Aroma, an important quality characteristic of plant fruits, is produced by volatile organic compounds (VOCs), mainly terpenes, aldehydes, alcohols, esters, ketones, and other secondary metabolites, in plant cells. There are significant differences in the VOC profile of various fruits. The main pathways involved in the synthesis of VOCs are the terpenoid, phenylalanine, and fatty acid biosynthesis pathways, which involve several key enzyme-encoding genes, transcription factors (TFs), and epigenetic factors. This paper reviews the main synthetic pathways of the main volatile components in fruit, summarizes studies on the regulation of aroma formation by key genes and TFs, summarizes the factors affecting the fruit aroma formation, describes relevant studies on the improvement of fruit flavor quality, and finally proposes potential challenges and prospects for future research directions. This study provides a theoretical basis for the further precise control of fruit aroma quality and variety improvement.

Introduction: Land-use changes significantly impact soil properties in forests, which is an area of concern. Therefore, the effects of changing forest types on soil microbial communities and their functions in northern subtropical forest regions need to be further researched.Methods: We used 16S rDNA sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX) to assess the variation of soil bacterial communities and potential functions related to carbon (C) and nitrogen (N) cycling in two soil layers (0–10 and 10–30 cm) after the conversion of the secondary masson pine (Pinus massoniana, PM) forest to plantations of slash pine (Pinus elliottii, PE) and Chinese fir (Cunninghamia lanceolata, CL) located in Jingde County, Anhui Province, China.Results: The study found that converting coniferous secondary forests to coniferous plantations resulted in a notable increase in soil pH and a decrease in nitrate nitrogen and organic carbon contents. Additionally, soil microbial diversity increased significantly, and microbial community structure changed, particularly in the topsoil. These changes might affect the C- and N-cycling mediated by soil bacteria. The analysis revealed a significant decrease in the abundance of functional groups associated with C-cycling and a significant increase in the abundance of functional groups associated with N-cycling, particularly those associated with denitrification. Soil organic carbon, pH, and ammonium nitrogen were the most critical variables affecting changes in the soil microbial community.Discussion: These findings provide valuable information for ecological restoration and future sustainable forest management.

Acer palmatum is a deciduous shrub or small tree. It is a popular ornamental plant because of its beautiful leaves, which change colour in autumn. This study revealed 116 ApNAC genes within the genome of A. palmatum. These genes are unevenly distributed on the 13 chromosomes of A. palmatum. An analysis of the phylogenetic tree of Arabidopsis thaliana NAC family members revealed that ApNAC proteins could be divided into 16 subgroups. A comparison of ApNAC proteins with NAC genes from other species suggested their potential involvement in evolutionary processes. Studies suggest that tandem and segmental duplications may be key drivers of the expansion of the ApNAC gene family. Analysis of the transcriptomic data and qRT‒PCR results revealed significant upregulation of most ApNAC genes during autumn leaf senescence compared with their expression levels in summer leaves. Coexpression network analysis revealed that the expression profiles of 10 ApNAC genes were significantly correlated with those of 200 other genes, most of which are involved in plant senescence processes. In conclusion, this study contributes to elucidating the theoretical foundation of the ApNAC gene family and provides a valuable basis for future investigations into the role of NAC genes in regulating leaf senescence in woody ornamental plants.

Acer paxii belongs to the evergreen species of Acer, but it exhibits a unique feature of reddish leaves in fall in subtropical regions. Although the association of AP2/ERF transcription factors with color change has been well-documented in prior research, molecular investigations focusing on AP2/ERF remain notably lacking in Acer paxii. This research focuses on performing an extensive genome-wide investigation to identify and characterize the AP2/ERF gene family in Acer paxii. As a result, 123 ApAP2/ERFs were obtained. Phylogenetic analyses categorized the ApAP2/ERF family members into 15 subfamilies. The evolutionary traits of the ApAP2/ERFs were investigated by analyzing their chromosomal locations, conserved protein motifs, and gene duplication events. Moreover, investigating gene promoters revealed their potential involvement in developmental regulation, physiological processes, and stress adaptation mechanisms. Measurements of anthocyanin content revealed a notable increase in red leaves during autumn. Utilizing transcriptome data, transcriptomic profiling revealed that the majority of AP2/ERF genes in Acer paxii displayed significant differential expression between red and green leaves during the color-changing period. Furthermore, through qRT-PCR analysis, it was found that the gene expression levels of ApERF006, ApERF014, ApERF048, ApERF097, and ApERF107 were significantly elevated in red leaves. This indicates their potential participation in leaf pigmentation processes. These findings offer significant insights into the biological significance of ApAP2/ERF transcription factors and lay the groundwork for subsequent investigations into their regulatory mechanisms underlying leaf pigmentation in Acer paxii.