Temperature-Associated Anatomical, Photosynthetic, and Putative GC–MS Metabolomic Profiles in the Arid Species Nitraria sibirica Pall. and Nitraria schoberi L.

Backgrounds: The present study investigated temperature-associated responses of microclones of two halophytic shrubs, Nitraria sibirica Pall. and Nitraria schoberi L., exposed to low positive (+3 °C) and elevated (+30 °C) temperatures for 72 h. Methods: Temperature-associated responses were investigated by evaluation of leaf anatomy, chlorophyll fluorescence, and GC–MS-based metabolite profiling. Results: The results revealed shared and species-specific responses, including changes in leaf anatomical dimensions, maintenance or adjustment of PSII-related fluorescence parameters, and treatment-dependent shifts in the relative composition and diversity of putatively annotated metabolite classes. Metabolomic profiling was performed in both in vitro microclones and soil-acclimatised microclones. In vitro microclones showed more pronounced shifts in the number and relative representation of detected compound classes under temperature exposure, whereas soil-acclimatised microclones demonstrated comparatively greater compositional stability. Comparative analysis of the datasets revealed temperature-associated patterns across anatomical, photosynthetic, and relative metabolomic responses; however, these patterns were interpreted descriptively rather than as direct causal mechanisms. Some detected compounds or compound classes have been associated with biological relevance in previous studies; however, their identity, abundance, and activity require targeted validation. Conclusions: Overall, the findings provide a descriptive experimental dataset on temperature-associated anatomical, chlorophyll fluorescence, and relative GC–MS profile changes in Nitraria microclones and identify candidate metabolite classes for future targeted validation.