Advanced Agrochem最新文献

The gene editing and synthetic biological tools have led to the implementation of diverse metabolic engineering approaches to enhance the production of specific enzymes. Microbial keratinases can convert keratin wastes into valuable compounds for mankind. Since the market for keratinases cannot be satisfied by production from wild hosts, it is obligatory to develop hosts with high keratinase yields. The intention of this review is to evaluate microbial keratinase advancement through protein engineering, breeding techniques, and fermentation optimization. The main aim of protein engineering is to improve the heat resistance ability and catalytic activity of keratinases by employing mutagenesis methods. Moreover, modifying the expression elements and host engineering are also two unique ways to augment the keratinase yield. Intending to accelerate the production of modified keratinase, this review attempts to highlight the optimization of expression elements, such as promoter engineering, UTR, signal peptide, and codon optimization. Moreover, the approaches of host engineering including strengthening precursor supply, membrane surface engineering, and optimization of secretion pathways were also explained here. Furthermore, it is also essential to optimize the medium composition and fermentation condition for high keratinase yield. This review also addressed the present advancements, difficulties, and tendencies in the field of microbial keratinase production, along with its potential.

To find new pesticide candidates, by using of a natural product andrographolide as the precursor, a series of novel indolo[2,3-b]andrographolide derivatives were semisynthesized by Fischer-indole rearrangement reaction. Their structures were identified by ¹H NMR, IR, mp, and HRMS, and the steric configuration of compound Ic was further determined on single-crystal analysis. Compounds If and IIb showed 5.9 and 7.0 times potent acaricidal activity compared to andrographolide against Tetranychus cinnabarinus. Compound Ib displayed 4.2 folds higher aphicidal activity compared to andrographolide against Eriosoma lanigerum. In addition, the pronounced insecticidal activity of compound IIc against Aphis citricola was 4.2 folds of that of andrographolide. Scanning electron microscopy revealed that compound IIb can destroy the epidermis of T. cinnabarinus. These results can provide a basis for future research on botanical agrochemicals.

Pesticides are typically used excessively to ensure crop yields due to their low utilization extent, which can exert pressure on the environment and cause adverse effects on non-target species as well as pose a threat to human health. Hence, reducing the potential risks due to excessive pesticide use is an important goal of agriculture and environmental policies worldwide. The low pesticide utilization efficiency is attributed to poor droplet deposition on plant surfaces as well as weak interaction between pesticide and plant surfaces. In the past decades, considerable efforts have been put into solving these problems. However, a number of key challenges still remain to be addressed for the practical application. In this paper, we outline the development of a range of methods for improving the retention of pesticide on plant leaves. We also discuss and highlight several key issues that merit more attention in the future.

Given the development of insects’ resistance and deteriorative ecological environment, the discovery of insecticides with a new mode of action has been proven to be an important tool for comprehensive pest management. Herein, a novel anthranilic diamides containing 3,5-dichloropyridylpyrazole group were designed and synthesized. Their insecticidal potency was assayed against beet armyworm (Spodoptera exigua). Moreover, the structure-activity relationship of these new compounds was also discussed. Of them, compound 15g exhibited potential insecticidal activity. Because of the excellent efficacy against a series of Lepidoptera and low toxicity to mammals, compound 15g, namely tetrachlorantraniliprole, has been developed and launched into the market as an insecticide.

The discovery of novel botanical pesticides as a preferred alternative to synthetic pesticides is regarded as an environmentally friendly strategy, yet it remains a great challenge due to limited insights into the synthesis and accumulation of active ingredient intermediates. Herein, we demonstrate the use of gold nanoparticle (AuNP)-assisted laser desorption/ionization mass spectrometry imaging (LDI-MSI) for the tissue-specific distribution and spatiotemporal accumulation effect of rotenone and active ingredient intermediates in its biosynthetic pathway within the roots of Derris elliptica. The MSI results revealed that rotenone was mainly concentrated in the epidermis, cortex, and xylem in the first two years and began to accumulate in the phloem since the 3rd year. Meanwhile, the rotenone contents increased in the epidermis, cortex, and xylem in the 4th year and finally decreased in the 5th year. The ultra-performance liquid chromatography (UPLC) results revealed that there was a significant difference in rotenone content between the root and non-root bark (p < 0.05) except for the 1st year. It reached its maximum value at 9.71% in the root bark in the 4th year and 7.98% in the non-root bark in the 1st year, which was in accordance with the MSI results. Additionally, the active ingredient intermediates in the Hydroxylation/Methylation and Rotenoid Phases of the biosynthetic pathway of rotenone were concentrated in the root region. Taken together, the collective results provide the scientific guidance for the scientific cultivation of D. elliptica and the efficient extraction of botanical pesticides.

Silver nanoparticles (AgNPs) are extensively utilized in industrial, biotechnological and medical fields because of their specific physical and chemical properties, which shown small size effects, surface and interface effects, quantum scale effects. Inevitably, wastewater containing AgNPs is leached into the soil. AgNPs in soil may be absorbed by plant roots and they affect plant growth. Understanding the complex interactions between AgNPs and plants is of crucial significance since plants are essential to the ecological environment as key players in ecosystems. Most previous reports have focused on AgNP phytotoxicity rather than positive effects in the plant field. This article reviews recent studies on the important aspects about nanoparticles including the green synthesis, absorption, migration, accumulation, biotransformation, biological effects, and the underlying molecular mechanisms of AgNPs affecting plants. We provide insights into the interactions between AgNPs and plants, helping to further understand AgNP-related effects and biosafety in agricultural production, as well as the practical application of various nanomaterials in agriculture.

A novel fluorescent probe based on 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) structure as fluorophore with 7-nitro-1,2,3-benzoxadiazole (NBD) served as detection unit was designed for specific and sensitive detection of H₂S in living cells and zebrafish. In this work, we prepared a novel fluorescent probe for detection of hydrogen sulfide with strong fluorescent enhancement, good biocompatible and excellent specifically detection. The probe 1 displayed emission at 580 nm with excited wavelength at 530 nm in aqueous solution which organic proportion was only 10%. This probe exhibits highly selectively and specifically to detect H₂S compared with other related interferences including sulphur-amino acids, sulfite ion and cations. In the addition of H₂S into the detection system, the fluorescent intensity was sharply increased about 170-fold with the limitation detection as low as 16.8 nM. The sensing mechanism was through the cleave reaction between analyte and NBD unit which was characterized by high resolution mass spectrum (HRMS). This platform also permits low biotoxicity which can successfully be utilized to evaluate the concentration level of H₂S and imaging in living cells and zebrafish.

Se-chitosan with a high Se content of 139 mg/g was successfully synthesized using the glacial acetic acid-sodium selenite (HAc-Na₂SeO₃) method. The chemical structure of Se-chitosan was characterized by FTIR, XRD, TGA, UV–vis and ¹³C NMR, confirming that selenite acid was introduced into chitosan via the esterification reaction of the hydroxyl group at C6 and the electrostatic interaction of the amino group at C2 of chitosan. Agarose hydrogels were designed as an efficient carrier of Se-chitosan for Se-enriched cultivation of sprouts. The hydrogels exhibited a porous structure, which is beneficial for Se diffusion in hydrogels. The growth indexes of sprouts grown in Agar/Se-chitosan composite hydrogels with different Se concentrations, including plant weight, plant height and Se content, were investigated. The results showed that in the Se-enriched cultivation of sprouts, Se-chitosan possessed an excellent Se enrichment effect. As the Se concentration in Agar/Se-chitosan composite hydrogels increases from 0 to 1600 μg/L, the Se content of the sprouts will also increase from 0.92 mg/kg to 6.79 mg/kg accordingly. Moreover, it is necessary to control the amount of Se-chitosan added to the hydrogels; otherwise, the growth of sprouts will be inhibited. This research provided a simple and effective method for the fabrication of Se-containing hydrogels for Se-enriched cultivation of sprouts.

Multitarget insecticides are more likely to achieve comprehensive regulation of insects with a low risk of resistance. Insect chitinolytic enzymes, including GH18 chitinases and GH20 β-N-acetyl-d-hexosaminidase, are attractive targets for multitarget insecticide design by virtue of their similar substrate binding mode and catalytic mechanism. On the other hand, natural products with diverse skeletal structures are potential repositories of chitinolytic enzyme inhibitors. This minireview first presents the theoretical basis of developing multitargeted inhibitors against insect chitinolytic enzymes and then focuses on the progress in developing multitarget inhibitors derived from natural products. These may provide ideas for the exploitation of novel pesticide leads from natural products by targeting multiple targets.

Crops will be harmed by fungi, pests and weeds during their growth. In the past half century, scientists have conducted in-depth research on natural products extracted from microorganisms, plants or animals, and used natural products and their derivatives as the lead for pesticides discovery. Natural product pesticides have the advantages of easy degradation in the environment, selective control and safety to non-target organisms. This review summarizes the studies on natural products pesticides in recent years, including natural products of chemical modification and biosynthesis, mainly fungicides, herbicides, insecticides and acaricides. We classify natural products according to their active fragments, and discuss their effects on the control of agricultural fungi, pests and weeds. Ultimately, we found that lead discovery based on natural products has great advantages in pesticide development.