Nocturnal stomatal behaviour has the potential to exert a profound influence on plant-water relations, especially water use efficiency. However, we know very less about plant functional type differences in nocturnal stomatal conductance and their roles in plant stress adaptation, especially drought adaptation. To address this critical knowledge gap, we assessed diel leaf gas exchanges in eight ephemeral and perennial herbs growing on the southern edge of the Gurbantunggut Desert, Northwest China. For both ephemeral and perennial herbs, the nocturnal stomatal conductance (gs) exceeded 30 % of daytime gs, except for an ephemeral herb (Malcolmia scorpioides). The nocturnal gs in the studied perennial herbs were significantly higher than it in the ephemeral herbs. The results suggest that circadian-driven stomatal priming plays a pivotal role in accelerating the attainment of steady-state gs during the morning for perennial herbs, thereby enhancing their capacity for carbon capture. Moreover, the nocturnal stomatal behaviour of the ephemeral herbs favored water retention in the morning, consequently enhanced intrinsic water use efficiency and long-term water use efficiency. In summary, plant functional type differences in the magnitude of nocturnal stomatal opening were related to differences in water acquisition and utilization and highlighted diverse water use strategies in the desert plants.
Desert Climate , Plant Stomata , Water , China , Plant Stomata/physiology , Circadian Rhythm/physiology , Droughts
The long-term application of plant essential oils in food preservation coatings is limited by their poor water solubility and high volatility, despite their recognized synergistic antimicrobial effects in postharvest fruit preservation. To overcome these limitations, a Pickering emulsion loaded with thyme essential oil (TEO) was developed by utilizing hydrogen bonding and electrostatic interactions to induce cross-linking of chitosan particles. This novel emulsion was subsequently applied in the postharvest storage of strawberries. The shear-thinning behavior (flow index <1) and elastic gel-like characteristics of the emulsion made it highly suitable for spray application. Regarding TEO release, the headspace concentration of TEO increased from 0.21 g/L for pure TEO to 1.86 g/L after two instances of gas release due to the stabilizing effect of the chitosan particles at the oil-water interface. Notably, no phase separation was observed during the 10-day storage of the emulsion. Consequently, the emulsion was successfully employed for the postharvest storage of strawberries, effectively preventing undesirable phenomena such as weight loss, a decrease in firmness, an increase in pH, and microbial growth. In conclusion, the developed Pickering emulsion coating exhibits significant potential for fruit preservation applications, particularly for extending the shelf life of strawberries.
Chitosan , Fragaria , Oils, Volatile , Plant Oils , Thymol , Thymus Plant , Chitosan/pharmacology , Emulsions , Food Preservation , Oils, Volatile/pharmacology , Water
The status of matching degree among water, soil, and heat resources determines ecosystem stability and sustainability. Under the framework of ecosystem services related to human well-being, we constructed the matching index of water, soil, and heat resources in Central Asia by the vegetation net primary productivity (NPP) index method based on remote sensing data. We analyzed the spatio-temporal characteristics of the matching degree in Central Asia, and correlations between the matching degree and climatic factors, water use efficiency using trend analysis and the Hurst index. The results showed that the matching degree of water, soil, and heat resources was generally low in Central Asia with a mean value of 9.3. There were obvious differences in the mat-ching degree in different biomes, with the order of alpine forest region > alpine meadow region > typical steppe region > desert steppe region > lake > desert region. From 2000 to 2015, the matching degree of water, soil, and heat resources in each biome and in the whole Central Asia showed a fluctuating downward trend. However, the matching degree changed slightly, with relatively poor persistence. There was a large difference and misalignment of spatial variation in temperature and precipitation, which was the main cause of low matching degree of water, soil, and heat resources. The effect of precipitation on the matching degree of water, soil, and heat resources in Central Asia was stronger than that of the temperature. There was a strong correlation between the matching degree and water use efficiency in Central Asia.
Ecosystem , Soil , Asia , China , Hot Temperature , Humans , Water
