The effect of abiotic stresses on plant C:N:P homeostasis and their mitigation by silicon

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

Abiotic stress on seed germination and plant growth of Zeyheria tuberculosa

Zeyheria tuberculosa(Vell.)Bureau ex Verl.is among the Brazilian flora threatened with extinction.It has high-quality wood and can be used to recover herbicidecontaminated areas.However,abiotic stresses can harm seed germination and seedling development under adverse conditions and need to be understood to improve autochthonous or indigenous biodiversity conservation and strengthen reforestation projects.This study evaluated the effects of temperature,water and saline stress on Z.tuberculosa seed germination and water stress on seedling growth.Three laboratory experiments evaluated germination under:(1)different temperatures(20,25,30,35 and 40℃);(2)different water potentials simulated with polyethylene glycol(PEG6000)at 25 and 30℃;and,(3)different osmotic potentials simulated with NaCl at 25 and 30℃.In addition,a greenhouse experiment subjected seedlings to five water regimes(20%,35%,50%,65%and 80%of maximum substrate water holding capacity).In the laboratory,seedling biometry and germination were evaluated,while physiological and morphological parameters were assessed in the greenhouse.Physiological potential of seeds increased at 25 and 30℃.Germination and vigor decreased as water and saline stresses increased.Germination tolerance thresholds for water and salt stresses were-0.6 and-0.4 MPa,respectively.In the greenhouse,the most restrictive water regimes reduced seedling physiological and morphological parameters.Seedling development was compromised at moisture levels below50%field capacity.

How Much Do Adjuvant and Nozzles Models Reduce the Spraying Drift? Drift in Agricultural Spraying

The spraying of herbicides in crops has become the main form of weed control. Although it means unexpected effects on non-target plants resulted by spraying drift. Thus, improvements in application techniques, as the best selection of spray nozzles and adjuvant, are essential to avoid environmental contamination and economic losses. On this work, we evaluate how much adjuvant associated with nozzles can reduce the spray drift. The nozzles used at experiment were air induction flat tip, hollow cone and twinjet and the spray liquids, which were composed of herbicide glyphosate and phosphatidylcholine + propionic acid adjuvant. Measurements were made at wind tunnel and droplet sizer, at laser diffraction method. The models of nozzles influence in droplet size characteristics and in occurrence of spray drift. The use of adjuvants reduces the spray drift only combined with the twinjet nozzle, while for the other models the adjuvant did not reduce the global spray drift at significant levels. The adjuvant reduced the spray drift until 39%, while the nozzles model reduced until 74%. Both techniques when combined were able to reduce until 80%. The model of nozzle has the biggest result on drift mitigation and the use of adjuvants can increase the drift mitigation specially with nozzles that produces smallest droplets.

Effect of the Growth Promoter VIUSID Agro on the Morphophysiological and Productive Performance of Tobacco Growth(Nicotiana tabacum L.)

With the objective of evaluating the effect of VIUSID agro on the morphophysiological and productive performance of tobacco seedlings,a randomised block experiment was designed with five treatments and three replications.The variants were:dosage of 0.2,0.5,0.7 and 1.0 L/ha and one control.The variables are recorded at three points of the cultivation cycle 10th,20th and 30th days after planting(DAP).Among the indicators evaluated were the fresh and dry mass of the plants,the leaves per plant,foliar area,the length and diameter of the stalk as well as the characteristics of the root.The rates of physiological growth and agricultural yield were also evaluated.The results showed a significant increase(p≤0.05)in the fresh and dry mass of the plants when VIUSID was used.Regarding the length of the stalk,the average increases of those treated in comparison to the control in the final evaluation were 28.42%,30.51%,41.17%and 38.43%.In terms of the diameter of the stalk and the foliar area in all evaluations,the treatments with VIUSID significantly exceeded the control.The absolute growth rate and net assimilation was significantly higher when the product was used.In the relative growth rate,the most favourable behaviour was the dosage of 0.5 L/ha,in final evaluation.With regard to yield,the best performance with significant differences(p≤0.05)to the other treatments was the dosage of 0.5,0.7 and 1.0 L/ha.Therefore,VIUSID agro had a positive influence on the morphophysiological and productive indicators of the tobacco seedlings.

Characterization of the Allelopathic Potential of Sugarcane Leaves and Roots

Sugarcane cultivars that are currently planted are the result of genetic improvement focused on increased crop yield. However, this selection and genetic alteration reduced the competitive potential of sugarcane, as well as its allelopathic capabilities. Many members of the Poaceae family are highly allelopathic. Thus, the objective of this study was to characterize the allelopathic potential of two sugarcane cultivars (CTC 2 and IAC 91109) by bioassay-guided fractionation, isolation, and identification of significant phytotoxins, including those that are lipophilic. For both leaves and roots, alpha-linolenic and linoleic acid were found to be the most phytotoxic compounds found with this approach. Both compounds were phytotoxic when applied in soil and caused light-independent cellular leakage of treated cucumber cotyledon discs. We conclude that some of the phytotoxic effects of sugarcane residues in soil are due to the combined action of alpha-linolenic and linoleic acid.

Productive Response of Brassica rapa L.subsp.chinensis to Application of VIUSID Agro

In order to evaluate the effect of VIUSID agro on the yield response of a pak choi harvest,a randomised block experiment was designed with four treatments and three replications.The treatments were dosages of 0.1,0.2 and 0.3 L/ha and one control.The number of leaves per plant and the fresh and dry mass of the plant were measured.In addition,growth indexes were evaluated,such as relative growth rate,active growth rate,harvest index and agricultural yield.The number of leaves per plant was significantly greater at 35 days after sowing(das)for 0.2 L/ha and 0.3 L/ha treatments,with increases of 15.0%and 14.17%relative to the control.Regarding plant length and fresh mass at the final evaluation,the treatments using higher dosages produced the best results.Regarding the active growth rate,the 0.2 L/ha dosage produced the best effects,and regarding relative growth rate,the 0.2 L/ha and 0.3 L/ha dosages produced the best results relative to the control.The harvest index did not benefit from the used dosages,while a higher agricultural yield was achieved using the 0.2 L/ha and 0.3 L/ha dosages at 18.03%and 12.88%compared to the control.Therefore,VIUSID agro positively influenced the yield behaviour of pak choi.

Ecosystem services potential and soil conservation policies with emphasis on degraded pastures in Brazil

Different global agendas have discussed the role of soils in mitigating and reducing global problems related to climate change,food security,biodiversity and erosion,among others.With this in mind,the aim was to draw up an overview of the main soil agendas in Europe and Brazil,analysing their impact on the establishment of legal frameworks for soil use and conservation.In Brazil,pastures are seen as an important alternative for converting degraded areas into ecosystem services.To this end,a literature review was carried out using databases on the Scopus,Web of Science,Science Direct and Scielo platforms,as well as consulting documents from the European Union Missions in Horizon Europe and Brazilian legislation on the subject.In a pilot river basin,the Potential for Conservation Use(PCU)method was applied,which is used in Brazil to assess the impacts of different uses on the natural capital of soils,serving as a metric to guide public soil conservation policies.It was concluded that,on the European scene,discussions on soils have taken place in an integrated and organised way,with actions to mobilise different players in society.In Brazil,even though there are important legal frameworks,actions are still restricted and disjointed,pointing to the need for progress in soil governance.In both scenarios,there is a need for scientifically validated metrics at regional scales that can contribute to a harmonised database capable of subsidising the development of efficient public policies to advance soil conservation at a global level.

Animal modeling in bone research—Should we follow the White Rabbit?

Animal models are live subjects applied to translational research.They provide insights into human diseases and enhance biomedical knowledge.Livestock development has favored the pace of human social development over millennia.Today's society is more aware of animal welfare than past generations.The general public has marked objections to animal research and many species are falling into disuse.The search for an ideal methodology to replace animal use is on,but animal modeling still holds great importance to human health.Bone research,in particular,has unmet requirements that in vitro technologies cannot fully address.Standardizing novel models remains necessary and rabbits are gaining in popularity as potential bone models.Our aim here is to provide a broad overview of animal modeling and its ethical implications,followed by a narrower focus on bone research and the role rabbits are playing in the current scenario.

Immunosuppressive,antimicrobial and insecticidal activities of inhibitor cystine knot peptides produced by teratocytes of the endoparasitoid wasp Cotesia flavipes(Hymenoptera:Braconidae)

Teratocytes are specialized cells released by parasitoid wasps into their hosts.They are known for producing regulatory molecules that aid the development of imma-ture parasitoids.We have recently reported the primary structures of cystine-rich peptides,including some containing inhibitor cystine knot(ICK)motifs,produced by teratocytes of the parasitoid Cotesia flavipes(Hymenoptera:Braconidae).ICKs are known for their stability and diverse biological functions.In this study,we produced four putative ICK peptides from the teratocytes of C.Jlavipes using solid-phase peptide synthesis or recom-binant expression in E.coli,and investigated their functions on host immune modulation as well their potential to impair the development of two lepidopterans after ingestion of the peptides.In addition,the peptides were assayed against pathogens and human cells.The peptides did not influence total hemocyte count but suppressed cellular immunity,detectable as a reduction of hemocyte encapsulation(CtICK-I,CftICK-II,CtICK-I)and spread indexes(CftICK-IV)in the host.None of the peptides influenced the activi-ties of prophenoloxidase and phenoloxidase in the hemolymph of larval Diatraea sacchar-alis(Lepidoptera:Crambidae).CftICK-I and CftICK-II with previously unknown function showed antifungal activity against Candida albicans but were non-toxic to human cells.CtICK-I,CftICK-II,and CftICK-II increased larval mortality and reduced leaf consump-tion of D.saccharalis,a permissive host for C.flavipes.The CftICK-III also increased larval mortality and reduced leaf consumption of Spodoptera frugiperda(Lepidoptera:Noctuidae),a non-permissive host for C.flavipes.This study highlights biological func-tions and biotechnological potential of ICK peptides from the teratocytes of C.flavipes.

Antimicrobial peptides as a feed additive alternative to animal production, food safety and public health implications: An overview

In the last few years,feed additives have been used in animal nutrition to improve nutrient utilization,health parameters and animal performance.However,the use of antibiotics as feed additives has allowed the occurrence of antimicrobial resistance(AMR),which can bring as a consequence,an increase in the morbidity and mortality of diseases that were previously treatable with antibiotics.In this context,antimicrobial peptides(AMP)have appeared as a promising strategy because they have multiple bio-logical activities and represent a powerful strategy to prevent the development of resistant microor-ganisms.Despite the small number of studies applied in vivo,AMP appear as a potent alternative to the use of antibiotics in animal nutrition,due to an increase in feed efficiency and the prevention/treatment of some animal diseases.This review discusses the problems associated with antimicrobial resistance and the use of AMP as a strong candidate to replace conventional antibiotics,mainly in the animal industry.