Developing Global Leaders for Research, Regulation, and Stewardship of Crop Protection Chemistry in the 21st Century

Mining of Minor Disease Resistance Genes in V. vinifera Grapes Based on Transcriptome

Intraspecific recurrent selection in V. vinifera is an effective method for grape breeding with high quality and disease resistance. The core theory of this method is the substitution accumulation of multi-genes with low disease resistance. The discovery of multi-genes for disease resistance in V. vinifera may provide a molecular basis for breeding for disease resistance in V. vinifera. In this study, resistance to downy mildew was identified, and genetic analysis was carried out in the intraspecific crossing population of V. vinifera (Ecolly × Dunkelfelder) to screen immune, highly resistant and disease-resistant plant samples; transcriptome sequencing and differential expression analysis were performed using high-throughput sequencing. The results showed that there were 546 differential genes (194 up-regulated and 352 down-regulated) in the immune group compared to the highly resistant group, and 199 differential genes (50 up-regulated and 149 down-regulated) in the highly resistant group compared to the resistant group, there were 103 differential genes (54 up-regulated and 49 down-regulated) in the immune group compared to the resistant group. KEGG analysis of differentially expressed genes in the immune versus high-resistance group. The pathway is mainly concentrated in phenylpropanoid biosynthesis, starch and sucrose metabolism, MAPK signaling pathway-plant, carotenoid biosyn-thesis and isoquinoline alkaloid biosynthesis. The differential gene functions of immune and resistant, high-resistant and resistant combinations were mainly enriched in plant-pathogen interaction pathway. Through the analysis of disease resistance-related genes in each pathway, the potential minor resistance genes in V. vinifera were mined, and the accumulation of minor resistance genes was analyzed from the molecular level.

Hazard Assessment of the Effects of Acute and Chronic Exposure to Permethrin, Copper Hydroxide, Acephate, and Validamycin Nanopesticides on the Physiology of Drosophila: Novel Insights into the Cellular Internalization and Biological Effects

New insights into the interactions between nanopesticides and edible plants are required in order to elucidate their impacts on human health and agriculture. Nanopesticides include formulations consisting of organic/inorganic nanoparticles. Drosophila melanogaster has become a powerful model in genetic research thanks to its genetic similarity to mammals. This project mainly aimed to generate new evidence for the toxic/genotoxic properties of different nanopesticides (a nanoemulsion (permethrin nanopesticides, 20 ± 5 nm), an inorganic nanoparticle as an active ingredient (copper(II) hydroxide [Cu(OH)₂] nanopesticides, 15 ± 6 nm), a polymer-based nanopesticide (acephate nanopesticides, 55 ± 25 nm), and an inorganic nanoparticle associated with an organic active ingredient (validamycin nanopesticides, 1177 ± 220 nm)) and their microparticulate forms (i.e., permethrin, copper(II) sulfate pentahydrate (CuSO₄·5H₂O), acephate, and validamycin) widely used against agricultural pests, while also showing the merits of using Drosophila—a non-target in vivo eukaryotic model organism—in nanogenotoxicology studies. Significant biological effects were noted at the highest doses of permethrin (0.06 and 0.1 mM), permethrin nanopesticides (1 and 2.5 mM), CuSO₄·5H₂O (1 and 5 mM), acephate and acephate nanopesticides (1 and 5 mM, respectively), and validamycin and validamycin nanopesticides (1 and 2.5 mM, respectively). The results demonstrating the toxic/genotoxic potential of these nanopesticides through their impact on cellular internalization and gene expression represent significant contributions to future nanogenotoxicology studies.

Nanomaterials for Postharvest Management of Insect Pests: Current State and Future Perspectives

Globally, between one quarter and one-third of total grains produced each year are lost during storage mainly through infestation of insect pests. Among the available control options such as chemical and physical techniques, fumigation with aluminum phosphide (AlP) is so far considered the best control strategy against storage insect pests. However, these insect pests are now developing resistance against AIP due to its indiscriminate use due to non-availability of any effective alternative control option. Resistance to AIP among storage insect pests is increasing, and its inhalation has shown adverse effects on animals and human beings. Nanotechnology has opened up a wide range of opportunities in various fields such as agriculture (pesticides, fertilizers, etc.), pharmaceuticals, and electronics. One of the applications of nanotechnology is the usage of nanomaterial-based insecticide formulations for mitigating field and storage insect pests. Several formulations, namely, nanoemulsions, nanosuspensions, controlled release formulations, and solid-based nanopesticides, have been developed with different modes of action and application. The major advantage is their small size which helps in proper spreading on the pest surface, and thus, better action than conventional pesticides is achieved. Besides their minute size, these have no or reduced harmful effects on non-target species. Nanopesticides can therefore provide green and efficient alternatives for the management of insect pests of field and storage. However, an outcry against the utilization of nano-based pesticides is also revealed. It is considered by some that nano-insecticides may also have hazardous effects on humans as well as on the environment. Due to limited available data, nanopesticides have become a double-edged weapon. Therefore, nanomaterials need to be evaluated extensively for their large-scale adoption. In this article, we reviewed the nanoformulations that are developed and have proved effective against the insect pests under postharvest storage of grains.

Rhabdopeptides from Xenorhabdus budapestensis SN84 and Their Nematicidal Activities against Meloidogyne incognita

For decades, plant parasitic nematodes have caused serious damage to crop production. Most nematicides are banned because of their negative impacts on the environment and public health. The repeated application of the few commercially available nematicides has caused more incidences of nematicide resistance. To seek novel nematicides, seven linear peptides named rhabdopeptides I-O, 1-7, were isolated from culture broth of Xenorhabdus budapestensis SN84. The structures of the peptides were elucidated on the basis of extensive mass spectrometry (MS), and nuclear magnetic resonance analyses. 3, 4, and 7 were novel compounds. 1, 2, 5, and 6 were isolated and purified for the first time, despite being previously elucidated from an extract mixture based on labeling and MS experiments. All seven compounds were tested for their nematicidal activities against the second-stage juveniles (J2) of Meloidogyne incognita using 24-microwell plates. Rhabdopeptide J, 2, demonstrated strong inhibitory activity with an LC₅₀ value of 27.8 μg/mL. Rhabdopeptide K, 3, and M, 5, showed moderate inhibitory activity with LC₅₀ values of 46.3 and 42.4 μg/mL, respectively.

Natural α-methylenelactam analogues: Design, synthesis and evaluation of α-alkenyl-γ and δ-lactams as potential antifungal agents against Colletotrichum orbiculare

In our continued efforts to improve the potential utility of the α-methylene-γ-lactone scaffold, 62 new and 59 known natural α-methylenelactam analogues including α-methylene-γ-lactams, α-arylidene-γ and δ-lactams, and 3-arylideneindolin-2-ones were synthesized as the bioisosteric analogues of the α-methylenelactone scaffold. The results of antifungal and cytotoxic activity indicated that among these derivatives compound (E)-1-(2, 6-dichlorobenzyl)-3-(2-fluorobenzylidene) pyrrolidin-2-one (Py51) possessed good selectivity with the highest antifungal activity against Colletotrichum orbiculare with IC₅₀ = 10.4 μM but less cytotoxic activity with IC₅₀ = 141.2 μM (against HepG2 cell line) and 161.2 μM (against human hepatic L02 cell line). Ultrastructural change studies performed by transmission electron microscope showed that Py51 could cause important cell morphological changes in C. orbiculare, such as plasma membrane detached from cell wall, cell wall thickening, mitochondria disruption, a dramatic increase in vacuolation, and eventually a complete loss in the integrity of organelles. Significantly, mitochondria appeared one of the primary targets, as confirmed by their remarkably aberrant morphological changes. Analysis of structure-activity relationships revealed that incorporation of the aryl group into the α-exo-methylene and the N-benzyl substitution increased the activity. Meanwhile, the α-arylidene-γ-lactams have superiority in selectivity over the 3-arylideneindolin-2-ones. Based on the results, the N-benzyl substituted α-(2-fluorophenyl)-γ-lactam was identified as the most promising natural-based scaffold for further discovering and developing improved crop-protection agents.

Diterpenoids from Streptomyces sp. SN194 and Their Antifungal Activity against Botrytis cinerea

Botrytis cinerea is a serious phytopathogen affecting a wide range of crops around the world. Many fungicides targeting Botrytis cinerea have failed due to the pathogen's genetic plasticity. In an effort to search for new fungicides from natural products, two new diterpenoids, named chloroxaloterpin A, 1, and B, 2, were isolated from culture broth of Streptomyces sp. SN194 along with four known diterpenoids, viguiepinol, 3, and oxaloterpins C-E, 4-6. Their structures were elucidated based on extensive MS, NMR, and X-ray crystallography analyses. Both the [(2-chlorophenyl)amino]carbonyl carbanic acyl group in 1 and the 2-[(2-chlorophenyl)amino]-2-oxo-acetyl group in 2 are discovered in natural products for the first time. All six compounds were tested against Botrytis cinerea, and chloroxaloterpin A, 1, and B, 2, demonstrated strong inhibitory activity against spore germination with EC₅₀ of 4.40 and 4.96 μg/mL, respectively.

13th IUPAC International Congress of Pesticide Chemistry: Crop, Environment, and Public Health Protection, Technologies for a Changing World

This introductory paper provides an overview of Perspectives papers written by plenary speakers from the 13th IUPAC International Congress of Pesticide Chemistry held in San Francisco, CA, USA, in August 2014. This group of papers emphasizes some of the emerging issues and challenges at the forefront of agricultural research: sustainability; agriculture's response to climate change and population growth; pollinator health and risk assessment; and global food production and food security. In addition, as part of the Congress, a workshop on "Developing Global Leaders for Research, Regulation, and Stewardship of Crop Protection Chemistry in the 21st Century" identified specific recommendations to attract the best scientists to agricultural science, to provide opportunities to study and conduct research on crop protection chemistry topics, and to improve science communication skills.