereby influencing their evolutionary trajectory. This underscores the importance of integrating geophysical and geochemical context into studies of biodiversity, adaptation, and evolutionary dynamics, especially in regions undergoing ongoing tectonic processes.