Hongos endófitos: ventajas adaptativas que habitan en el interior de las plantas

Endophytic fungi often develop a systemic and mutually beneficial association with their hosts. A wide range of economically important plants have been reported to harbor endophytes. In these symbiotic mutualisms, both host and symbiont gain benefits from the association. The fungus obtains nutrients form its host and in return it provides protection from abiotic (environmental stresses) and biotic stresses (pest and insect attacks) to its host plant. Endophytes have been shown to confer enhanced fitness to their hosts such as enhanced tillering, drought tolerance, root growth, overall enhanced plant growth. This work describes the detection, isolation and genetic transformation of an endophytic fungus, Acremonium implicatum, from Brachiaria brizantha accession CIAT 6780. The results open possibilities for exploiting the qualities of an introduced gene as a reporter and study the interactions between A. implicatum and its host Brachiaria. Furthermore, it also provides options to use a transformed A. implicatum as a vehicle for production and delivery of gene products of agronomic interest into the host plant in order to enhance protective benefits and other traits of agronomic importance that will contribute to improved plant productivity. Key words: genetic transformation, gene reporter, green fluorescent protein (GFP), plant-endophyte interaction. Los hongos endófitos son organismos inherentes a las plantas que establecen una asociación específica con su hospedero para mutuo beneficio. Existen sinnúmero de especies vegetales de importancia económica que interactúan con especies de hongos endófitos. La planta provee al hongo alimento, hospedaje y protección; por su parte, aunque no hay certeza sobre los mecanismos de acción, los endófitos confieren gran potencial adaptativo a las especies vegetales hospederas frente a condiciones adversas que generen estrés, ya sean de tipo abiótico (salinidad, acidez) o biótico (ataque de plagas). Esta simbiosis otorga mayor habilidad competitiva a las plantas y permite una plena expresión de su potencial genético traducido en altas tasas de germinación, mejor densidad, más biomasa en los tejidos y mayor producción de semilla. Se reporta la detección, aislamiento y transformación del hongo filamentoso endófito Acremonium implicatum aislado de la accesión Ciat 6780 del pasto Brachiaria brizantha en el laboratorio del Programa de Patología de Forrajes del Ciat. El trabajo abre amplias posibilidades para el estudio de la interacción planta-endófito y permite explorar su potencial como un sistema alternativo de expresión de genes que confieran resistencia a plagas y enfermedades sin recurrir al uso de plantas transgénicas. En los hospederos, los endófitos transgénicos pueden ser usados como vehículo para la producción y entrega de productos generados a partir de genes de interés agronómico, cumpliendo funciones protectoras y proporcionando otras ventajas que se vean reflejadas en una mayor productividad de la planta. 

Overview of antimicrobial compounds from African edible insects and their associated microbiota

This review discusses advances in the identification and bioactivity analysis of insect antimicrobial peptides (AMP) compounds, with a focus on small molecules associated with the microbiota of selected African edible insects. These molecules could be used as templates for developing next-generation drugs to combat multidrug-resistant pathogens. Previous research indicates that each insect species produces a distinct antimicrobial peptide that acts against specific microorganisms. The article analyzes several likely AMP-producing insects and their compounds. Edible insect-produced AMPs/small molecules’ chemistry receives little attention as researchers have concentrated on the discovery of antibacterial and antifungal peptides/polypeptides in plants

Climate-Smart \u3cem\u3eBrachiaria\u3c/em\u3e Grasses for Improving Livestock Production in East Africa

Climate change is a global phenomenon with negative impacts severely felt by poor people in developing countries (Morton 2007). Across many parts of Africa, rural poor communities rely greatly for their survival on agriculture and livestock that are amongst the most climate-sensitive economic sectors. Climate-smart agriculture helps farmers to increase food production, become more resilient to climate change and reduce greenhouse gas (GHG) emissions. The main anthro-pogenic GHGs are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O); they are critically important for regulating the Earth’s surface temperature. Inadequate quantity and quality of feed is a major constraint to livestock production, particularly during the dry seasons across Africa. The overall objective of this inter-institutional program is to increase feed availability in action areas of the target countries in East Africa (e.g. Kenya, Rwanda) by use of climate-smart Brachiaria forage grasses (Rao et al. 2011) for increased animal productivity and for generation of extra income to smallholder famers. An innovative programmatic approach will be used to reintroduce high quality, persistent and productive Brachiaria genotypes that were selected and improved in Latin America (Miles et al. 2004) back to Africa. These forage grasses will contribute to alleviate feed shortages, increase income to resource poor farmers, improve soil fertility, adapt to and mitigate climate change, increase milk and beef production, and as a result improve livelihoods and protect the environment

Harmonizing the agricultural biotechnology debate for the benefit of African farmers

The intense debate over agricultural biotechnology is at once fascinating, confusing and disappointing. It is complicated by issues of ethical, moral, socio-economic, political, philosophical and scientific import. Its vocal champions exaggerate their claims of biotechnology as saviour of the poor and hungry, while, equally loudly, its opponents declare it as the doomsday devil of agriculture. Sandwiched between these two camps is the rest of the public, either absorbed or indifferent. Biotechnology issues specific to the African public must include crop and animal productivity, food security, alleviation of poverty and gender equity, and must exclude political considerations. Food and its availability are basic human rights issues—for people without food, everything else is insignificant. Although we should discuss and challenge new technologies and their products, bringing the agricultural biotechnology debate into food aid for Africa where millions are faced with life-or-death situations is irresponsible. Agricultural biotechnology promises the impoverished African a means to improve food security and reduce pressures on the environment, provided the perceived risks associated with the technology are addressed. This paper attempts to harmonize the debate, and to examine the potential benefits and risks that agricultural biotechnology brings to African farmers. Key words: Agriculture, biotechnology, biotechnology debate, biotechnology and Africa, biotechnology issues, food security, poverty alleviation. African Journal of Biotechnology Vol.2(11) 2003: 394-41

Companion crops alter olfactory responses of the fall armyworm (Spodoptera frugiperda) and its larval endoparasitoid (Cotesia icipe)

AVAILABILITY OF DATA AND MATERIALS : The data sets generated during the current study are available from the corresponding author upon reasonable request.ADDITIONAL FILE 1: TABLE S1. Plant combinations used to test the preference of FAW in dual and multiple-choice oviposition assays. FIGURE S1. Representative GC–MS profiles of companion plants. Identities of the peaks are shown in Tables 2 and 7 and depict the predominant compounds based on analysis of similarities.BACKGROUND : The fall armyworm (FAW), Spodoptera frugiperda, is a devastating invasive pest and a threat to food security in Africa, with yield losses of 20–50%. Recent studies highlighted the importance of cereal crops such as maize and sorghum as the most preferred host plants for FAW oviposition. In the current work, we investigated the olfactory responses of FAW and its key larval endoparasitoid Cotesia icipe to odours from the preferred host (maize) in the presence of six potential companion crops including beans, groundnut, sweet potato, greenleaf- and silverleaf desmodium, and cassava. We hypothesized that odours released by companion crops in maize-based intercropping systems would alter host preferences of FAW for oviposition and its parasitoid responses. RESULTS : In dual choice oviposition bioassays, FAW laid significantly more eggs on maize than on the other plants. However, in the multiple-choice bioassays, significantly fewer eggs were laid on maize when companion plants were present except cassava. While wind tunnel bioassays confirmed the differential behavioural responses of FAW, we found that its larval endoparasitoid C. icipe was attracted to volatiles from the companion plants tested individually and/or when they were combined with maize. Coupled gas chromatography–mass spectrometry (GC–MS) analysis detected several potential behaviour-modifying compounds including (Z)-3-hexenyl acetate, (E)-β-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-β-caryophyllene, camphor, methyl salicylate and (E, E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. CONCLUSIONS : Our findings provide evidence supporting diversified maize cropping system could reduce FAW damage by repelling the pest while simultaneously recruiting its natural enemies. Hence, diversifying cereal cropping system with companion crops could serve as an ecologically sustainable FAW management strategy.The European Union (EU); icipe core funding provided by the Swedish International Development Cooperation Agency (Sida); the Swiss Agency for Development and Cooperation (SDC); the Australian Centre for International Agricultural Research (ACIAR), the Federal Democratic Republic of Ethiopia, and the Government of the Republic of Kenya; the Deutscher Akademischer Austauschdienst (DAAD) In-Region Postgraduate Scholarship.https://chembioagro.springeropen.comam2024Zoology and EntomologySDG-02:Zero Hunge

Unlocking the potential of substrate quality for the enhanced antibacterial activity of black soldier fly against pathogens

SUPPORTING INFORMATION : Pearson’s correlation coefficient (r) for proximate analysis and antibacterial activity of hexane extract (Figure S1); concentrations of methylated fatty acid from GC-MS (Table S1); mass of HIL in different growth stages (Table S2); antibacterial activity of HIL extracted with hexane (Table S3); antibacterial activity of HIL extracted with 20% acetic acid (Table S4); and antibacterial activity of HIL extracted with 80% methanol (Table S5).Globally, antibiotics are facing fierce resistance from multidrug-resistant bacterial strains. There is an urgent need for eco-friendly alternatives. Though insects are important targets for antimicrobial peptides, it has received limited research attention. This study investigated the impact of waste substrates on the production of antibacterial agents in black soldier fly (Hermetia illucens L.) larvae (HIL) and their implications in the suppression of pathogens [Bacillus subtilis (ATCC 6051), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922)]. The 20% acetic acid (AcOH) extract from market waste had the highest antibacterial activity with an inhibition zone of 17.00 mm, followed by potato waste (15.02 mm) against S. aureus. Hexane extract from HIL raised on market waste also showed a significant inhibitory zone (13.06 mm) against B. subtilis. Minimum inhibitory concentration (MIC) values recorded were 25 mg/mL against all test pathogens. The fastest time-kill of 20% AcOH extract was 4 h against B. subtilis, E. coli, andP. aeruginosa. Lauric acid was also identified as the dominant component of the various hexane extracts with concentrations of 602.76 and 318.17 μg/g in HIL reared on potato and market waste, respectively. Energy from the market waste substrate correlated significantly (r = 0.97) with antibacterial activities. This study highlights the key role of substrate quality and extraction methods for enhancing the production of antibacterial agents in HIL, thus providing new insights into the development of potential drugs to overcome the alarming concerns of antimicrobial resistance.Australian Centre for International Agricultural Research, Norwegian Agency for Development Cooperation, Norad, Novo Nordisk Foundation, the Rockefeller Foundation, Bill & Melinda Gates Foundation, Horizon Europe, the Curt Bergfors Foundation Food Planet Prize Award, Norwegian Agency for Development Cooperation, the Section for Research, Innovation, and Higher Education, Egerton University and icipe core funding provided by the Swedish International Development Cooperation Agency (Sida); the Swiss Agency for Development and Cooperation (SDC); the Australian Centre for International Agricultural Research (ACIAR); the Norwegian Agency for Development Cooperation (Norad); the Federal Democratic Republic of Ethiopia; and the Government of the Republic of Kenya.https://pubs.acs.org/journal/acsodfhj2024ChemistrySDG-03:Good heatlh and well-bein

Evolving dynamics of insect frass fertilizer for sustainable nematode management and potato production

Potato production faces major challenges from inadequate soil fertility, and nematode infestation, yet synthetic fertilizers and nematicides are costly and harmful to the environment. This study explored the potential of chitin-fortified black soldier fly-composted organic fertilizer (BSFCOF) as a multipurpose organic fertilizer amendment for enhancing potato yield and suppressing potato cyst nematodes (PCN). The BSFCOF was applied at a rate equivalent to 150 kg N ha-1 and fortified with chitin from black soldier fly pupal exuviae at inclusion rates equivalent to 0.5, 1, 2, 3, 4 and 5% chitin. Data were collected on potato growth characteristics, PCN population densities, and soil chemical properties for two growing cycles. Results showed that chitin fortified BSFCOF significantly improved potato growth parameters, chlorophyll concentration, marketable tuber yield and number of marketable tubers. The marketable tuber yield achieved using chitin-fortified BSFCOF was 70 – 362%, and 69 – 238% higher than the values achieved using unfertilized soil during the first and second growing cycles, respectively. Soil amendment with chitin-fortified BSFCOF significantly reduced the number of cysts per 200 g soil-1, number of eggs and J2 per cyst-1, eggs g-1 soil and reproduction rate by 32 – 87%, 9 – 92%, 31– 98% and 31 – 98%, respectively. The PCN suppression increased with chitin inclusion rates. There were significantly higher values for soil pH, ammonium nitrogen, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity in soil amended with BSFCOF compared to unamended soil. This study demonstrates that BSFCOF fortified with 5% chitin is an effective soil enhancer with multiple benefits, including improved soil fertility, potato performance, and effective management of potato cyst nematodes