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Ethylene, a plant hormone that significantly influences both plant growth and response to stress, plays a well-established role in stress signaling. However, its impact on stomatal opening and closure during dehydration and rehydration remains relatively unexplored and is still debated. Exogenous ethylene has been proven to induce stomatal closure through a series of signaling pathways, including the accumulation of reactive oxygen species, subsequent synthesis of nitric oxide and hydrogen sulfide, and SLOW ANION CHANNEL-ASSOCIATED 1 activation. Thus, it has been suggested that ethylene might function to induce stomatal closure synergistically with abscisic acid (ABA). Furthermore, it has also been shown that increased ethylene can inhibit ABA- and jasmonic acid-induced stomatal closure, thus hindering drought-induced closure during dehydration. Simultaneously, other stresses, such as chilling, ozone pollution, and K+ deficiency, inhibit drought- and ABA-induced stomatal closure in an ethylene synthesis-dependent manner. However, ethylene has been shown to take on an opposing role during rehydration, preventing stomatal opening in the absence of ABA through its own signaling pathway. These findings offer novel insights into the function of ethylene in stomatal regulation during dehydration and rehydration, giving a better understanding of the mechanisms underlying ethylene-induced stomatal movement in seed plants. [ABSTRACT FROM AUTHOR]

Leaf hydraulic traits are considered the key determinants of gas exchange and therefore affect species distributions along environmental gradients, but the patterns of leaf hydraulic traits and their associations with gas exchange across altitudinal gradients remain largely unknown.Here, we measured leaf hydraulic traits, gas exchange, leaf anatomical traits and plant size traits in two dominant alpine shrubs (Caragana jubata and Salix gilashanica) across an altitudinal gradient from 3100 to 3700 m.The findings indicated that with increasing altitude, both shrub species exhibited an increase in leaf hydraulic safety (more negative KleafP50), a decrease in leaf hydraulic efficiency (Kleaf‐max) and an increase in intrinsic water use efficiency (WUEi), thus allowing them to adapt to higher altitude habitats. The more negative KleafP50 was associated with a greater ratio of major to minor vein density (VLAmaj/VLAmin), the lower Kleaf‐max was associated with a lower minor vein density (VLAmin) and greater increase in WUEi arose from the small decrease in the photosynthetic rate relative to the stomatal conductance. However, C. jubata was consistent with the 'hydraulic safety strategy' with a great decrease in KleafP50, a small decrease in Kleaf‐max and a small increase in WUEi along with decreasing plant height and leaf area with increasing altitude. Whereas S. gilashanica was consistent with the 'photosynthetic efficiency strategy' with a small decrease in KleafP50, a greater decrease in Kleaf‐max and a greater increase in WUEi along with an increasing plant height and unchanged leaf area with increasing altitude.Overall, these findings provide new insights to improve understanding how shift in leaf hydraulic traits and their associations with gas exchange and plant size allow plants to adapt to high‐altitude habitats. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Plastic pollution, particularly uncollected polythene fragments, has been identified as a significant driver of environmental change. This study investigated the effects of plastic fragments on soil multifunctionality (SMF) and bacterial communities in dryland ecosystems. The results showed that small and medium-sized fragments negatively impacted SMF, while large fragments had minimal effects. The study also found that the bacterial community characteristics and co-occurrence patterns played a crucial role in mediating the effects of plastic fragments on SMF. Overall, this research provides valuable insights into the long-term impacts of plastic pollution on soil ecosystems. [Extracted from the article]

ABSTRACT Determining the differences in flower hydraulic traits and structural resource allocation among closely related species adapted to low mean annual precipitation (MAP) can provide insight into plant adaptation to arid environments. Here, we measured the maximum flower hydraulic conductance (Kmax‐flower), water potential at induction 50% loss of Kmax‐flower (P50‐flower), flower pressure–volume parameters, dry mass of individual flowers and structural components (vexillum, wings, keels, stamens and sepals) of six Caragana species growing in regions ranging from 110 to 1400 mm MAP. Compared with species from high‐MAP environments, those from low‐MAP environments presented lower Kmax‐flower, more negative P50‐flower, osmotic potential at full turgor (πo) and turgor loss points (πtlp), and a greater bulk modulus of elasticity (ε). Consequently, a negative correlation between Kmax‐flower (hydraulic efficiency) and P50‐flower (hydraulic safety) was observed across Caragana species. Furthermore, the dry masses of individual flowers and structural components (vexillum, wings, keels, stamens and sepals) were greater in the species from the low‐MAP environment than in those from the high‐MAP environment. These findings suggest that greater flower hydraulic safety and drought tolerance combined with greater structural resource allocation promote drought adaptation in Caragana species to low‐MAP environments. [ABSTRACT FROM AUTHOR]