We propose a Multi-Objective Shuffled Frog-Leaping Algorithm (MOSFLA) and Genetic Algorithm (GA) based task assignment and sequencing method, for multi-Unmanned Aerial Vehicles (multi-UAVs) ...plant-protection operation optimization. Based on full coverage of spray area, a dual decision model of non-operation flight distance and total operation time is developed considering energy consumption and operation efficiency. The proposed optimization method is hybridized using MOSFLA and GA: we first use modified MOSFLA for multi-UAVs operation assignment optimization, shrinking multi-UAVs operation cost including fields allocation, non-operation flight distance and operation time difference; we then employ GA for fields operation sequencing optimization, reducing the total operation time. Considering multi-UAVs’ take-off preparation delay effect, we established a latency time calculation model to determine total operation time for multi-UAVs. The test results show that: ① the non-operation flight distance cost for multi-UAVs using MOSFLA is less than that of single-UAV, which also performs better than that for multi-UAVs in traditional modes; ② the total operation time shrinks by using GA with known assignment matrix (including MOSFLA), which could save over 20 min compared with traditional modes; ③ the total operation time cost in MOSFLA–GA is less than that in traditional modes and optimized traditional modes, with same UAV number and preparation time for take-off; ④ the minimum iteration when assignment fitness value of MOSFLA attains maximum is small (< 20); the minimum iteration when sequencing fitness value of GA attains maximum is less than 100, but is 5 in certain cases.
•Non-operation flight distance and operation time difference could be decreased using hybrid algorithm based on Multi-Objective Shuffled Frog-Leaping Algorithm (MOSFLA).•In consideration of lacking in labor for take-off preparation of multi-UAVs, the optimized operation sequencing generated by Genetic Algorithm (GA) could save more than 20 min compared with traditional methods.•Using MOSFLA-GA could save non-operation flight distance and total operation time both.•As UAV number increases, total operation time decreases but the decrease rate shrinks due to the lack of labor.
Hidden ingredients in plant protection products (PPPs) threaten public health, food trade, and the environment. In this study, we developed a high-throughput screening method of 639 hidden ...ingredients in PPPs using GC-MS/MS in multiple reaction monitoring mode. Results showed that the qualitative criteria of retention time (tR) shift and uncertainty of qualifier to quantifier ratio in the commercially available Shimadzu Smart Pesticides Database were set at < 0.17 min and < 30%, respectively, which could be used to tentatively identify compounds without standards. The limits of quantification were 0.01–0.05 mg/kg. A wide linear range of 10–1000 μg/L was observed with R2 ≥ 0.975. Recoveries from three types of PPP formulations were 62.08%− 126.3%, with relative standard deviations < 15.7%. Finally, this method was applied to screen and quantify hidden ingredients in 91 plant protection products (PPPs) samples collected from online sales in China. Only one hidden ingredient, dimethomorph (1.6 g/kg), was detected in the polyoxin formulation (15% wettable powder). The results will be helpful in assessing the potential risks of hidden ingredients in PPPs.
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•A high-throughput screening method for 639 hidden ingredients was established.•Qualitative criteria were set based on ion ratio and retention time shift.•91 plant protection products of three types of formulations were investigated.•One hidden ingredient dimethomorph was detected in biopesticide products.
This paper reviews the impact of beer-making stages (malting, mashing, boiling, and fermentation) on the behavior of pesticide residues. The large use of pesticides on barley and hop could cause the ...occurrence of their residues in beer. The foremost factors influencing the stability of residues (pH, temperature, and water content) and the physical-chemical properties of pesticides (octanol–water partition coefficient, vapor pressure, and water solubility) are essential to know their final fate. Most pesticides show a decrease in the unhopped wort because they are adsorbed onto the spent grains after mashing. In addition, their concentrations decrease during boiling and fermentation. Generally, maltsters should dedicate particular attention to the residues of hydrophobic pesticides because they can remain on the malt. Contrarily, brewers should control residues of hydrophilic pesticides because they can be carried over into young beer, disturbing the quality and organoleptic properties (flavor, aroma, taste, or color) of the beer.
Being sessile, plants are subjected to a diverse array of environmental stresses during their life span. Exposure of plants to environmental stresses results in the generation of reactive oxygen ...species (ROS). These activated oxygen species tend to oxidize various cellular biomolecules like proteins, nucleic acids, and lipids, a process that challenges the core existence of the cell. To prevent the accumulation of these ROS and to sustain their own survival, plants have developed an intricate antioxidative defence system. The antioxidative defence system comprises various enzymatic and nonenzymatic molecules, produced to counter the adverse effect of environmental stresses. A sizable number of these molecules belong to the category of compounds called secondary metabolites. Secondary metabolites are organic compounds that are not directly involved in the growth and development of plants but perform specialized functions under a given set of conditions. Absence of secondary metabolites results in long-term impairment of the plant’s survivability. Such compounds generally include pigments, phenolics, and so on. Plant phenolic compounds such as flavonoids and lignin precursors have been reported to accumulate in response to various biotic and abiotic stresses and are regarded as crucial defence compounds that can scavenge harmful ROS. Another important category of plant metabolites, called brassinosteroids, exhibit stress regulatory and growth-promoting activity and are classified as phytohormones. Elucidation of the physiological and molecular effects of secondary metabolites and brassinosteroids have catapulted them as highly promising and environment-friendly natural substances, suitable for wider application in plant protection and crop yield promotion. The present review focuses on our current understanding of how plants respond to the generation of excessive ROS and the role of secondary metabolites and brassinosteroids in countering the adverse effects of environmental stresses.
A biostimulant is an organic material that, when applied in small quantities, enhances plant growth and development such that the response cannot be attributed to the application of traditional plant ...nutrients. This review is aimed at highlighting developments in the processing of macroalgae for agricultural biostimulants (AB), summarising the biologically active components of brown macroalgae and examining the factors supporting the use of macroalgal AB for managing abiotic and biotic stresses in crop plants. The policy drivers supporting the use of macroalgal-derived ABs in agriculture are also emphasised. We examine the use of macroalgal ABs in crop production and evaluated the benefits of seed priming, foliar application, soil drenches and hydroponic treatments. The use of macroalgal ABs on crop plants can generate multiple benefits with reported effects including enhanced rooting, higher crop and fruit yields, freezing, drought and salt tolerance, enhanced photosynthetic activity and resistance to fungi, bacteria and virus. ABs can be applied as an alternative, or used in conjunction with synthetic crop protection products and plant growth regulators, and may have a role in maintaining crop production levels, health and quality in the future when many active ingredients will be lost to the industry due to changes in European Union regulations. Worldwide, macroalgae remain largely unexploited, we highlight some of the future research and development priorities.
Turning Meristems into Fortresses Périlleux, Claire; Bouché, Frédéric; Randoux, Marie ...
Trends in plant science,
05/2019, Volume:
24, Issue:
5
Journal Article, Web Resource
Peer reviewed
TERMINAL FLOWER1 (TFL1) was named from knockout Arabidopsis thaliana mutants in which the inflorescence abnormally terminates into a flower. In wild type plants, the expression of TFL1 in the center ...of the inflorescence meristem represses the flower meristem identity genes LEAFY (LFY) and APETALA1 (AP1) to maintain indeterminacy. LFY and AP1 are activated by flowering signals that antagonize TFL1. Its characterization in numerous species revealed that the TFL1-mediated regulation of meristem fate has broader impacts on plant development than originally depicted in A. thaliana. By blocking floral transition, TFL1 genes participate in the control of juvenility, shoot growth pattern, inflorescence architecture, and the establishment of life history strategies. Here, we contextualize the role of the TFL1-mediated protection of meristem indeterminacy throughout plant development.
TERMINAL FLOWER1 (TFL1) was discovered from forward genetic studies in Arabidopsis thaliana and was found to regulate inflorescence indeterminacy by mutual repression of the floral meristem identity genes LEAFY (LFY) and APETALA1 (AP1). Recent analyses indicated that LFY rather acts as an activator of TFL1 and only indirectly represses TFL1 through AP1.
A growing body of evidence demonstrates that TFL1 not only controls inflorescence architecture but also represses floral transition in different types of meristems, thus regulating plant juvenility, flowering time, shoot growth pattern, and life history strategies.
The molecular mechanisms of TFL1 action remain largely unknown. So far, the question has been tackled through the analysis of its antagonism with FLOWERING LOCUS T (FT) and revealed that their balance is, at least partially, mediated by the competition for the binding to common interactors.
Abstract
Streptomyces bacteria are ubiquitous in soil, conferring the characteristic earthy smell, and they have an important ecological role in the turnover of organic material. More recently, a new ...picture has begun to emerge in which streptomycetes are not in all cases simply free-living soil bacteria but have also evolved to live in symbiosis with plants, fungi and animals. Furthermore, much of the chemical diversity of secondary metabolites produced by Streptomyces species has most likely evolved as a direct result of their interactions with other organisms. Here we review what is currently known about the role of streptomycetes as symbionts with fungi, plants and animals. These interactions can be parasitic, as is the case for scab-causing streptomycetes, which infect plants, and the Streptomyces species Streptomyces somaliensis and Streptomyces sudanensis that infect humans. However, in most cases they are beneficial and growth promoting, as is the case with many insects, plants and marine animals that use streptomycete-produced antibiotics to protect themselves against infection. This is an exciting and newly emerging field of research that will become increasingly important as the search for new antibiotics switches to unusual and under-explored environments.
Streptomyces bacteria are not simply free-living soil bacteria but have also evolved to live in symbiosis with plants, fungi and animals.
Bacillus subtilis Kovács, Ákos T.
Trends in microbiology (Regular ed.),
August 2019, 2019-08-00, 20190801, Volume:
27, Issue:
8
Journal Article
Peer reviewed
Bacillus subtilis became the most studied species in the genus Bacillus due to its natural competence for uptake of extracellular DNA that facilitates simple genetic modification and occurrence of ...sporulation, one of the first studied bacterial cell differentiation processes. The dormant spores can survive harsh circumstances (high temperature, desiccation, UV, and γ-radiation), predation by microorganisms and macroorganisms, or even extraterrestrial conditions. B. subtilis can be isolated from various environments, from soil to marine habitats, and utilized in various applications from enzyme production and food fermentation to plant biocontrol. B. subtilis is a model microorganism for studying cell division, protein secretion, surface motility (swimming, swarming, and sliding), biofilm development, attachment to plant root or fungal hyphae, secondary metabolite production, cytoplasm exchange via intercellular nanotubes, extracellular vesicle release, and kin-discrimination.
CropLife Europe collected literature values from monitoring studies measuring air concentrations of Plant Protection Products (PPPs) that may be inhaled by humans located in rural areas but not ...immediately adjacent to PPP applications. The resulting “Combined Air Concentration Database” (CACD) was used to determine whether air concentrations of PPPs reported by the French “Agency for Food, Environmental and Occupational Health & Safety” (ANSES) are consistent with those measured by others to increase confidence in values of exposure to humans. The results were put into risk assessment context. Results show that 25–90% of samples do not contain measurable PPP concentrations. Measured respirable fractions were below EU default air concentrations used for risk assessment for resident exposure by the European Food Safety Authority. All measured exposures in the CACD were also below established toxicological endpoints, even when considering the highest maximum average reported concentrations and very conservative inhalation rates. The highest recorded air concentration was for prosulfocarb (0.696 μg/m³ measured over 48 h) which is below the EFSA default limit of 1 μg/m³ for low volatility substances. In conclusion, based on the CACD, measured air concentrations of PPPs are significantly lower than EFSA default limits and relevant toxicological reference values.
•PPP air monitoring concentrations collected in Combined Air Concentration Database.•Literature values were compared with those reported by ANSES.•25–90% of samples did not contain measurable PPP concentrations.•Where quantifiable, samples were below EFSA default air vapour concentrations.•All measured concentrations were also below established toxicological endpoints.
Specific scope
This Standard provides general guidance on the need for data on possible effects of plant protection products on processes for the transformation of harvested crops and on the use of ...preliminary data to avoid the need for subsequent testing. It does not provide specific tests.
Specific approval and amendment
First approved in 2005–09.
Revision to update references approved in 2014–09.
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