Mediator is a multiprotein complex integral to the transcription machinery, mediated by RNA polymerase II. Some Mediator subunits have been found to have critical functions in plants’ responses to abiotic stresses. However, the role of plant Mediator subunits in drought responses remains largely enigmatic. Here, we identified a Mediator subunit, RhMED15a, in roses (Rosa hybrida). Its expression was greatly and swiftly induced by dehydration treatment in the root. The promoter sequence of RhMED15a contains cis-acting elements that respond to abscisic acid (ABA) and methyl jasmonate (MeJA). In addition, the expression of RhMED15a was significantly up-regulated with ABA treatment and inversely down-regulated with MeJA treatment. Silencing RhMED15a using virus-induced gene silencing (VIGS) in roses significantly reduced drought tolerance in rose plants. This resulted in a significant increase in the malondialdehyde (MDA) level and a decreased survival rate in comparison to TRV controls. Moreover, we found that the expression of five drought-related genes, including dehydration responsive element binding factor 1B (DREB1B), responsive to desiccation stress 29A (RD29A), responsive to desiccation stress 29B (RD29B), early response to dehydration 14 (ERD14), and 9-cis-epoxycarotenoid dioxygenase 1 (NCED1), was considerably suppressed in RhMED15a-silenced plants during drought stress. Taken together, our results present that the Mediator tail module subunit RhMED15a serves as an enhancer of drought tolerance in rose, probably through the modulation of the expression of some drought-related genes.

Urban green spaces (UGSs) play an important role in improving urban ecological envi-ronments and social well-being. In this study, we selected Chengdu, China as the research area. By integrating urban big data with spatial autocorrelation analysis, we identified UGS distributions across different years and their spatial clustering patterns. Furthermore, eleven factors influencing UGS distribution were systematically selected from both city-scale and neighborhood-scale perspectives. The main factors influencing the kernel density of UGS in Chengdu were explored using geographical detectors, and the results showed that the quantity and area of UGS in Chengdu gradually increased from 2012–2021 through an unbalanced spatial distribution. All influencing factors had an interac-tive relationship with the UGS kernel density. As the UGS kernel density increased, transportation hub had the greatest impact, the influence of air pollution and urban pre-cipitation on the density of UGS increased, and the nighttime light index decreased. By categorizing the influencing factors into natural environmental and human activity di-mensions, the analysis revealed that human activities and natural environment served as primary drivers of UGS density before and after 2018, respectively. Furthermore, their ef-fects on UGS gradually expanded from the urban core to encompass the entire metropoli-tan area over time. By exploring the relationship between the evolution of UGS spatial patterns and changes in the urban ecological environment and social development using a quantifiable method, this study provides references and guidelines for the future plan-ning of cities to achieve high-quality development.