The central argument is deceptively simple but has far-reaching consequences for conservation. Genetic variability is a key factor in resilience, yet the way it is spread across populations matters as much as its total amount. Population differentiation reflects the cumulative effects of demographic history, geographic separation, gene flow and natural selection, and locally adapted groups may carry variants that confer advantages under specific climatic or soil conditions. A species can appear genetically rich on paper while lacking the particular alleles needed to tolerate the hotter, drier or saltier environments it is projected to face. Conversely, a geographically restricted population might hold distinct adaptive variants that are disproportionately valuable for the species’ future. Conservation that focuses only on neutral diversity or on headcounts of populations may therefore fail to preserve exactly the variation that matters most.

The evidence for this pattern comes from a series of case studies across taxonomically unrelated genera. The endangered Chinese medicinal plant Coptis chinensis var. brevisepala shows low anticipated heterozygosity, measured at He = 0.067, and pronounced genetic differentiation, with FST = 0.503, driven mainly by geographic isolation. Isodon rubescens, by contrast, was found to comprise two genetic clusters with 456 adaptive single nucleotide polymorphisms linked to environmental variation, with precipitation identified as a significant driver. Apocynum venetum demonstrated considerable diversity in its Xinjiang population in connection with saline–alkali adaptation, while Saussurea obvallata displayed low diversity with a decline from east to west linked to geographic distance. The review’s authors are careful to note that these cross-species convergences support isolation-driven structuring as a general feature of medicinal-plant populations, but that the specific environmental driver identified in each case rests on a single study and should be read as illustrative rather than generalizable until replicated.

Whole-genome resequencing of the Rheum palmatum complex adds a demographic dimension to this picture. The analysis revealed differing adaptive capabilities between western and eastern lineages, with thousands of pan-adaptive sites concentrated in the western lineage and pronounced genomic drift in the eastern lineage. In practical terms, two lineages of the same species complex can carry very different evolutionary portfolios, one rich in variants associated with long-term climate adaptation and the other shaped more by random fluctuations in allele frequencies. For conservation planners, this means that protecting a species somewhere is not the same as protecting the adaptive variation it needs everywhere. Meanwhile, the Aconitum genus illustrates the opposite problem: a group with significant conservation concerns for which genomic and metagenomic data remain scarce, leaving its adaptive capacity essentially unassessable with current resources.

Landscape genomics offers the analytical bridge between these population-genetic patterns and the environmental gradients that drive them. By testing whether variation in allele frequencies correlates with climate, soil or other environmental factors, researchers can pinpoint genomic regions linked to specific selective pressures. In Tetrastigma hemsleyanum, winter rainfall was the most significant predictor of genetic structure, with 275 candidate adaptive SNPs associated with flowering timing and abiotic stress management. In Apocynum venetum, saline–alkali environments were linked to adaptive loci including a flavonol 4′-sulfotransferase gene, while ultraviolet light and low temperature may play roles in finer-scale adaptation in Coptis chinensis var. brevisepala. These genotype–environment associations allow conservationists to move beyond ranking populations by neutral diversity and instead identify genomic vulnerability: the gap between the alleles a population currently holds and the alleles it will need under anticipated climates.

The review is emphatic, however, that genomic vulnerability is not a definitive forecast of extinction. A statistically significant association between genotype and environment indicates correlation, not confirmed adaptation. Candidate loci require functional and ecological verification, and adaptive potential is shaped by gene flow, existing variation, phenotypic plasticity, population growth and biotic interactions. Predictions are also sensitive to sampling design and to whether the environmental variables included in association models genuinely reflect the selective environment a population experiences. A population might maintain substantial genome-wide diversity yet lack alleles tied to future conditions, or a small population might carry unique adaptive variants of high conservation value. Only when adaptive genomic signals, environmental exposure, demographic sustainability and ecological effectiveness align does the evidence support the strongest conservation inferences.

Genetic adaptation, the authors stress, operates alongside a second layer of resilience: phenotypic plasticity. Transcriptomic and metabolomic analyses show that medicinal plants can rapidly adjust osmotic regulation, antioxidant defense, hormone signaling, cell-wall metabolism and specialized metabolite production in response to drought, salinity and heat stress. In Eugenia uniflora, populations exposed to drought exhibited changes in expression related to osmoprotection, cell-wall alteration, detoxification and epigenetic regulation, with glycosyltransferase genes linked to drought responses. Rosemary, Tinospora cordifolia, Atractylodes lancea and Arnebia guttata provide further examples connecting environmental stress to antioxidant, terpenoid, flavonoid and alkaloid pathways. Secondary metabolites occupy a special position in this picture because they can function both as compounds that protect plants against stress and as the pharmacologically valuable products for which these species are harvested in the first place, with water supply, temperature, light and soil composition all influencing their accumulation.

Epigenetic mechanisms add yet another level of rapid response. DNA methylation, histone modifications and small-RNA pathways can alter transcription without changing the DNA sequence, potentially enabling plastic adjustments when environmental change outpaces the rate at which allele frequencies can shift. Direct evidence from medicinal plants remains scarce, but Scrophularia ningpoensis stands out as one of the few cases demonstrated directly within a medicinal plant, where climate change influenced H3K36me3-related regulation of iridoid production. Much of the broader mechanistic detail comes from model species: in Arabidopsis, which is not used medicinally, the HDA9–PWR–ABI4 complex inhibits CYP707A genes needed for abscisic acid breakdown, thereby aiding ABA accumulation during drought. The authors caution that such mechanisms should be regarded as representations of potential regulatory frameworks rather than direct proof that HDA9 governs medicinal-plant adaptation in the wild, and that research directly testing HDA9 function in non-model medicinal plants is a significant gap. Notably, in Saussurea obvallata, metabolic differences between populations correlated with temperature variables even though genetic diversity accounted for minimal metabolic variation, underscoring the need to distinguish genetic diversity, adaptive genomic variation and environmentally induced chemical plasticity in conservation assessments.

These findings translate into a portfolio of genomics-informed conservation strategies. Gene Conservation Units can prioritize populations with distinctive evolutionary variation, provided they incorporate adaptive as well as neutral diversity. Assisted migration can move climate-adapted material to suitable future habitats where natural range shifts are too slow or fragmented, though risk assessment and provenance matching are essential, since moving genotypes between environments can cause maladaptation or disrupt local gene pools. Evolutionary plant breeding maintains genetic heterogeneity in cultivated medicinal species rather than selecting narrowly uniform genotypes. Temporal genomics, tracking allele-frequency change through repeated or historical sampling, is emerging as a tool for monitoring climate responses, while ex situ conservation and gene banking remain essential for highly vulnerable species. The authors insist these approaches must complement, not replace, sustainable harvesting, habitat restoration and habitat protection.

The research gaps the review identifies are ordered by urgency. The most immediate need is broader geographic and taxonomic sampling, because genomic resources remain concentrated on a few economically significant or model organisms and many existing studies are geographically restricted, limiting the ability to distinguish local adaptation from demographic history or isolation by distance. A second, equally urgent priority is functional validation of candidate adaptive loci, which will require common-garden and reciprocal-transplant experiments testing whether genomic variants translate into measurable fitness benefits under field conditions. Third comes temporal genomics to determine whether populations respond consistently to recurrent climatic stress rather than short-term fluctuations. Ecological interactions such as pollination, pathogens, competitors and selective harvesting are seldom incorporated into genomic vulnerability assessments and warrant systematic inclusion. Finally, the authors argue, genomic findings must be integrated directly into conservation management: instead of compiling extensive candidate-gene lists, research should identify which populations require protection, which habitats must remain connected and which genetic resources should be conserved ex situ, converting conservation genomics from a descriptive exercise into an actionable component of medicinal-plant management.

Subject of Research: Evolutionary genomics and conservation of medicinal plants under climate change

Article Title: Medicinal plants in a changing climate: evolutionary genomics for resilience and conservation

Article References: Sarkar, I., Das, P., Chattopadhyay, D., & Nath, U. K. (2026). Medicinal plants in a changing climate: evolutionary genomics for resilience and conservation. Frontiers in Ecology and Evolution, 14, 1983830. https://doi.org/10.3389/fevo.2026.1983830

Image Credits: AI Generated

DOI: 10.3389/fevo.2026.1983830

Keywords: medicinal plants, climate change, landscape genomics, genetic diversity, genomic vulnerability, local adaptation, epigenetics, phenotypic plasticity, conservation genomics, assisted migration, specialized metabolism, habitat fragmentation