Our study utilized 374 geographical distribution records of H. mutabilis and 19 bioclimatic factors, employing the MaxEnt model and the Geographic Information System (ArcGIS). The key environmental variables influencing the suitable distribution areas of H. mutabilis were analyzed through the comprehensive contribution rate, permutation importance, and Pearson correlation coefficient. Based on this analysis, the contemporary and future suitable distribution areas and their extents were predicted. The results indicate that the key limiting factor affecting the suitable distribution areas of H. mutabilis is the precipitation of the driest month (bio14), with secondary factors being annual precipitation (bio12), annual mean temperature (bio1), and annual temperature range (bio7). Under contemporary climate conditions, the total suitable area for H. mutabilis is approximately 2,076,600 km², primarily concentrated in the tropical and subtropical regions of southeastern China. Under low-to-medium-emission scenarios (SSP1-2.6, SSP2-4.5), the total suitable area of H. mutabilis shows a trend of first decreasing and then increasing compared to the current scenario. In contrast, under high-emission scenarios (SSP5-8.5), it exhibits a trend of first increasing and then decreasing. The spatial pattern changes indicate that the retention rate of suitable areas for H. mutabilis ranges from 95.28% to 99.28%, with the distribution centers primarily located in Hunan and Guizhou provinces, showing an overall migration trend towards the west and north. These findings suggest that H. mutabilis possesses a certain level of adaptability to climate change. However, it is crucial to consider regional drought and sudden drought events in practical cultivation and introduction processes. The results of our study provide a scientific basis for the rational cultivation management, conservation, and utilization of germplasm resources of H. mutabilis.

Drought stress is a major constraint on seed germination and crop productivity, particularly for drought-sensitive crops like common buckwheat (Fagopyrum esculentum). Exogenous melatonin has emerged as a promising strategy to mitigate drought stress by enhancing plant physiological and biochemical responses. However, its specific roles in regulating antioxidant defenses, osmotic adjustment, and plant compounds biosynthesis during buckwheat seed germination under drought stress remain poorly understood. This study investigated the effects of 200 µM exogenous melatonin on common buckwheat germination under polyethylene glycol (PEG-6000)-induced drought stress. Melatonin significantly improved germination rates and radicle growth, reduced membrane damage, and enhanced osmotic regulation by increasing proline, soluble sugars, and proteins. Antioxidant enzyme activities (catalase, peroxidase, and superoxide dismutase) and associated gene expression (FtCAT, FtPOD, FtSOD) were markedly upregulated. Molecular docking and dynamics simulations revealed a stable interaction between rutin, a secondary metabolite, and catalase, suggesting enhanced enzyme stabilization. Additionally, melatonin increased rutin and methyl jasmonate synthesis, which contributed to antioxidant defenses and reduced oxidative damage. The coordinated effects of melatonin improved drought tolerance in buckwheat seeds by optimizing osmotic balance, strengthening antioxidant capacity, and stabilizing cellular structures. Exogenous melatonin enhances drought tolerance in common buckwheat seeds through the coordinated regulation of antioxidant defenses, osmotic adjustment, and plant compounds production, including methyl jasmonate and rutin, during germination. These findings offer valuable insights for developing practical strategies to improve drought resilience and crop establishment in sensitive agricultural species under water-limited conditions.

As a result of the continuous global warming in recent years, the average annual number of rain days in China has been on the decline, while the number of rainstorm days has gradually increased. These conditions make it extremely easy to form a waterlogging environment, which has an adverse impact on plant growth and development. In many apple-producing areas in China, apples are subject to severe flooding during planting. In this study, two-year-old apple rootstock M9T337 was used to explore the effects of interval water stress on the morphological and physiological parameters of apple leaves. The purpose was to determine the plant’s adaptability to waterlogged environments and provide theoretical reference for management and maintenance after waterlogging. The results showed that the effect on flooded (T2) on apple stock was greater than that of waterlogged (T1), Short-term (7 d) waterlogging (T1) did not affect the growth of seedlings but was conducive to the accumulation of dry matter. Furthermore, the initial stress was be imprinted on the plants, which could directly affect their response to later stress. The results of principal component analysis (PCA) revealed that PC1, PC2, and PC3 explained 26.92%, 17.46%, and 13.03% of the physiological changes under water stress, respectively. By calculating the weight of each indicator, we concluded that high-frequency resistance r, relative chlorophyll content (SPAD) and maximum photochemical efficiency Fv/Fm are important parameters for apple rootstocks affected by water stress.

As a result of climate change, temperate regions are facing the simultaneous increase in water and heat stress. These changes may affect the interactions between plants and pollinators, which will have an impact on entomophilous crop yields. Here, we investigated the consequences of high temperatures and water stress on plant growth, floral biology, flower-reward production, and insect visitation of five varieties of common buckwheat (Fagopyrum esculentum), an entomophilous crop of growing interest for sustainable agriculture. The plants were grown under two temperature regimes (21 °C/19 °C and 28 °C/26 °C, day/night) and two watering regimes (well-watered and water-stressed). Our results showed that the reproductive growth was more affected by drought and high temperatures than was the vegetative growth, and that combined stress had more detrimental effects. However, the impact of drought and high temperatures was variety-dependent. Drought and/or high temperatures reduced the number of open flowers per plant, as well as the floral resources (nectar and pollen), resulting in a decrease in pollinator visits, mainly under combined stress. Although the proportion of Hymenoptera visiting the flowers decreased with high temperatures, the proportion of Diptera remained stable. The insect visiting behavior was not strongly affected by drought and high temperatures. In conclusion, the modification of floral display and floral resources induced by abiotic stresses related to climate change alters plant–pollinator interactions in common buckwheat.