Fujian Agriculture and Forestry University

Xu K., Yin L., Chen Q., Liao D., Ji X., Zhang K., Wu Y., Xu L., Li M., Fan X., Zhang F., Huang Z., Chen J., Hong Y.

Aerosol acidity (pH) plays an important role in the multiphase chemical processes of atmospheric particles. In this study, we demonstrated the seasonal trends of aerosol pH calculated with the ISORROPIA-II model in a coastal city of southeast China. We performed quantitative analysis on the various influencing factors on aerosol pH, and explored the responses of aerosol pH to different PM2.5 and O3 pollution levels. The results showed that the average aerosol pH was 2.92 ± 0.61, following the order of winter > spring > summer > autumn. Sensitivity tests revealed that SO42−, NHx, T and RH triggered the variations of aerosol pH. Quantitative analysis results showed that T (37.9%-51.2%) was the main factors affecting pH variations in four seasons, followed by SO42− (6.1%-23.7%), NHx (7.2%-22.2%) and RH (0–14.2%). Totally, annual mean meteorological factors (52.9%) and chemical compositions (41.3%) commonly contributed the aerosol ΔpH in the coastal city. The concentrations of PM2.5 was positively correlated with aerosol liquid water content (R2 = 0.53) and aerosol pH (R2 = 0.26), indicating that the increase in pH was related with the elevated NH4NO3 and decreased SO42−, and also the changes of T and RH. The Ox (O3 + NO2) was moderately correlated with aerosol pH (R2 = -0.48), attributable to the fact that the proportion of SO42− increased under high T and low RH conditions. The study strengthened our understanding of the contributions of influencing factors to aerosol pH, and also provided scientific evidences for chemical processes of atmospheric particles in coastal areas.

Wu T., Zhan F., Zeng L., Sun Y., Fu S., Fang Y., Lin X., Lin H., Su J., Cai S.

ABSTRACT Beauveria bassiana ( Bb ) is one of the most widely used biocontrol agents, and its products constitute more than one-third of the global market share of fungal insecticides. Solid-state fermentation (SSF) is widely used in the production of Beauveria bassiana ( Bb ) because of its economic practicality and high production efficiency. However, the heat generated during fermentation can sharply reduce both the yield and quality of Bb , and current industrial methods to mitigate high temperatures during fermentation are inadequate, leading to increased production costs. Thus, exploring the underlying mechanism of how heat is produced by Bb is crucial for improving the SSF procedure and yield. This study employed multiomics data analysis of Bb during SSF to explore the relationships between fungal fermentation and environmental factors. We found that the heat production period for SSF was 12 hours to 48 hours post-inoculation. To further explore the underlying mechanism during this heating period, we identified 454 temperature-correlated metabolites (TCMs) and 1,994 temperature-correlated genes (TCGs). Annotations of the above TCMs and TCGs revealed significant enrichment in the arginine biosynthesis pathway; specifically, the expression level of glutamine synthetase, a TCG, decreased with fermentation time, whereas the expression levels of the TCGs L-arginine and L–glutamine increased with fermentation time, and glutamine synthetase and L-glutamine in the arginine biosynthesis pathway cycle produced the end product L-arginine. Furthermore, when the substrates of the SSF were treated with exogenous arginine, the temperature peak of the SSF significantly decreased with increasing concentration of exogenously added arginine. IMPORTANCE A large amount of experimental evidence from the field has shown that Bb is an irreplaceable mature product that protects the health of our agriculture and ecosystem. In addition to high efficiency and host extensiveness, low cost is a critical merit that makes Bb products frequently used in the field. However, the growing cost of power and labor in the Bb industry, especially the SSF procedure, has significantly increased the price of its products, thus restricting the use of Bb in the field. This study not only fills the theoretical knowledge gaps concerning the molecular basis of the interrelationship between Bb and the fermentation environment during SSF but also provides an economical and applicable strategy (the addition of arginine to the fermentation media) to further lower the cost and increase the yield of Bb during SSF at the industrial level.

Chen M., Xu S., Ye Y., Lin K., Lan W., Cao G.

Chinese fir (Cunninghamia lanceolata) is an important fast-growing tree species for timber production and ecological protection in China. Yet, its tissue culture for seedling propagation is hampered by low proliferation and poor quality. Light quality is vital for seedling proliferation and growth, but the regulatory mechanisms remain poorly understood. In this study, a transcriptome and metabolome were integrated to explore light quality’s effects on adventitious shoot proliferation of tissue-cultured Chinese fir seedlings. The seedlings were grown under red, green, blue, and composite light-emitting diode conditions, with white light as the control. Results showed that blue and blue-dominant composite light enhanced proliferation by promoting auxin and cytokinin and increased biomass. Red light promoted shoot height, leaf area, and carotenoid content due to elevated gibberellin and reduced auxins and cytokinin levels but inhibited proliferation due to hormonal imbalances. Green light increased abscisic acid levels and suppressed growth. Transcriptome and metabolome analyses identified key pathways including plant hormone signal transduction, photosynthesis, and flavonoid and carotenoid biosynthesis. Weighted gene co-expression network analysis (WGCNA) identified four key genes regulated by light quality that further modulated hormone biosynthesis and signaling transduction. This research provided insights for optimizing Chinese fir seedling proliferation and growth, contributing to sustainable plantation management.

Ye Y., Abulizi A., Zhang Y., Lu F., An Y., Ren C., Zhang H., Wang Y., Lin D., Lu D., Li M., Yang B.

Ulcerative colitis (UC) is a chronic and recurrent gastrointestinal disease that affects millions of humans worldwide and imposes a huge social and economic burden. It is necessary to find safe and efficient drugs for preventing and treating UC. The aim of this study was to determine whether ganoderic acid (GA), the main bioactive components of Ganoderma lucidum, has preventive and therapeutic effect on UC in a dextran sulfate sodium (DSS)-induced UC mouse model. Our experimental results showed that GA significantly ameliorated the body weight loss and disease activity index (DAI) of UC mice. GA significantly restored 11% of the colon length and 69% of the spleen index compared to UC mice. GA significantly decreased the intestinal inflammatory response and improved the barrier function of the intestine by upregulating the tight junction proteins Zonula occludens-1 (ZO-1), occludin and claudin-1. A co-housing experiment showed that gut microbiota accounted for the therapeutic activity of GA on UC, which was confirmed by fecal microbiota transplantation from GA-treated mice to the UC mice. Furthermore, 16S rDNA high-throughput sequencing of fecal bacteria showed that GA significantly enriched the abundance of Lactobacillus, Oscillospira, Odoribacter and Ruminococcus, which were positively correlated with colon length. Furthermore, this study found the functional metabolites, including Indole-3-acetaldehyde (IAAld), Glutamine (Gln) and Glutathione (GSH), reduced barrier damage in the Caco-2 cell model. In conclusion, this study suggests that GA could ameliorate UC by improving intestinal barrier function via modulating gut microbiota and associated metabolites.

Liao K., Wang Z., Zhang Y.

Pan X., Li X., Wang R., Wang Z., Ni Y., Wang Q.

Lian Y., Peng L., Shi X., Zheng Q., Fan D., Feng Z., Liu X., Ma H., Cao S., Chang W.

GOLDEN2-LIKE (GLK) transcription factors are crucial regulators of chloroplast development and stress responses in plants. In this study, we investigated the GLK gene family in Phoebe bournei (Hemsl.) Yen C. Yang, a near-threatened species important for forestry and wood utilization in China. We identified 61 PbGLK genes which were classified into seven subfamilies. Our analyses of their phylogenetic relationships, gene structures, and chromosomal distribution revealed diverse characteristics. Expression profiling under different tissues and abiotic stresses showed that PbGLK25 and PbGLK30 were particularly responsive to drought, heat, light, and shade stresses, with significant upregulation. These findings highlight the potential role of PbGLK genes in stress adaptation and provide insights for the genetic improvement of P. bournei.

Zhang Y., Wang M., Xu W., Zang H., Yan T., Wu T., Huang K., Chen D., Luo Q., Guo R., Qiu J.

Piwi-interacting RNAs (piRNAs) play an essential part in transposon suppression, DNA methylation, and antiviral responses. The current understanding of the roles of piRNAs in honeybees is very limited. This study aims to analyze the expression pattern and regulatory role of piRNAs in the Asian honeybee (Apis cerana) responding to infection by Nosema ceranae, based on previously gained small RNA-seq data. Here, 450 and 422 piRNAs were respectively identified in the midgut tissues of Apis cerana cerana workers at 7 and 10 days post-inoculation (dpi) with N. ceranae, including 539 non-redundant ones. Additionally, one up-regulated (piR-ace-1216942) and one down-regulated (piR-ace-776728) piRNA were detected in the workers’ midgut at 7 dpi, targeting 381 mRNAs involved in 31 GO terms, such as metabolic processes, catalytic activity, and organelles, as well as 178 KEGG pathways, including lysosome, MAPK signaling pathway, and purine metabolism. A total of 35 up-regulated and 11 down-regulated piRNAs were screened from the workers’ midgut at 10 dpi, targeting 13,511 mRNAs engaged in 50 GO terms, such as biological regulation, transporter activity, and membrane, as well as 389 KEGG pathways, including the JAK-STAT signaling pathway, Hippo signaling pathway, and nitrogen metabolism. Further analysis indicated that 28 differentially expressed piRNAs (DEpiRNAs) in the midgut at 10 dpi could target 299 mRNAs annotated to three cellular immune pathways (lysosome, endocytosis, and phagosome), while 24 DEpiRNAs could target 205 mRNAs relevant to four humoral immune pathways (FoxO, JAK-STAT, NF-κB, and MAPK signaling pathway). Through Sanger sequencing and RT-qPCR, the expression of six randomly selected DEpiRNAs was verified. Moreover, the dual-luciferase reporter gene assay confirmed the binding relationships between piR-ace-446232 and CRT as well as between piR-ace-1008436 and EGFR. Our findings not only contribute to enrich our understanding of the role of piRNAs in honeybees but also provide a basis for exploring the host response to N. ceranae infection mediated by piRNAs.

Zhang Y., Chen J., Li C., Zhang L., Sun S.

Jin Y., Chen X., Li M., Zhang X., Cai W., Shen J., Zhang Y., Gao F.

Maize, a staple food and cash crop worldwide, also serves as a critical industrial raw material. However, it is significantly threatened by viral pathogens, particularly maize dwarf mosaic virus (MDMV), the primary cause of maize dwarf mosaic disease, a debilitating condition affecting maize cultivation. This study aims to establish a multi-gene combined RT-PCR assay for the rapid specific, sensitive, and reliable detection of MDMV without the need for special expensive equipment. Samples of imported maize, sorghum, and barley were collected from ports in Fujian and Shanghai. Primers targeting the coat protein (CP) and cytoplasmic inclusion protein (CI) genes of MDMV were designed and optimized. Through the design and screening of primers, as well as the optimization of reaction conditions and primer concentrations, a multi-gene combined RT-PCR assay was established to simultaneously detect both genes. Additionally, a real-time fluorescent-based RT-PCR (RT-qPCR) assay was developed using the CP gene to confirm the accuracy of multi-gene combined RT-PCR assay. The sensitivity of the optimized multi-gene combined RT-PCR assay enables the detection of MDMV in infected maize leaf crude extracts at dilutions of 5.37 pg/μL. This assay exhibited excellent specificity, high sensitivity, and robust repeatability, providing swift and accurate detection of MDMV. The multi-gene combined RT-PCR assay offers precise and efficient technical support for MDMV detection and contributes to improved maize production practices.

Liu R., Feng Y., Li Q., Wu H., Guo S., Li J., Liu X., Zhang Y., Tang X., Cao S.

The CPP gene family comprises transcription factor genes containing a conserved CRC domain, which is mainly involved in plant development and evolution. Although CPP genes have been widely studied in many plants, little is known about them in woody plants, especially in the endangered species Phoebe bournei (Hemsl.). In the genome of Phoebe bournei, we identified 11 PbCPP genes (PbCPP1-PbCPP11) distributed on four chromosomes, with large differences in the number of amino acids. They encode both acidic and alkaline proteins. A phylogenetic analysis showed that these PbCPP genes can be divided into three subfamilies, A, B, and C, which contain seven, two, and two genes, respectively. Through an interspecific collinearity analysis, we identified homologous PbCPP genes. A promoter cis-acting element analysis revealed that PbCPPs contain a variety of elements that respond to plant hormones, stress signals, and light and play a role in growth and development, and most PbCPP genes (except PbCPP3 and PbCPP8) contain MYB binding site elements that regulate drought-induced stress responses, indicating that they play an important role in plant drought resistance. An expression analysis showed that PbCPP3 and PbCPP4 expression was high in the roots and stems and lower in the leaves, whereas the expression of most of the other genes was low in the roots, stems, and leaves. In addition, six representative PbCPP genes were detected using qRT-PCR. The results show significant differences in the expression of PbCPP genes under abiotic stress conditions (drought, cold, and salt), indicating that they play an important role in stress responses. This study preliminarily verified the role of the PbCPP gene family in different abiotic stress responses, which is of great significance for understanding its mechanism in plant growth and development and stress adaptation.

Chen J., Wei L., Xie J., Zhang Y., Jia J., Chen L., Sun S.

Tremella fuciformis Berk., also known as white fungus and snow fungus, is one of the important edible and medicinal mushrooms in China. The quality characteristics and metabolites of different T. fuciformis varieties directly affect the stability of their processed products. In this study, two new varieties of Tremella fuciformis, namely ’TYH-SD1’ (yellow) and ’TWH-SD2’ (white), which were obtained by the team through single-spore crossbreeding and its control varieties Tr21 (yellow) and Tr01 (white), were used as test materials. The characteristics and nutritional quality of the four varieties of substrates were comparatively analyzed, while metabolomics was employed to investigate the differences in flavor substances. The results demonstrate that TYH-SD1 and TWH-SD2 had a higher rehydration rate and faster rehydration speed compared with the control strains Tr21 and Tr01, with a smaller stem and higher yield. Notably, TWH-SD2 had a 29.06% increase in its rehydration rate and it had higher contents of crude polysaccharide and vitamin D3. The surface of TYH-SD1 ear pieces exhibited a porous structure with a larger pore size and the surface of TWH-SD2 ear pieces displayed a surface characterized by connected gully-like protrusions and fewer indentations, which were significantly different from that of Tr21 and Tr01 ear pieces. The textural analysis shows that TYH-SD1 and TWH-SD2 ear pieces were softer and more elastic, with greater cohesion and recovery, indicating that they had high tensile and deformation recovery ability. Metabolomics analysis revealed that the relative content of aldehydes in the volatile flavor substances TYH-SD1 and TWH-SD2 was high in n-alpha-aldehyde, nonanaldehyde, and n-pentanal. The relative content of alkanes in TYH-SD1 was second only to that of aldehydes, with decane having the highest content, contributing to its more almond aroma, fruity aroma, and fat aroma. TWH-SD2 exhibited the highest concentration of alcohols, accounting for 43.57%, which may result in a clear, mushroom, and lipid odor. The above results will provide theoretical basis for the further production, processing, and application of the new varieties.

Qiu W., Jia D., Guo R., Zhang L., Wang Z., Hu X.

The expansion of road networks profoundly affects ecological systems by intensifying habitat fragmentation, altering hydrological processes, and exacerbating pollution. However, our understanding of the multi-scale spatiotemporal coupling between road networks and ecological quality remains limited. Thus, taking Fuzhou City in Southeastern China as a case study (~12,000 km2), we apply bivariate spatial autocorrelation, geographical detectors (GDs), and multi-scale geographically weighted regression (MGWR) to explore the multi-scale interactions between road networks and ecological quality. Results reveal the following: (1) From 2016 to 2021, kernel density estimation (KDE) analysis of the road network indicates coordinated growth in both urban and rural areas, with an increase of 0.759 km/km2. Analysis based on the remote sensing-based ecological index (RSEI) shows a decrease from 2000 to 2016, and then an increase from 2016 to 2021, with a trend of increasing gradually from urban center to rural area. (2) Predominant tradeoff relationships exist between KDE and RSEI in 2016 and 2021, while notable synergistic relationships emerge between ΔKDE and ΔRSEI. (3) Multi-scale GD analysis identifies ΔKDE as a principal factor influencing ΔRSEI, and the MGWR reveals their significant synergistic associations at an optimal scale of 3000 m. These findings highlight the unequal impact of road network expansion on ecological quality, underscoring the pivotal role of road density changes in its spatiotemporal dynamics. They offer essential insights for sustainable transport and ecological planning.

Cheng K., Chen X., Yi Y., Wang Y., Tian M., Yu J., Xia Y., Li J., Zhang M., Ding C.

You N.