| 1. |
- Becher, Paul G., et al.
(författare)
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Chemical signaling and insect attraction is a conserved trait in yeasts
- 2018
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; , s. 2962-2974
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Tidskriftsartikel (refereegranskat)abstract
- Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae, the insect-associated species Candida californica, Pichia kluyveri and Metschnikowia andauensis, wine yeast Dekkera bruxellensis, milk yeast Kluyveromyces lactis, the vertebrate pathogens Candida albicans and Candida glabrata, and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila, we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts. Moreover, volatiles emitted by yeasts are commonly found also in flowers and attract many insect species. The collective evidence suggests that the release of volatile signals by yeasts is a widespread and phylogenetically ancient trait, and that insect-yeast communication evolved prior to the emergence of flowering plants. Co-occurrence of the same attractant signals in yeast and flowers suggests that yeast-insect communication may have contributed to the evolution of insect-mediated pollination in flowers.
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| 2. |
- Borrero, Felipe, et al.
(författare)
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Yeast Volatomes Differentially Affect Larval Feeding in an Insect Herbivore
- 2019
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 85
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Tidskriftsartikel (refereegranskat)abstract
- Yeasts form mutualistic interactions with insects. Hallmarks of this interaction include provision of essential nutrients, while insects facilitate yeast dispersal and growth on plant substrates. A phylogenetically ancient chemical dialogue coordinates this interaction, where the vocabulary, the volatile chemicals that mediate the insect response, remains largely unknown. Here, we used gas chromatography-mass spectrometry, followed by hierarchical cluster and orthogonal partial least-squares discriminant analyses, to profile the volatomes of six Metschnikowia spp., Cryptococcus nemorosus, and brewer's yeast (Saccharomyces cerevisiae). The yeasts, which are all found in association with insects feeding on foliage or fruit, emit characteristic, species-specific volatile blends that reflect the phylogenetic context. Species specificity of these volatome profiles aligned with differential feeding of cotton leafworm (Spodoprera littoralis) larvae on these yeasts. Bioactivity correlates with yeast ecology; phylloplane species elicited a stronger response than fruit yeasts, and larval discrimination may provide a mechanism for establishment of insect-yeast associations. The yeast volatomes contained a suite of insect attractants known from plant and especially floral headspace, including (Z)-hexenyl acetate, ethyl (2E,4Z)-deca-2,4-dienoate (pear ester), (3E)-4,8-dimethylnona-1,3,7-triene (DMNT), linalool, alpha-terpineol, beta-myrcene, or (E,E)-alpha-farnesene. A wide overlap of yeast and plant volatiles, notably floral scents, further emphasizes the prominent role of yeasts in plant-microbe-insect relationships, including pollination. The knowledge of insect-yeast interactions can be readily brought to practical application, as live yeasts or yeast metabolites mediating insect attraction provide an ample tool-box for the development of sustainable insect management.IMPORTANCE Yeasts interface insect herbivores with their food plants. Communication depends on volatile metabolites, and decoding this chemical dialogue is key to understanding the ecology of insect-yeast interactions. This study explores the volatomes of eight yeast species which have been isolated from foliage, from flowers or fruit, and from plant-feeding insects. These yeasts each release a rich bouquet of volatile metabolites, including a suite of known insect attractants from plant and floral scent. This overlap underlines the phylogenetic dimension of insect-yeast associations, which according to the fossil record long predate the appearance of flowering plants. Volatome composition is characteristic for each species, aligns with yeast taxonomy, and is further reflected by a differential behavioral response of cotton leafworm larvae, which naturally feed on foliage of a wide spectrum of broad-leaved plants. Larval discrimination may establish and maintain associations with yeasts and is also a substrate for designing sustainable insect management techniques.
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| 3. |
- Chakraborty, Amrita
(författare)
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Microbial Influence on Plant-Insect Interaction
- 2021
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Ingår i: Plant-Pest Interactions: From Molecular Mechanisms to Chemical Ecology. - Singapore : Springer Singapore. - 9789811524660 ; , s. 337-363
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Bokkapitel (refereegranskat)abstract
- Plants and insects live in a microbial world, and the co-existence have shaped their ecology and evolution. These microbial allies play an essential role in the health, well-being, and vigor of their hosts and are often considered as “hidden players” in plant-insect interaction. The present chapter attempts to cover the contribution of microbes as drivers of plant-insect interaction where the microbial companions directly or indirectly influence the plant-insect interaction. The chapter also emphasizes the diversity of microbial communities linked with both plants and insects and their contribution toward plant-insect interaction from an ecological standpoint. It further deals with the recent updates on the use of microorganisms in pest management and the implications of microbes as a toolbox in future IPM strategies.
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| 4. |
- Chakraborty, Amrita
(författare)
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Natural Insecticidal Proteins and Their Potential in Future IPM
- 2021
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Ingår i: Plant-Pest Interactions: From Molecular Mechanisms to Chemical Ecology : Chemical Ecology. - Singapore : Springer Singapore. - 9789811524660 ; , s. 265-303
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Bokkapitel (refereegranskat)abstract
- Increasing population and global food security is the foremost challenge for this century. Insect pests cause substantial damage to our crops by direct as well as indirect means such as vectoring plant viruses. Introduction of Bacillus thuringiensis originated toxins, namely, cry toxins, in the crop plants that showed significant resistance to insect damage during the early years (1990s). However, its societal unacceptability, nontarget effects, and the frequent development of resistance in target insects jeopardize Cry-toxin-mediated pest resistance. Alternatively, plant proteins with insecticidal activity hold great potential for future insect pest management strategies (IPM). Present chapter mainly deals with the ongoing advances in research on plant lectins. However, the entomotoxic potential of other plant proteins such as digestive inhibitors and plant peptides is also stated briefly. Further, future challenges and possibilities for developing sustainable pest management strategies are also discussed.
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| 5. |
- Chakraborty, Amrita, et al.
(författare)
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Yeast and fruit fly mutual niche construction and antagonism against mould
- 2022
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Ingår i: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 36:7, s. 1639-1654
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Tidskriftsartikel (refereegranskat)abstract
- A goal in insect–microbe ecology is to understand the mechanisms regulating species associations and mutualistic interactions. The spotted wing drosophila Drosophila suzukii develops in ripening fruit, unlike other drosophilids that typically feed on overripe fruit, and is associated with the yeast Hanseniaspora uvarum. We hypothesized that D. suzukii and H. uvarum engage in niche construction leading to a mutualistic relation, facilitating the exploitation of fruit and berries as larval substrate. We show that H. uvarum proliferates on both ripe and on unripe raspberries, mediates attraction of D. suzukii larvae and adult flies, enhances egg-laying in mated females and is a sufficient food substrate to support larval development. Moreover, H. uvarum suppresses the antagonistic grey mould, Botrytis cinerea in collaboration with D. suzukii larvae, and produces less ethanol than baker's yeast. H. uvarum thus creates favourable conditions for D. suzukii larval development, which is susceptible to ethanol and grey mould. D. suzukii, on the other hand, vectors H. uvarum to suitable substrates such as raspberries, where larval feeding activity enhances growth of H. uvarum. Larval feeding also helps to suppress B. cinerea, which otherwise outcompetes H. uvarum on raspberry, in the absence of fly larvae. In conclusion, H. uvarum enhances D. suzukii larval development on unripe berries, and D. suzukii promotes H. uvarum dispersal and growth on berries. Yeast and fly modify their shared habitat in reciprocal niche construction and mutual interaction. Read the free Plain Language Summary for this article on the Journal blog.
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| 6. |
- Powell, Daniel, et al.
(författare)
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A highly-contiguous genome assembly of the Eurasian spruce bark beetle, Ips typographus, provides insight into a major forest pest
- 2021
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Conifer-feeding bark beetles are important herbivores and decomposers in forest ecosystems. These species complete their life cycle in nutritionally poor substrates and some can kill enormous numbers of trees during population outbreaks. The Eurasian spruce bark beetle (Ips typographus) can destroy >100 million m3 of spruce in a single year. We report a 236.8 Mb I. typographus genome assembly using PacBio long-read sequencing. The final phased assembly has a contig N50 of 6.65 Mb in 272 contigs and is predicted to contain 23,923 protein-coding genes. We reveal expanded gene families associated with plant cell wall degradation, including pectinases, aspartyl proteases, and glycosyl hydrolases. This genome sequence from the genus Ips provides timely resources to address questions about the evolutionary biology of the true weevils (Curculionidae), one of the most species-rich animal families. In forests of today, increasingly stressed by global warming, this draft genome may assist in developing pest control strategies to mitigate outbreaks.
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| 7. |
- Singh, Shivam, et al.
(författare)
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Investigation on Organic Molecule Additive for Moisture Stability and Defect Passivation via Physisorption in CH3NH3PbI3 Based Perovskite
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:5, s. 1870-1877
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the role of n-type organic molecule, bathocuproine (BCP), additive in perovskite semiconductor film based solar cells using first principle calculations and optoelectronic studies. A state-of-art high fill factor of 0.82 and improved open circuit voltage of 0.95 V for CH3NH3PbI3 (MAPI) based perovskite solar cells are achieved in addition with highly improved (more than one order) electroluminescence efficiency. Delayed emission spectroscopy does not show any blue shift peak or double peak emission suggests no structural changes in 3D perovskite. Contact angle studies using water droplet supports BCP is forming a capping layer to boost moisture barrier. Our experimental findings regarding no 2D structure formation has also been supported by first-principles electronic structure calculations based on DFT in MAPI after insertion of BCP. Furthermore, calculations suggest that a physisorption type of interaction has been found in between MAPI and BCP with an average distance of 2.9 angstrom. These results were found to be in agreement with steady-state and transient photoluminescence studies where an improved PL is observed by using perovskite solution with BCP additive. Chemical analysis and electroluminescence study confirmed the reduction in defect sites by BCP addition. The study suggests that BCP being a small molecule plays an important role in passivating and improving the MAPI film quality and points to an approach toward utilizing other such additives. Furthermore, this approach can be useful for other optoelectronic devices too based on wider bandgap perovskite semiconductors.
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