Chemical and Biological Technologies in Agriculture最新文献

Background

The effects of blue light on photosynthetic organs have been studied. However, its effects on non-photosynthetic organs, in particular, on the early stages of rice caryopsis development, are unclear. Thus, we aimed to determine the metabolic characteristics of caryopsis development under blue light to improve the metabolic quality of crop kernels.

Results

We conducted a multi-omics analysis of each of the three periods from the beginning of cellular differentiation to the end of morphogenesis in post-pollination seeds of a japonica rice variety to explore the effect of blue light on metabolic levels during these metabolic changes and its genetic basis. It was found that blue light caused a gradual decrease in auxin content, a significant increase in the accumulation of JA and flavonoids, and a downregulation of the expression of many starch-related genes and proteins, leads to reduced starch synthesis and smaller starch granules. In addition, the gene co-expression network identified three transcription factors that may regulate starch and two that may regulate flavonoids.

Conclusions

It was found through multi-omics testing that hormones such as jasmonic acid and auxins, and metabolites including alkaloids, flavonoids, lipids, organic acids, phenolic acids, and terpenoids altered significantly. Transcriptome and proteome analyses showed that blue light affected the seed nutrient repository activity. Specifically, starch- and gluten-related genes and proteins were significantly downregulated. Co- and WGCNA analyses identified several transcription factors that were regulated under blue light and identified key regulators of starch. Our study provides an understanding of the effects of blue light on post-flowering development in Gramineae and provides a framework for blue light-induced synthesis of secondary metabolites.

Graphical Abstract

Background

Escherichia coli is an integral part of the colonic microflora, though its pathogenic intestinal strains can contaminate animal and plant products and cause significant challenges in the food industry. Thermal processing is one of the most common methods used to preserve food. Nevertheless, non-thermal antibacterial methods, such as antibacterial blue light (aBL), are attracting more interest due to the growing demand for minimally processed products. Thus, the current study was aimed at assessment whether the risk of co-selection for these two food processing approaches exist.

Results

The development of E. coli tolerance to both selective factors was observed after repeated exposure to sublethal doses of heat and aBL, and the observed adaptations were confirmed to be phenotypically stable. The results demonstrated that populations with increased tolerance to aBL also exhibited increased tolerance to temperature, while the sensitivity of temperature-tolerant populations to aBL did not change. We also identified 11 genes that could be involved in cross-stress tolerance. Neither adaptation changed the antibiotic sensitivity of the tolerant strains. Finally, short- and long-term pre-incubation at elevated temperatures significantly increased the tolerance of E. coli BW25113 to aBL.

Conclusions

The results obtained clearly demonstrate that aBL may serve as a complementary approach in food industry lacking resistance development and exerting no impact on microbial drug susceptibility. Nevertheless, the phenomenon of cross-tolerance should be considered an issue when designing food processing including sequential use of aBL and high temperature.

Graphical Abstract

Background

Dissolved organic matter (DOM) plays a significant role in the biogeochemical cycle of crucial elements in aquatic ecosystem. However, it is still not clear on the spectral characteristics of water DOM in different types of alpine wetlands, which have less anthropogenic influences and intensive ultraviolet radiation. Here, we collected 107 water samples from marsh, lake, and river wetlands in the Zoige plateau, China, and analyzed the chemical characteristics, compositions, and potential sources of chromophoric DOM by combining UV–vis spectroscopy and excitation–emission matrix fluorescence spectroscopy coupled with parallel factor analysis (EEMs-PARAFAC).

Results

UVC and UVA fulvic-like substances were the prevailing fluorescence components in water DOM, which accounted for 23.74–71.59% and 16.76–30.01% of the total fluorescence intensity, respectively. Compared with the lake and river wetlands, fluoresce intensities of UVC and UVA fulvic-like substances in DOM were higher in marsh wetland. Marsh wetlands possessed the highest SUVA₂₅₄, E2/E3, E2/E4, and E4/E6 of DOM, suggesting higher humification degree, higher relative molecular nominal size, and higher aromaticity. And the E2/E4 ratios in most water samples were higher than 12, indicating water DOM was mainly derived from autochthonous sources in alpine wetlands.

Conclusions

Wetland types strongly affected the spectral characteristics of water DOM in Zoige plateau. These findings may be beneficial for sustainable management of alpine wetlands.

Graphical Abstract

Background

Neonicotinoids are widespread insecticides because of their potent effects against aphids and other piercing-sucking insects in addition to having high selectivity toward insects rather than vertebrates. However, they affect severely some non-target insects, mainly honeybee in a phenomenon called colony collapse disorder (CCD).

Results

Effects of imidacloprid (IMI), most used neonicotinoids, on aphid acetylcholinesterase (AChE), in vivo and in vitro were examined; besides, molecular modeling was used to investigate similarities and differences of AChE and nicotinic acetylcholine receptors α1-subunit (nAChRα1) in aphids, target insect, and honeybees, non-target insect. Results showed that aphid AChE was inhibited in vitro, with IC50 108.6 mg/L but not affected in vivo while the mortality was concentration-dependent with high toxicity (LC50 9.50 mg/L); in addition, aphid AChE was more inhibited, in vitro, but with much less effects, in vivo, than that of honeybees. These results indicate that AChE is not the main cause of the observed mortality, but it still has a role in insect resistance system with different responses in both insects. Molecular modeling showed high similarity in primary and secondary structures of AChE indicated by high identity (67%) and low gaps (1%); besides, the same template for both enzymes was auto-selected for homology. In addition, similar positions of the triad amino acids were found in AChE of both insects indicating high similarity. Conversely, the similarity in nAChRα1 in both insects is lower (50% identity and 9% gaps). These gaps (50 amino acids) are found in the intracellular large loop between TM3 and TM4 and account for the observed differences in the nAChRα1 binding sites of in both insects.

Conclusion

These observed variations in nAChRα1 structures and binding sites in different insect species can be used as good bases in designing new neonicotinoids that express high effects on target insects with better selectivity to minimize adverse effects on non-target organisms.

Graphical Abstract

Background

The discovery of new lead compounds with desired properties and biological activity is an excellent challenge in pesticide chemistry. Chloroacetamide are an important class of synthetic herbicides.

Results

To explore the herbicidal activity of chloroacetamides, several new chloroacetamide derivatives have been designed, and synthesized. The compounds have been described by forming Schiff bases followed by chloroacetylation of imines. The herbicidal activity as a chlorophyll inhibition was evaluated against two broadleaf weeds (Chenopodium album and Anagallis arvensis) and two grass weeds (Lolium temulentum and Echinochloa crus-galli) in comparison with acetochlor as a standard herbicide. ¹H-NMR, ¹³C-NMR and mass spectroscopic analyses confirmed the chemical structures of the synthesized compounds. Several compounds have demonstrated highly potent herbicidal activity compared to the standard herbicide acetochlor. Some of them have been described as the most effective against weeds tested, such as compounds 5b and 18b. Molecular docking to the active sites of Very Long Chain Fatty Acid Synthase (VLCFAS) has indicated that most compounds are low-energy binding agents and show high affinity for the active pocket.

Conclusion

Novel herbicides may be discovered by combining chloroacetamide derivatives with these existing lead structures.

Graphical Abstract

Background

Plant-derived antimicrobials (PDAs) are considered a viable alternative to synthetic antimicrobial agents. Diverse antimicrobial mechanisms of PDAs significantly reduce the risk of developing antimicrobial resistance. Utilization of PDAs also offers economic and environmental advantages, as they can be derived from agricultural byproducts, such as olive pomace.

Results

In this study, a green, water-based, ultrasound-assisted extraction (UAE) was deployed to obtain aqueous olive pomace extract (OPE) from dry olive pomace. Total phenolic content, extraction yield, chemical compositions, and antimicrobial activities of OPE were evaluated. In addition, the potential synergistic interaction between the phenolic components in OPE and the antimicrobial mechanisms underlying the synergistic interaction were characterized. The results show that ca. 25 mg GAE/g of extraction yields were achieved by the UAE of dry olive pomace. Based on the high-performance liquid chromatography (HPLC) analysis, diverse phenolic compounds such as gallic acid (GA), hydroxytyrosol (HT), and 4-hydroxyphenylacetic acid (4-HPA) were identified in OPE. OPE exhibited strong antimicrobial activities, and 0.2 mg GAE/mL of OPE achieved > 5 log reductions of Escherichia coli O157:H7 and Listeria innocua cells within 30 min of treatment. A 3D isobologram analysis demonstrated that OPE exhibited strong synergistic antimicrobial activities, compared to those of individual phenolic components (GA, HT, or 4-HPA), showing interaction index (γ) of 0.092 and 0.014 against E. coli O157:H7 and L. innocua, respectively (γ < 1: synergistic activity). Antimicrobial mechanism analyses revealed that phenolic components in OPE exerted strong synergistic activities through diverse modes of action, and increased levels of oxidative stress, membrane damage, and decreased levels of metabolic activities were observed in the OPE-treated bacterial cells.

Conclusions

These findings demonstrate an approach for valorizing agricultural byproducts to develop plant byproduct-based antimicrobials with strong synergistic activities. Multiple modes of action of this byproduct extract may enable the control of diverse microbes in food and agriculture systems.

Graphical abstract

Background

The chestnut blight fungus, Cryphonectria parasitica, and its Cryphonectria hypovirus 1 (CHV1) comprise a useful model system to study fungus–virus interactions. CHV1 infection results in various phenotypic changes in the fungal host, including hypovirulence and other associated symptoms. Many studies have investigated the effects of hypoviral infection and how this infection affects physiological and biochemical states: however, no studies have examined volatile organic compounds (VOCs).

Results

This study characterized the global profile of VOCs released from C. parasitica, and by comparing CHV1-free with CHV1-infected isogenic strains, proved that CHV1 infection significantly affects the composition and levels of VOCs. We demonstrated that these VOC alterations were caused by viral regulation of the expression of fungal genes encoding enzymes responsible for the production of VOCs. The changed VOC profile resulting from CHV1 infection was more attractive to insects than the VOC profile from the virus-free strain, suggesting differences in the efficacy of fungal dissemination by the insect vector.

Conclusions

We characterized VOCs from C. parasitica and demonstrated that mycovirus (CHV1) infection affects fungal VOCs. We provided evidences that these alterations are caused by the modulation of the corresponding gene expression by CHV1 and resulted in changes in attractiveness to insects, suggesting the improved efficacy of hypovirulent C. parasitica for insect-borne dissemination.

Graphical Abstract

Background

Phytosulfokine (PSK) functions as a plant peptide growth factor that plays important and diverse roles in plant development and stress responses. Nevertheless, PSKs have not been systematically analyzed in wheat.

Results

A genome-wide comparative analysis of PSK genes in wheat was conducted and 15 TaPSKs were identified and divided into four subgroups in the wheat genome based on sequence similarity. The examination of motif compositions of TaPSK genes revealed the presence of the YIYTQ signature motif in the C-terminus of all TaPSK polypeptide precursors, with a highly conserved feature across different species. Exogenous application of TaPSK peptide promoted root growth in wheat. Quantitative RT-PCR analysis revealed that the TaPSKs exhibited preferential or tissue-specific expression patterns in wheat. In particular, three homologs of the TaPSK1 genes were specifically expressed in grains, with the strongest expression observed in the developing grains at 15 days after anthesis. Compared with wild type, transgenic rice lines overexpressing TaPSK1-A exhibited larger grain size and higher thousand-grain weight. The promoter region and genomic sequence of the wheat TaPSK1-A gene were cloned. Sequence polymorphism showed that five single-nucleotide polymorphisms (SNPs) were identified in the promoter region of TaPSK1-A. A Kompetitive Allele-Specific PCR (KASP) marker was developed for TaPSK1-A based on –806 bp SNP (C/T transition), and two haplotypes, TaPSK1-A-HapI and TaPSK1-A-HapII were detected in 260 wheat accessions collected from different regions. The expression of TaPSK1-A, promoter activity, and thousand-grain weight (TGW) in the TaPSK1-A-HapII haplotype were higher than those in the TaPSK1-A-HapI haplotype. Furthermore, yeast one-hybrid assays revealed the binding of TaNF-YB1 and TaERF39 to the promoter regions of the TaPSK1-A gene, and TaMADS29 could bind to the promoters of TaPSK1-B and TaPSK1-D genes.

Conclusions

Comparative genome-wide analysis of TaPSK peptide family revealed that the TaPSK1 gene is involved in wheat grain development, and the developed TaPSK1-A-KASP marker could be utilized for marker-assisted selection breeding of wheat.

Graphical Abstract

Background

Salvia miltiorrhiza Bunge, a significant and widely used medicinal herb, is also recognized in the US Pharmacopoeia as a dietary supplement. However, the decline in yield and quality limits its further development as a traditional herbal medicine. Therefore, a deeper understanding of how synthetic communities (SynCom) affect the quality and yield of S. miltiorrhiza and the underlying mechanisms is necessary.

Results

In this study, we selected S. miltiorrhiza as the research subject and designed two synthetic communities (SynCom 1 and SynCom 2) using five endophytic fungi without significantly growth-promoting effect. We conducted both greenhouse and field experiments to investigate their impact on the yield and quality of the herbal plants. Greenhouse experiments confirmed that SynCom 1 significantly increased the biomass of S. miltiorrhiza, whereas SynCom 2 had the opposite effect. Field experiments further demonstrated that the application of SynCom 1 promoted photosynthesis and enhanced carbon and nitrogen metabolism, steady and markedly promoted plant growth, and thus increased S. miltiorrhiza yield compared to the uninoculated. In contrast, SynCom 2 inhibited yield but increased the content of the main active components. Un-targeted metabolomics analysis showed that SynCom 1 mainly promoted tricarboxylic acid cycle and nitrogen assimilation process to increase yield, and SynCom 2 mainly increase substrate content in the salvianolic acid and tanshinone synthesis pathways to improve quality.

Conclusion

These beneficial qualities exhibited by SynComs composed of fungi without apparent growth-promoting abilities represent an untapped resource that can be leveraged to enhance crop productivity. This opens up new research avenues for precision manipulation of plant microbiomes.

Graphical abstract

Background

Rose flowers contain active ingredients such as flavonoids and volatile oils and are acknowledged to be good natural resources owing to their anti-aging and antioxidant properties. In this study, we develop four new rose varieties (named Ever-rose) that are fragrant, pest resistant, and easy to grow. Subsequently, we evaluate the properties of Ever-rose and its potential for use in anti-aging products.

Methods

The chemical composition of Ever-rose was determined using ultra-high-performance liquid chromatography triple time-of-flight mass spectrometry/mass spectrometry. The antioxidant activity of the Ever-rose extract was evaluated using various assays, including superoxide dismutase activity, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity, and xanthine oxidase activity. The variations in proteolytic matrix metalloproteinase-1 expression, collagen content after ultraviolet (UV) irradiation, and reactive-oxygen-species (ROS) levels after infrared A (IRA) treatment were evaluated. The variations in cell elasticity were assessed via atomic force microscopy.

Results

The petal extracts of Ever-rose (named ER004(P), ER011(P), ER012(P), and ER015(P)) showed good antioxidant activity. They effectively inhibited UV irradiation-induced MMP-1 expression and IRA irradiation-induced increase in mitochondrial ROS levels. Additionally, they inhibited variations in cell shape and elasticity as aging progressed. In particular, ER011(P) demonstrated the best anti-aging and antioxidant effects.

Conclusion

The newly developed Ever-rose showed excellent antioxidant and anti-aging effects. In particular, ER011(P) demonstrated the best properties owing to its high antioxidant content. Hence, it exhibits significant potential as a functional cosmetic ingredient.

Graphical Abstract