Application of nanoparticles entrapped orange essential oil to inhibit the incidence of phytopathogenic fungi during storage of agroecological maize seeds

The demand for sustainable, healthy, and pesticide-free food has grown in recent years. Agroecological seeds cannot receive chemical treatment, as pesticides present toxicological and environmental risks, requiring the development of alternative methods for disease control, such as the use of essential oils. In this study, orange essential oil was extracted and encapsulated in zein nanoparticles by the nanoprecipitation method. The nanoparticles were tested for the antifungal activity on agroecological maize seeds and for the mycelial sensitivity of Stenocarpella macrospora. The synthesized nanoparticles presented good encapsulation efficiency (99 %) of orange essential oil rich in D-limonene, conferring high antioxidant activity to the loaded nanoparticles. The release profile indicated a pseudo-Fickian mechanism governed by diffusion, explained according to the Korsmeyer-Peppas model. The dynamic light scattering, and transmission electron microscopy showed spherical nanoparticles with particle size lower than 200 nm. The nanoparticles containing orange essential oil inhibited the incidence of Fusarium during the storage of agroecological maize seeds. The mycelial sensitivity against Stenocarpella macrospora showed that the encapsulated essential oil was more effective in inhibiting the fungus when compared to the non-encapsulated oil. Therefore, the nanoparticles containing encapsulated orange essential oil can be effectively applied as an antifungal material for the conservation of agroecological maize seeds, contributing to the development of sustainable agricultural biotechnology with pesticide-free products.

Advanced biotechnological strategies towards the development of crops with enhanced micronutrient content

Micronutrients are essential mineral elements required for both plant and human development.An integrated system involving soil, climatic conditions, and types of crop plants determines the level of micronutrient acquisition and utilization. Most of the staple food crops consumed globally predominantly include the cereal grains, tubers and roots, respectively and in many cases, particularly in the resource-poor countries they are grown in nutrient-deficient soils. These situations frequently lead to micronutrient deficiency in crops. Moreover, crop plants with micronutrient deficiency also show high level of susceptibility to various abiotic and biotic stress factors. Apart from this, climate change and soil pollution severely affect the accumulation of micronutrients, such as zinc (Zn), iron (Fe), selenium (Se), manganese (Mn), and copper (Cu) in food crops. Therefore, overcoming the issue of micronutrient deficiency in staple crops and to achieve the adequate level of food production with enriched nutrient value is one of the major global challenges at present. Conventional breeding approaches are not adequate to feed the increasing global population with nutrient-rich staple food crops. To address these issues, alongside traditional approaches, genetic modification strategies have been adopted during the past couple of years in order to enhance the transport, production, enrichment and bioavailability of micronutrients in staple crops. Recent advances in agricultural biotechnology and genome editing approaches have shown promising response in the development of micronutrient enriched biofortified crops. This review highlights the current advancement of our knowledge on the possible implications of various biotechnological tools for the enrichment and enhancement of bioavailability of micronutrients in crops.

Lessons learned from the introduction of genetically engineered crops: relevance to gene drive deployment in Africa

The application of gene drives to achieve public health goals, such as the suppression of Anopheles gambiae populations, or altering their ability to sustain Plasmodium spp. infections, has received much attention from researchers. If successful, this genetic tool can contribute greatly to the wellbeing of people in regions severely affected by malaria. However, engineered gene drives are a product of genetic engineering, and the experience to date, gained through the deployment of genetically engineered (GE) crops, is that GE technology has had difficulty receiving public acceptance in Africa, a key region for the deployment of gene drives. The history of GE crop deployment in this region provides good lessons for the deployment of gene drives as well. GE crops have been in commercial production for 24 years, since the planting of the first GE soybean crop in 1996. During this time, regulatory approvals and farmer adoption of these crops has grown rapidly in the Americas, and to a lesser extent in Asia. Their safety has been recognized by numerous scientific organizations. Economic and health benefits have been well documented in the countries that have grown them. However, only one transgenic crop event is being grown in Europe, and only in two countries in that region. Europe has been extremely opposed to GE crops, due in large part to the public view of agriculture that opposes “industrial” farming. This attitude is reflected in a highly precautionary regulatory and policy environment, which has highly influenced how African countries have dealt with GE technology and are likely to be applied to future genetic technologies, including gene drives. Furthermore, a mistrust of government regulatory agencies, the publication of scientific reports claiming adverse effects of GE crops, the involvement of corporations as the first GE crop developers, the lack of identifiable consumer benefit, and low public understanding of the technology further contributed to the lack of acceptance. Coupled with more emotionally impactful messaging to the public by opposition groups and the general tendency of negative messages to be more credible than positive ones, GE crops failed to gain a place in European agriculture, thus influencing African acceptance and government policy. From this experience, the following lessons have been learned that would apply to the deployment of gene drives, in Africa:

It will be important to establish trust in those who are developing the technology, as well as in those who are making regulatory decisions. Engagement of the community, where those who are involved are able to make genuine contributions to the decision-making process, are necessary to achieve that trust. The use of tools to facilitate participatory modeling could be considered in order to enhance current community engagement efforts.

Trusted, accurate information on gene drives should be made available to the general public, journalists, and scientists who are not connected with the field. Those sources of information should also be able to summarize and analyze important scientific results and emerging issues in the field in order to place those developments in the proper context. Engagement should involve more opportunities for participation of stakeholders in conceptualizing, planning, and decision-making.

Diversifying the source of funding for gene drive research and development, particularly by participation of countries and regional bodies, would show that country or regional interests are represented.

Efforts by developers and neutral groups to provide the public and decisionmakers with a more thorough understanding of the benefits and risks of this technology, especially to local communities, would help them reach more informed decisions.

A better understanding of gene drive technology can be fostered by governments, as part of established biosafety policy in several African countries. Developers and neutral groups could also be helpful in increasing public understanding of the technology of genetic engineering, including gene drives.

Effective messaging to balance the messaging of groups opposed to gene drives is needed. These messages should be not only factual but also have emotional and intuitive appeal.

Non-synonymous substitution of evolutionarily conserved residue in Tau class glutathione transferases alters structural and catalytic features

Plant-specific tau glutathione transferases (GSTs) are basically involved in catalysing γ-glutathione (GSH)-dependent conjugation reactions with pesticides and herbicides, which play an important role in the detoxification of pollutants. Given the lack of systematic biochemical and structural information on tau GSTs, the study of their mediated defence mechanisms against toxic compounds has been greatly hindered. Here, we reveal the importance of the Ile residue closely interacting with GSH for the structural stability and catalytic function of GST. Evolutionary conservation analysis indicated that the crucial G-site Ile55 in the SbGSTU6 was converted to Thr53 of SbGSTU7. The comparative biochemical data on SbGSTU6, SbGSTU7 and their mutants showed that the substitution of Ile by Thr caused significant decrease in the affinity and catalytic efficiency of the GSTs. The unfavourable structural flexibility and pKa distribution of the active cavity residues were also demonstrated. Crystallography studies and molecular dynamics simulations showed that the conversion resulted in the hydrogen bond recombination with GSH and conformational rearrangement of GST active cavity, in which the Ile residue was more conducive to the formation of enzyme substrate complexes. The extensive biochemical and structural data not only reveal the critical role of the conserved G-site Ile residue in catalysing GSH-conjugate reactions but also provide valuable resources for the development of GST engineering in analytical and agricultural biotechnology.

Regulatory approaches for genome edited agricultural plants in select countries and jurisdictions around the world

Genome editing in agriculture and food is leading to new, improved crops and other products. Depending on the regulatory approach taken in each country or region, commercialization of these crops and products may or may not require approval from the respective regulatory authorities. This paper describes the regulatory landscape governing genome edited agriculture and food products in a selection of countries and regions.

Positive effects of biocholine powder dietary supplementation on milk production and quality, and antioxidant responses in lactating ewes: A new nutritional tool

We determined whether the dietary supplementation with a commercial product (vegetable biocholine - VB) for Lacaune ewes at peak lactation would improve animal health and production as well as milk quality. We also determined the effects of VB as a feed additive. We used thirty Lacaune ewes at 30 days of lactation, allocated into three groups: T0 (control, without VB), T5 (5 g of VB/animal/day) and T10 (10 g of VB/animal/day). T10 sheep had greater milk yield during the experimental period. T10 ewes had also a significantly lower feed conversion ratio than the other groups. Total solids concentration of milk was higher in T10 than in the other groups on day 20. The somatic cell count in milk was lower in ewes that consumed VB in the highest dose (T10) than in the T0 and T5 in days 15 and 20. Lower levels of lipoperoxidation (LPO) and of reactive oxygen species (ROS) were observed in milk from ewes fed with the VB supplemented diet on day 20, associated with increased levels of total antioxidant capacity and superoxide dismutase activity in milk. In serum, we found that T5 and T10 animals had significantly higher levels of non-enzymatic antioxidants (non-protein thiols) associated with reduced LPO and ROS content. Higher levels of globulins were observed in T10 than in T0 sheep on day 20. These data suggest that VB dietary supplementation stimulates antioxidant responses and increases the concentration of globulins in a manner beneficial to sheep health. Milk production, feed conversion rate, and milk SCC were also improved.

Perspectives of photodynamic therapy in biotechnology

Photodynamic therapy (PDT) is a current and innovative technique that can be applied in different areas, such as medical, biotechnological, veterinary, among others, both for the treatment of different pathologies, as well as for diagnosis. It is based on the action of light to activate photosensitizers that will perform their activity on target tissues, presenting high sensitivity and less adverse effects. Therefore, knowing that biotechnology aims to use processes to develop products aimed at improving the quality of life of human and the environment, and optimizing therapeutic actions, researchers have been used PDT as a tool of choice. This review aims to identify the impacts and perspectives and challenges of PDT in different areas of biotechnology, such as health and agriculture and oncology. Our search demonstrated that PDT has an important impact around oncology, minimizing the adverse effects and resistance to chemotherapeutic to the current treatments available for cancer. Veterinary medicine is another area with continuous interest in this therapy, since studies have shown promising results for the treatment of different animal pathologies such as Bovine mastitis, Malassezia, cutaneous hemangiosarcoma, among others. In agriculture, PDT has been used, for example, to remove traces of antibiotics of milk. The challenges, in general, of PDT in the field of biotechnology are mainly the development of effective and non-toxic or less toxic photosensitizers for humans, animals and plants. We believe that there is a current and future potential for PDT in different fields of biotechnology due to the existing demand.

Between mice and sheep: Biotechnology, agricultural science and animal models in late-twentieth century Edinburgh

In this paper, we investigate the ways in which a group of scientists in Edinburgh worked across mice and sheep during the last quarter of the twentieth century. With this local episode, we show the utility of an interspecies perspective to investigate recent historical transformations in the life sciences. We argue that the emergence of animal biotechnology was the result of interactions between neoliberal policymakers, science administrators, molecular biologists, agricultural breeders, and the laboratory and farm organisms with which they worked. During the early 1980s, all these actors believed that the exportation of genetic engineering techniques from mice to farm animals would lead to more effective breeding programmes in the agricultural sciences. However, the circulation of people, money, expertise and infrastructures that the experiments required, as well as the practical constraints of working with mice and sheep, resisted a simple scaling-up from one organism to the other. This displaced the goals of the Edinburgh scientists from the production of transgenic sheep to stem cell research and human regenerative medicine. We account for this unexpected shift by looking at the interplay between science policy and its implementation via collective action and bench work across different organisms. The emergence of animal biotechnology in Edinburgh also provides historiographical insights on the birth of Dolly the sheep and, more generally, on the interactions between the molecular and the reproductive sciences at the fall of the twentieth century.

Benefits of genome-edited crops: expert opinion

Innovation in agriculture is pervasive. However, in spite of the success stories of twentieth century plant breeding, the twenty-first century has ushered in a set of challenges that solutions from the past century are unlikely to address. However, sustained research and the amalgamation of a number of disciplines has resulted in new breeding techniques (NBTs), such as genome editing, which offer the promise of new opportunities to resolve some of the issues. Here we present the results of an expert survey on the added potential benefits of genome-edited crops compared to those developed through genetic modification (GM) and conventional breeding. Overall, survey results reveal a consensus among experts on the enhanced agronomic performance and product quality of genome-edited crops over alternatives. The majority of experts indicated that the regulations for health and safety, followed by export markets, consumers, and the media play a major role in determining where and how NBTs, including genome editing, will be developed and used in agriculture. Further research is needed to gauge expert opinion after the Court of Justice of the European Union ruling establishing that site-specific mutagenic breeding technologies are to be regulated in the same fashion as GM crops, regardless of whether foreign DNA is present in the final variety.

Where are the drought tolerant crops? An assessment of more than two decades of plant biotechnology effort in crop improvement

Since the dawn of modern biotechnology public and private enterprise have pursued the development of a new breed of drought tolerant crop products. After more than 20 years of research and investment only a few such products have reached the market. This is due to several technical and market constraints. The technical challenges include the difficulty in defining tractable single-gene trait development strategies, the logistics of moving traits from initial to commercial genetic backgrounds, and the disconnect between conditions in farmer's fields and controlled environments. Market constraints include the significant difficulty, and associated costs, in obtaining access to markets around the world. Advances in the biology of plant water management, including response to water deficit reveal new opportunities to improve crop response to water deficit and new genome-based tools promise to usher in the next era of crop improvement. As biotechnology looks to improve crop productivity under drought conditions, the environmental and food security advantages will influence public perception and shift the debate toward benefits rather than risks.

A look into a multifunctional toolbox: endophytic Bacillus species provide broad and underexploited benefits for plants

One of the major challenges of agriculture currently is to obtain higher crop yield. Environmental conditions, cultivar quality, and plant diseases greatly affect plant productivity. On the other hand, several endophytic Bacillus species have emerged as a complementary, efficient, and safe alternative to current crop management practices. The ability of Bacillus species to form spores, which resist adverse conditions, is an advantage of the genus for use in formulations. Endophytic Bacillus species provide plants with a wide range of benefits, including protection against phytopathogenic microorganisms, insects, and nematodes, eliciting resistance, and promoting plant growth, without causing damage to the environment. Bacillus thuringiensis, B. subtilis, B. amyloliquefaciens, B. velezensis, B. cereus, B. pumilus, and B. licheniformis are the most studied Bacillus species for application in agriculture, although other species within the genus have also shown great potential. Due to the increasing number of whole-genome sequenced endophytic Bacillus spp. strains, various bioactive compounds have been predicted. These data reveal endophytic Bacillus species as an underexploited source of novel molecules of biotechnological interest. In this review, we discuss how endophytic Bacillus species are a valuable multifunctional toolbox to be integrated with crop management practices for achieving higher crop yield.

Safety of Pseudomonas chlororaphis as a gene source for genetically modified crops

Genetically modified crops undergo extensive evaluation to characterize their food, feed and environmental safety prior to commercial introduction, using a well-established, science-based assessment framework. One component of the safety assessment includes an evaluation of each introduced trait, including its source organism, for potential adverse pathogenic, toxic and allergenic effects. Several Pseudomonas species have a history of safe use in agriculture and certain species represent a source of genes with insecticidal properties. The ipd072Aa gene from P. chlororaphis encodes the IPD072Aa protein, which confers protection against certain coleopteran pests when expressed in maize plants. P. chlororaphis is ubiquitous in the environment, lacks known toxic or allergenic properties, and has a history of safe use in agriculture and in food and feed crops. This information supports, in part, the safety assessment of potential traits, such as IPD072Aa, that are derived from this source organism.

The role of community engagement in the adoption of new agricultural biotechnologies by farmers: the case of the Africa harvest tissue-culture banana in Kenya

Background

The tissue culture banana (TCB) is a biotechnological agricultural innovation that has been adopted widely in commercial banana production. In 2003, Africa Harvest Biotech Foundation International (AH) initiated a TCB program that was explicitly developed for smallholder farmers in Kenya to help them adopt the TCB as a scalable agricultural business opportunity. At the heart of the challenge of encouraging more widespread adoption of the TCB is the question: what is the best way to introduce the TCB technology, and all its attendant practices and opportunities, to smallholder farmers. In essence, a challenge of community or stakeholder engagement (CE).

Results

In this paper, we report the results of a case study of the CE strategies employed by AH to introduce TCB agricultural practices to small-hold farmers in Kenya, and their impact on the uptake of the TCB, and on the nature of the relationship between AH and the relevant community of farmers and other stakeholders. We identified six specific features of CE in the AH TCB project that were critical to its effectiveness: (1) adopting an empirical, “evidence-based” approach; (2) building on existing social networks; (3) facilitating farmer-to-farmer engagement; (4) focusing engagement on farmer groups; (5) strengthening relationships of trust through collaborative experiential learning; and (6) helping farmers to “learn the marketing game”. We discuss the implications of AH’s “values-based” approach to engagement, and how these guiding values functioned as “design constraints” for the key features of their CE strategy. And we highlight the importance of attention to the human dimensions of complex partnerships as a key determinant of successful CE.

Conclusion

Our findings suggest new ways of conceptualizing the relationship between CE and the design and delivery of new technologies for global health and global development.

How to be Cautious but Open to Learning: Time to Update Biotechnology and GMO Legislation

Precautionary measures to protect human health and the environment should be science based. This implies that they should be directed at a potential danger for which there is credible scientific evidence (although that evidence need not be conclusive). Furthermore, protective measures should be updated as relevant science advances. This means that decisionmakers should be prepared to strengthen the precautionary measures if the danger turns out to be greater than initially suspected, and to reduce or lift them, should the danger prove to be smaller. Most current legislation on agricultural biotechnology has not been scientifically updated. Therefore, it reflects outdated criteria for identifying products that can cause problems. Modern knowledge in genetics, plant biology, and ecology has provided us with much better criteria that risk analysts can use to identify the potentially problematic breeding projects at which precautionary measures should be directed. Legislation on agricultural biotechnology should be scientifically updated. Furthermore, legislators should learn from this example that regulations based on the current state of science need to have inbuilt mechanisms for revisions and adjustments in response to future developments in science.

Optimization of single plate-serial dilution spotting (SP-SDS) with sample anchoring as an assured method for bacterial and yeast cfu enumeration and single colony isolation from diverse samples

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SP-SDS forms a simple tool for bacterial cfu estimation for samples with unknown cfu.

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Prime recommendation of anchoring specimens to fixed initial OD or a standard base.

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Six serial dilutions of 20 μl each applied per 9-cm plate followed by manual counting.

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Suits pure and mixed bacterial stocks, spores, yeasts and composite samples.

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Superior to alternate techniques like track-dilution, drop-plating or drop-spotting.

We propose a simple technique for bacterial and yeast cfu estimations from diverse samples with no prior idea of viable counts, designated as single plate-serial dilution spotting (SP-SDS) with the prime recommendation of sample anchoring (10⁰ stocks). For pure cultures, serial dilutions were prepared from 0.1 OD (10⁰) stock and 20 μl aliquots of six dilutions (10¹–10⁶) were applied as 10–15 micro-drops in six sectors over agar-gelled medium in 9-cm plates. For liquid samples 10⁰–10⁵ dilutions, and for colloidal suspensions and solid samples (10% w/v), 10¹–10⁶ dilutions were used. Following incubation, at least one dilution level yielded 6–60 cfu per sector comparable to the standard method involving 100 μl samples. Tested on diverse bacteria, composite samples and Saccharomyces cerevisiae, SP-SDS offered wider applicability over alternative methods like drop-plating and track-dilution for cfu estimation, single colony isolation and culture purity testing, particularly suiting low resource settings.

Amelioration of high salinity stress damage by plant growth-promoting bacterial endophytes that contain ACC deaminase

Plant growth and productivity is negatively affected by soil salinity. However, it is predicted that plant growth-promoting bacterial (PGPB) endophytes that contain 1-aminocyclopropane-1-carboxylate (ACC) deaminase (E.C. 4.1.99.4) can facilitate plant growth and development in the presence of a number of different stresses. In present study, the ability of ACC deaminase containing PGPB endophytes Pseudomonas fluorescens YsS6, Pseudomonas migulae 8R6, and their ACC deaminase deficient mutants to promote tomato plant growth in the absence of salt and under two different levels of salt stress (165 mM and 185 mM) was assessed. It was evidence that wild-type bacterial endophytes (P. fluorescens YsS6 and P. migulae 8R6) promoted tomato plant growth significantly even in the absence of stress (salinity). Plants pretreated with wild-type ACC deaminase containing endophytic strains were healthier and grew to a much larger size under high salinity stress compared to plants pretreated with the ACC deaminase deficient mutants or no bacterial treatment (control). The plants pretreated with ACC deaminase containing bacterial endophytes exhibit higher fresh and dry biomass, higher chlorophyll contents, and a greater number of flowers and buds than the other treatments. Since the only difference between wild-type and mutant bacterial endophytes was ACC deaminase activity, it is concluded that this enzyme is directly responsible for the different behavior of tomato plants in response to salt stress. The use of PGPB endophytes with ACC deaminase activity has the potential to facilitate plant growth on land that is not normally suitable for the majority of crops due to their high salt contents.

Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization

BACKGROUND

Although the system for producing yellow corn grain is well established in the US, its role among other biofeedstock alternatives to petroleum-based energy sources has to be balanced with its predominant purpose for food and feed as well as economics, land use, and environmental stewardship. We model land usage attributed to corn ethanol production in the US to evaluate the effects of anticipated technological change in corn grain production, ethanol processing, and livestock feeding through a multi-disciplinary approach. Seven scenarios are evaluated: four considering the impact of technological advances on corn grain production, two focused on improved efficiencies in ethanol processing, and one reflecting greater use of ethanol co-products (that is, distillers dried grains with solubles) in diets for dairy cattle, pigs, and poultry. For each scenario, land area attributed to corn ethanol production is estimated for three time horizons: 2011 (current), the time period at which the 15 billion gallon cap for corn ethanol as per the Renewable Fuel Standard is achieved, and 2026 (15 years out).

RESULTS

Although 40.5% of corn grain was channeled to ethanol processing in 2011, only 25% of US corn acreage was attributable to ethanol when accounting for feed co-product utilization. By 2026, land area attributed to corn ethanol production is reduced to 11% to 19% depending on the corn grain yield level associated with the four corn production scenarios, considering oil replacement associated with the soybean meal substituted in livestock diets with distillers dried grains with solubles. Efficiencies in ethanol processing, although producing more ethanol per bushel of processed corn, result in less co-products and therefore less offset of corn acreage. Shifting the use of distillers dried grains with solubles in feed to dairy cattle, pigs, and poultry substantially reduces land area attributed to corn ethanol production. However, because distillers dried grains with solubles substitutes at a higher rate for soybean meal, oil replacement requirements intensify and positively feedback to elevate estimates of land usage.

CONCLUSIONS

Accounting for anticipated technological changes in the corn ethanol system is important for understanding the associated land base ascribed, and may aid in calibrating parameters for land use models in biofuel life-cycle analyses.