Climate change and environmental pollution have increased the frequency and severity of extreme weather events, exposing plants to multifactorial stress conditions that are poorly understood. While extensive research has explored plant responses to individual stress factors, the impact of combined stresses-such as microplastic (MP) contamination and freeze-thaw cycles-remains largely unexamined. This research investigated how soil microplastic pollution affects the freezing tolerance of cabbage (Brassica oleracea L.), a crop vulnerable to unexpected frosts. Seedlings were grown in soils containing varying MP concentrations (0 %, 2 %, 5 %, and 10 % w/w), and their physiological responses to freezing events (-2.5 degrees C and -3.5 degrees C) were assessed. Our findings revealed that although MP particles were not detected in leaf tissues, MP contamination significantly reduced freezing tolerance in a dose-dependent manner. Plants grown in 10 % MP-treated soil exhibited higher membrane damage, as indicated by increased ion leakage and malondialdehyde levels, and showed more severe oxidative stress, with elevated superoxide (O-2(center dot-)) and hydrogen peroxide (H2O2) accumulation. These stress responses corresponded with suppressed antioxidant enzyme activities, including catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). Principal component analysis (PCA) demonstrated distinct physiological patterns between control and MP-treated plants, emphasizing the disruptive impact of MP pollution on stress resilience. This study provides the first empirical evidence that soil microplastic contamination compromises plant tolerance to freeze-thaw cycles, highlighting an overlooked risk to crop performance in changing environmental conditions and calling for further research into the long-term ecological consequences of terrestrial MP pollution.

A discrete warming event (December 21, 2001-January 12, 2002) in the McMurdo Dry Valleys, Antarctica, enhanced glacier melt, stream flow, and melting of permafrost. Effects of this warming included a rapid rise in lake levels and widespread increases in soil water availability resulting from melting of subsurface ice. These increases in liquid water offset hydrologic responses to a cooling trend experienced over the previous decade and altered ecosystem properties in both aquatic and terrestrial ecosystems. Here, we present hydrological and meteorological data from the McMurdo Dry Valleys Long Term Ecological Research project to examine the influence of a discrete climate event (warming of > 2 degrees C) on terrestrial environments and soil biotic communities. Increases in soil moisture following this event stimulated populations of a subordinate soil invertebrate species (Eudorylaimus antarcticus, Nematoda). The pulse of melt-water had significant influences on Taylor Valley ecosystems that persisted for several years, and illustrates that the importance of discrete climate events, long recognized in hot deserts, are also significant drivers of soil and aquatic ecosystems in polar deserts. Thus, predictions of Antarctic ecosystem responses to climate change which focus on linear temperature trends may miss the potentially significant influence of infrequent climate events on hydrology and linked ecological processes.