Ochratoxin A (OTA) is a potent nephrotoxic, hepatotoxic, and teratogenic compound which is a significant mycotoxin contaminates cereals during storage. Aspergillus ochraceus is the most common producer of OTA in cereals and cereal-derived products. Cinnamaldehyde is a natural substance derived from plant cinnamon playing an important role in the reduction of OTA contamination. In this study, the antifungal and antitoxigenic effect of cinnamaldehyde was investigated with its mechanisms of inhibition of fungal growth at the morphological and ultrastructural levels, and inhibition of OTA biosynthesis at the transcriptional level. Significant A. ochraceus growth was inhibited at 0.4⁻1.6 mmol/L with fumigation. A. ochraceus exposed to 0.4 mmol/L of cinnamaldehyde indicated irreversible harmful morphological and ultrastructural modifications such as the folding of the cell, the loss of integrity of the cell wall, the disruption of plasma membrane, the destruction of the mitochondria, and the absence of intracellular organelles. These alterations may be attributed to its inhibition of enzymatic reactions that regulate cell wall synthesis, thus disturbing the morphogenesis and growth of A. ochraceus. In the presence of cinnamaldehyde, the tested biosynthetic and regulatory genes like pks, nrps, veA, laeA and velB were highly downregulated. Moreover, the downregulation effect of cinnamaldehyde increased proportionally with the concentrations. These results suggest that the decrease of OTA production by cinnamaldehyde is attributed to the downregulation of the transcriptional levels of OTA biosynthetic and regulatory genes besides the inhibition of fungal growth. The study reveals the mechanisms of the antifungal and antitoxigenic activities of cinnamaldehyde against A. ochraceus, and further emphasizes that cinnamaldehyde could be a safe and effective natural agents against OTA contamination during cereals storage.
The contamination of peanuts with Aspergillus sp. and subsequently aflatoxins is considered to be one of the most serious safety problems in the world. Mycobiome in peanuts is critical for aflatoxin production and food safety. To evaluate the biodiversity and ecological characteristics of whole communities in stored peanuts, the barcoded Illumina paired-end sequencing of the internal transcribed spacer 2 (ITS2) region of rDNA was used to characterize the peanut mycobiome monthly over a period of 1 year at four main peanut grown areas, i.e., Liaoning (LN, North East), Shandong (SD, East), Hubei (HB, Central), and Guangdong (GD, South) provinces. The fungal diversity of peanuts stored in SD was the highest with 98 OTUs and 43 genera, followed by LN, HB and GD. In peanuts stored in SD, Rhizopus, Emericella, and Clonostachys were predominant. In peanuts from LN, Penicillium, Eurotium, and Clonostachys were abundant. In peanuts from HB, Penicillium, Eurotium, and Aspergillus were higher. In GD peanuts, Eurotium, Aspergillus, and Emericella were mainly seen. The abundances of Aspergillus in LN, SD, HB, and GD were 0.53, 6.29, 10.86, and 25.75%, respectively. From the North of China to the South, that increased over the latitude, suggesting that the higher temperature and relative humidity might increase the risk of peanuts contaminated with Aspergillus and aflatoxins. During the storage, Aspergillus levels were higher at 7-12 months than in 0-6 months, suggesting that the risk increases over storage time. At 7-10 months, AFB1 was higher in four areas, while declined further. The reduction of AFB1 might be attributed to the inhibition and degradation of AFB1 by Aspergillus niger or to the combination with the compounds of peanuts. This is the first study that identified the mycobiome and its variation in stored peanuts using ITS2 sequencing technology, and provides the basis for a detailed characterization of whole mycobiome in peanuts.
Abstract In order to reveal the inhibitory effects of cinnamaldehyde, citral, and eugenol on aflatoxin biosynthesis, the expression levels of 5 key aflatoxin biosynthetic genes were evaluated by real‐time PCR. Aspergillus flavus growth and AFB 1 production were completely inhibited by 0.80 mmol/L of cinnamaldehyde and 2.80 mmol/L of citral. However, at lower concentration, cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L) significantly reduced AFB 1 production with inhibition rate of 68.9%, 95.4%, and 41.8%, respectively, while no effect on fungal growth. Real‐time PCR showed that the expressions of aflR , aflT , aflD , aflM , and aflP were down‐regulated by cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L). In the presence of cinnamaldehyde, AflM was highly down‐regulated (average of 5963 folds), followed by aflP , aflR , aflD , and aflT with the average folds of 55, 18, 6.5, and 5.8, respectively. With 0.80 mmol/L of eugenol, aflP was highly down‐regulated (average of 2061‐folds), followed by aflM , aflR , aflD , and aflT with average of 138‐, 15‐, 5.2‐, and 4.8‐folds reduction, respectively. With 0.56 mmol/L of citral, a flT was completely inhibited, followed by aflM , aflP , aflR , and aflD with average of 257‐, 29‐, 3.5‐, and 2.5‐folds reduction, respectively. These results suggest that the reduction in AFB 1 production by cinnamaldehyde, eugenol, and citral at low concentration may be due to the down‐regulations of the transcription level of aflatoxin biosynthetic genes. Cinnamaldehyde and eugenol may be employed successfully as a good candidate in controlling of toxigenic fungi and subsequently contamination with aflatoxins in practice.
In group-living animals, chronic social isolation stress (SIS) during the juvenile can profoundly affect behavior and neuroendocrine systems. However, how SIS influences the social behavior of avian species, particularly regarding sex-specific differences at the neural circuit level, remains poorly explored. This study focuses on zebra finches — a species noted for social clustering and cognitive abilities — to reveal significant insights into these effects. We found that SIS increased plasma corticosterone levels in females but not in males, suggesting a higher susceptibility in females. SIS adversely affects sociality and flocking behavior in both sexes, but it has a more pronounced impact on social recognition in females. Mesotocin (MT) levels in the lateral septum of both sexes and the ventromedial hypothalamus of females play an important role in mediating the SIS effect, while vasotocin (VT) levels in the social behavior network remain unaffected. Pharmacological interventions underscore the critical role of MT in reversing SIS-induced impairments in sociality, flocking behavior, and social recognition, particularly in females. Our findings uncover unique nucleus- and sex-dependent variations in MT and VT levels in avian models. This study offers novel insights into sex-specific mechanisms regulating social behavior in birds and contributes to a broader understanding of the independent evolution of neural circuits and neuroendocrine systems that govern social behaviors across different taxonomic groups.
In order to optimize water and fertilizer use in the double-cropping rice in eastern Fujian Province, a field runoff plot experiment was conducted to investigate rice yield, nutrient uptake, and runoff losses of N (nitrogen) and P (phosphorus) in the T0(no chemical fertilization with traditional flooding irrigation), T1(common chemical fertilizer of 273 kg N·hm-2, 59 kg P·hm-2, and 112 kg K·hm-2 combined with traditional flooding irrigation), T2(chemical fertilizer of 240 kg N·hm-2, 52 kg P·hm-2, and 198 kg K·hm-2 combined with traditional flooding irrigation) and T3(chemical fertilizer combined with shallow intermittent irrigation) treatments. Results showed that early rice grain yield in the T1, T2 and T3 treatments significantly increased by 0.7, 1.0, 1.1 times, late rice grain yield significantly increased by 0.9, 1.1, 1.0 times compared to that in the T0 treatment, respectively. The T1, T2 and T3 treatments significantly increased the uptake of N and P in aboveground parts of the plants, especially in grains. The T1, T2 and T3 treatments significantly increased N uptake by 1.1, 1.2, 1.2 times, increased P uptake by 0.9, 1.4, 1.6 times in early-season grains, and significantly increased N uptake by 0.8, 1.0, 1.0 times, increased P uptake by 0.7, 0.9, 0.9 times in late-season grains, compared to T0, respectively. Furthermore, T3 increased agronomic N use efficiency (AEN) and agronomic P use efficiency (AEP) by 71.1% and 69.2% in early rice plants, increased AEN and AEP by 26.4% and 25.0% in late rice plants, whereas T3 decreased total dissolved N (DN) by 16.0% in comparison with T1. Dissolved inorganic N loss in surface runoff occurred mainly in the form of NO3--N (nitrate N) under different water and fertilizer regimes. However, there were no significant differences in AEN and AEP between T2 and T3 treatments. These findings suggested that optimal applications of water and fertilizers (T3) might increase N and P uptake in rice plants, maintain yield, and reduce N loss, especially in the form of NO3--N in surface water from early rice field. In general, this study could provide theoretical support for the optimization of irrigation and fertilization and for the control of N and P non-point source pollution from the double cropping rice paddy fields in eastern Fujian Province.为优化双季稻水肥管理措施,在福建省东部双季稻区设置田间径流小区试验,研究了T0(对照,未施肥+常规灌溉)、T1[习惯施肥(273 kg N·hm-2, 59 kg P·hm-2, 112 kg K·hm-2)+常规灌溉]、T2[优化施肥(240 kg N·hm-2, 52 kg P·hm-2, 198 kg K·hm-2)+常规灌溉]和T3(优化施肥+节水灌溉)4种水肥耦合处理下双季稻产量、养分吸收利用及田面水氮、磷流失变化。结果表明: 与T0相比,T1、T2和T3处理早稻稻谷产量显著提高了0.7、1.0和1.1倍,晚稻稻谷产量显著提高了0.9、1.1和1.0倍;T1、T2和T3处理早、晚稻植株地上部分,尤其稻谷氮、磷吸收量增加显著,早稻稻谷氮吸收量分别增加1.1、1.2和1.2倍,磷吸收量增加0.9、1.4和1.6倍,晚稻稻谷氮吸收量增加0.8、1.0和1.0倍,磷吸收量增加0.7、0.9和0.9倍。T3比T1处理早稻氮、磷肥农学利用率分别显著增加71.1%和69.2%,晚稻分别显著增加26.4%和25.0%,但田面水可溶性总氮流失量减少了16.0%,并以硝态氮流失为主;T2与T3处理早晚稻氮、磷肥农学利用率差异均不显著。本试验中的优化水肥管理措施(T3)既能促进水稻氮、磷吸收利用,提高双季稻产量,又能降低早稻田面水氮素尤其是硝态氮的流失。本研究可为福建省东部双季稻区水肥利用管理和氮、磷面源污染防治提供理论支持。.
To understand the role of microorganisms in litter decomposition and nutrient cycling in volcanic forest ecosystem, we conducted in-situ litterbag decomposition experiment and used Illumina MiSeq high-throughput sequencing to analyze the response of bacterial community structure and diversity during the decomposition of litters from Larix gmelinii, Betula platyphylla and Populus davidiana, the dominant tree species in volcanic lava plateau of Wudalianchi. The results showed that mass remaining percentage of litters of three species after 18-month decomposition was 63.9%-68.1%. Litter of B. platyphylla decomposed the fastest, with significant difference in N, C:N, and N:P before and after decomposition. The richness of bacterial species and diversity index differed significantly among the three litters. Proteobacteria, Actinomycetes, and Bacteroidetes were the dominant bacterial groups at the phylum level, while Rhizobium, Sphingomonas, and Pseudomonas were the dominant groups at the genus level, with significant difference among the three litters. After 18 months, the dominant bacterial groups in litter tended to be consistent with those in volcanic lava platform soil. In the volcanic forest ecosystem, bacterial diversity and community structure were mainly affected by P, C:N, and N:P in the litter.为了解火山森林生态系统中微生物在凋落物分解和营养循环中的作用,以五大连池火山熔岩台地森林优势树种落叶松、白桦、山杨为研究对象,采用凋落物袋野外原位分解和高通量测序方法,分析细菌群落结构及多样性对凋落物分解的响应。结果表明: 经过18个月的分解,3种植物叶片凋落物质量残留率为63.9%～68.1%,白桦叶片凋落物分解最快,分解前后的N含量、C∶N、N∶P存在显著差异。3种植物叶片凋落物的细菌物种数和多样性指数具有显著差异。变形菌门、放线菌门、拟杆菌门为优势菌门,根瘤菌属、鞘氨醇单胞菌属、假单胞菌属为优势菌属,且在3种凋落物间存在显著差异。分解18个月后,凋落物中优势细菌类群与火山熔岩台地土壤趋向一致,火山森林生态系统中凋落物细菌多样性和群落结构受到凋落物中P含量、C∶N和N∶P的影响。.
Drought is one of the most devastating effects that severely reduce plant growth and development worldwide. In recent years, the availability of a reference Paulownia genome sequence has made it easier to explore gene expression, transcriptional regulation, and posttranscriptional regulation in Paulownia species. Here, we combined the analyses of the transcriptome, small RNAs, and degradome of Paulownia tomentosa seedlings to generate a comprehensive resource to describe the links between key regulatory miRNA-target gene pairs and drought stress. A total of 22,904 differentially expressed genes, 2073 differentially expressed miRNAs, and 198 target genes were identified by deep sequencing. Gene ontology function and KEGG pathway analyses of the differentially expressed genes and the target genes of the differentially expressed miRNAs revealed that momilactone A synthase, 14-3-3 protein, serine/threonine-protein kinase CTR1, and polyphenol oxidase, as well as alternative splicing, were associated directly or indirectly with drought stress in P. tomentosa. Our results will help to pave the way for further genomic studies, not only on P. tomentosa but also on other plants in family Paulowniaceae.
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