Phyllanthus emblica L., a medicinal and edible fruit, is valued for its exceptionally high ascorbic acid (AsA) content, but postharvest senescence and rapid pericarp browning severely limit its marketability. In this study, ellagic acid (EA) was applied to harvested emblica fruit to elucidate its effects on postharvest quality deterioration and pericarp browning, as well as the underlying physiological and molecular mechanisms. EA treatment delayed the loss of fruit marketability and the increase in browning index, while reducing cell membrane permeability, lipid peroxidation and reactive oxygen species (ROS) accumulation. Moreover, EA treatment enhanced SOD and CAT activities and restrained the increases in PPO and POD activities. Additionally, higher AsA and GSH contents and AsA/DHA and GSH/GSSG ratios were maintained in EA-treated fruit, together with higher activities and transcript abundance of enzymes involved in the AsA-GSH cycle. Notably, a novel PemiR477-PeAPX2 module was identified, and the targeting relationship between PemiR477 and PeAPX2 was validated in vivo. EA treatment suppressed PemiR477 expression while maintaining higher transcript levels of PeAPX2 during storage, in parallel with enhanced APX activity and a more reduced AsA pool. Collectively, these results suggested that EA treatment effectively delayed postharvest senescence and pericarp browning of emblica fruit by regulating PemiR477-PeAPX2 module and maintaining AsA-GSH redox homeostasis.
Large-scale urban afforestation is increasingly promoted as a Nature-Based Solution for reducing urban heat. Yet afforestation does not cool cities uniformly, and the conditions under which it delivers sustained thermal benefits remain poorly understood. This uncertainty limits the ability of planners to design and manage effective afforestation strategies. Using the Beijing Plain Area Afforestation Programme (BPAP) as a large-scale natural experiment, we combined satellite observations, a paired-site framework, and surface-energy-balance analysis to investigate how thermal responses to afforestation evolved between 2015 and 2023. Most afforested sites experienced progressive cooling, but approximately 37% followed warming trajectories. Cooling developed gradually through a maturation process and was consistently associated with increasing latent heat flux, whereas warming sites exhibited limited improvement in evapotranspirative functioning over time. These contrasting trajectories indicate that thermal performance depends not simply on tree establishment, but on the capacity of afforested ecosystems to develop and sustain key biophysical functions. Our findings indicate that cooling from large-scale urban afforestation is conditional rather than universal. They provide a transferable framework for landscape planning by shifting attention from tree-cover targets toward ecosystem performance, long-term monitoring, and site-specific management under increasing climatic and hydrological constraints.
The WUSCHEL (WUS) transcription factor is the central organizer of shoot apical meristem (SAM) stem cells, yet its functions in woody plants remain poorly understood. This review synthesizes current knowledge of WUS and WUS-related homeobox (WOX) family genes in forest trees, spanning evolutionary genomics, vascular cambium regulation, somatic embryogenesis(SE), hormonal and environmental signal integration, and biotechnological applications. Comparative genomic analyses reveal “transitional” WUS genes in gymnosperms, illuminating the evolutionary trajectory from ancient to modern meristem regulation. In the vascular cambium unique to woody plants, WOX4 maintains cambial cell identity and prevents ectopic xylem differentiation, while contrasting CLAVATA3/EMBRYO SURROUNDING REGION-related(CLE) peptide pathways—the CLAVATA3(CLV3)-WUS negative feedback in the SAM versus the TDIF-PXY-WOX4 positive axis in the cambium—highlight WUS/WOX functional diversification across meristems. We discuss how WUS and derived functional peptides overcome regeneration recalcitrance, a major bottleneck in forest tree genetic transformation, and examine how cytokinin(CK)–auxin cross-talk, light, nutrient, and abiotic stress signals modulate WUS/WOX expression. Finally, we outline strategies for deploying CRISPR-based WUS regulation to improve wood properties, plant architecture, and stress resilience in forest trees. This integrative perspective positions the WUS/WOX family as a central nexus linking stem cell biology, environmental adaptation, and applied tree breeding. This review elucidates the evolutionary role of WUSCHEL in vascular cambium homeostasisand highlights the deployment of WUS-derived functional peptides to overcome regenerationrecalcitrance in woody perennials.
Soil heterotrophic respiration (Rh) is critical for ecosystem carbon balance, but how microbial genomic adaptation to extreme drought across plant growth stages regulates Rh remains poorly understood. This study aimed to determine how drought-enriched bacteria adjust genome size, functional traits, and carbon acquisition capacity, and how these changes affect Rh in an alpine peatland. We conducted a field extreme-drought manipulation experiment in an alpine peatland during the early, middle, and late plant growth stages. Metagenomic sequencing was used to identify drought-enriched bacteria and characterize their genome size, KEGG functional potential, drought-resistance genes, and carbon-acquisition-related genes. Soil hydrolytic enzyme activities and Rh were measured, and structural equation modeling was used to assess direct and indirect pathways regulating Rh. Drought-enriched bacteria consistently had smaller genomes than drought-depleted bacteria, supporting genome streamlining under drought stress. However, among drought-enriched groups, genome size and functional potential peaked in the middle stage, with genome size reaching 4.83 Mb compared with 4.04 Mb in the early stage and 3.66 Mb in the late stage. Under extreme drought, carbon-acquisition-related genes were most enriched in the middle stage, increasing by 15.8
Soil microorganisms are central to soil nutrient cycle by mediating organic matter decomposition and nutrient transformation. However, how changes in their physical and chemical environment across developmental stages of forest plantations accompanied by influence of the metabolic activity and nutrient use efficiency of rhizosphere microbes, and consequently, soil nutrient dynamics, remains poorly understood. We investigated rhizosphere soil microbial carbon and nitrogen use efficiencies (CUE and NUE) in subtropical Pinus massoniana plantations across 5, 9, 19, 29 and 35 years, for both growing and non-growing seasons. Soil microbial CUE and NUE were consistently higher in the non-growing season than in the growing season, likely due to higher nitrogen and lower carbon (C) content in litter and total potassium (K) concentration, which altered microbial substrate availability. Across stand development, CUE and NUE followed a pattern of initial increase, subsequent decline and later recovery. During the growing season, changes in CUE were mainly positively influenced by litter N content, whereas in the non-growing season, CUE was positively associated with rhizosphere soil total K concentration. These shifts in soil CUE and NUE across stand development stages were further linked to changes in enzyme activities, with beta-glucosidase and peroxidase negatively associated with CUE and leucine aminopeptidase positively associated with NUE. Across stand ages, both CUE and NUE followed a non-linear trajectory, suggesting complex interactions between litter inputs and rhizosphere available nutrient over time. Synthesis and applications. Microbial nutrient processing is strongly shaped by seasonal stoichiometric conditions and enzyme-mediated substrate decomposition. This highlights the importance of considering seasonal and developmental stage-specific management to optimize microbial function for improved forest productivity and carbon storage.
