Advances in heterometallic ring-opening (co)polymerisation catalysis

Truly sustainable plastics require renewable feedstocks coupled with efficient production and end-of-life degradation/recycling processes. Some of the most useful degradable materials are aliphatic polyesters, polycarbonates and polyamides, which are often prepared via ring-opening (co)polymerisation (RO(CO)P) using an organometallic catalyst. While there has been extensive research into ligand development, heterometallic cooperativity offers an equally promising yet underexplored strategy to improve catalyst performance, as heterometallic catalysts often exhibit significant activity and selectivity enhancements compared to their homometallic counterparts. This review describes advances in heterometallic RO(CO)P catalyst design, highlighting the overarching structure-activity trends and reactivity patterns to inform future catalyst design

Airborne Signals from a Wounded Leaf Facilitate Viral Spreading and Induce Antibacterial Resistance in Neighboring Plants

Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. Here, we study the effects of pectin methylesterase (PME)-generated methanol release from wounded plants (“emitters”) on the defensive reactions of neighboring “receiver” plants. Plant leaf wounding resulted in the synthesis of PME and a spike in methanol released into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. In experiments with different volatile organic compounds, gaseous methanol was the only airborne factor that could induce antibacterial resistance in neighboring plants. In an effort to understand the mechanisms by which methanol stimulates the antibacterial resistance of “receiver” plants, we constructed forward and reverse suppression subtractive hybridization cDNA libraries from Nicotiana benthamiana plants exposed to methanol. We identified multiple methanol-inducible genes (MIGs), most of which are involved in defense or cell-to-cell trafficking. We then isolated the most affected genes for further analysis: β-1,3-glucanase (BG), a previously unidentified gene (MIG-21), and non-cell-autonomous pathway protein (NCAPP). Experiments with Tobacco mosaic virus (TMV) and a vector encoding two tandem copies of green fluorescent protein as a tracer of cell-to-cell movement showed the increased gating capacity of plasmodesmata in the presence of BG, MIG-21, and NCAPP. The increased gating capacity is accompanied by enhanced TMV reproduction in the “receivers”. Overall, our data indicate that methanol emitted by a wounded plant acts as a signal that enhances antibacterial resistance and facilitates viral spread in neighboring plants

Semiochemical-based alternatives to synthetic toxicant insecticides for pollen beetle management

There is an urgent need to develop sustainable pest management systems to protect arable crops in order to replace the current over-reliance on synthetic insecticides. Semiochemicals are insect- or plant-derived chemicals that are used by organisms as information signals. Integrated pest management tools are currently in development that utilise semiochemicals to manipulate the behaviour of pest insects and their natural enemies to provide effective control of pests within the crop. These innovative tools usually require fewer inputs and can involve multiple elements therefore reducing the likelihood of resistance developing compared with use of synthetic toxicants. We review here the life cycle of the pollen beetle Brassicogethes aeneus (previously known as Meligethes aeneus) which is a pest insect of oilseed rape (Brassica napus) and describe the current knowledge of any behaviour mediated by semiochemicals in this species. We discuss the behavioural processes where semiochemical-based control approaches may be appropriate and consider how these approaches could be integrated into an integrated pest management strategy for this important arable crop

Architecture, Space and Information in Constructions Built by Humans and Social Insects: a Conceptual Review

The similarities between the structures built by social insects and by humans have led to a convergence of interests between biologists and architects. This new, de facto interdisciplinary community of scholars needs a common terminology and theoretical framework in which to ground its work. In this conceptually oriented review paper, we review the terms “information”, “space” and “architecture” to provide definitions that span biology and architecture. A framework is proposed on which interdisciplinary exchange may be better served, with the view that this will aid better cross fertilisation between disciplines, working in the areas of collective behaviour and analysis of the structures and edifices constructed by non-humans; and to facilitate how this area of study may better contribute to the field of architecture. We then use these definitions to discuss the informational content of constructions built by organisms and the influence these have on behaviour, and vice versa. We review how spatial constraints inform and influence interaction between an organism and its environment, and examine the reciprocity of space and information on construction and the behaviour of humans and social insects

Elevated temperatures drive the evolution of armour loss in the threespine stickleback Gasterosteus aculeatus

1. While there is evidence of genetic and phenotypic responses to climate change, few studies have demonstrated change in functional traits with a known genetic basis. 2. Here we present evidence for an evolutionary adaptive response to elevated temperatures in freshwater populations of the threespine stickleback Gasterosteus aculeatus. 3. Using a unique set of historical data and museum specimens, in combination with contemporary samples, we fitted a Bayesian spatial model to identify a population-level decline in the number of lateral bony plates, comprising anti-predator armour, in multiple populations of sticklebacks over the last 91 years in Poland. 4. Armor loss was predicted by elevated temperatures and is proposed to be a correlated response to selection for reduced body size. 5. This study demonstrates a change in a functional trait of known genetic basis in response to elevated temperature, and illustrates the utility of the threespine stickleback as a model for measuring the evolutionary and ecological impacts of environmental change across the northern hemisphere

Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?

peer reviewedBackground Aboveground, plants release volatile organic compounds (VOCs) that act as chemical signals between neighbouring plants. It is now well documented that VOCs emitted by the roots in the plant rhizosphere also play important ecological roles in the soil ecosystem, notably in plant defence because they are involved in interactions between plants, phytophagous pests and organisms of the third trophic level. The roles played by root-emitted VOCs in between- and within-plant signalling, however, are still poorly documented in the scientific literature. Scope Given that (1) plants release volatile cues mediating plant-plant interactions aboveground, (2) roots can detect the chemical signals originating from their neighbours, and (3) roots release VOCs involved in biotic interactions belowground, the aim of this paper is to discuss the roles of VOCs in between- and within-plant signalling belowground. We also highlight the technical challenges associated with the analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated root-root interactions. Conclusions We conclude that root-root interactions mediated by volatile cues deserve more research attention and that both the analytical tools and methods developed to study the ecological roles played by VOCs in interplant signalling aboveground can be adapted to focus on the roles played by root-emitted VOCs in between- and within-plant signalling

Effect of sprinkling irrigation and varied nitrogen fertilization of millet cv. Gierczyckie on occurrence of phytophagous entomofauna

Badano wpływ nawadniania oraz nawożenia azotowego prosa odmiany ‘Gierczyckie’ na występowanie fitofagicznej entomofauny o kłująco-ssącym aparacie gębowym. Doświadczenie polowe prowadzono w latach 2005-2006 w Kruszynie Krajeńskim koło Bydgoszczy. Stwierdzono, że przylżeńce oraz pluskwiaki stanowiły najliczniejszą grupę, która zasiedlała rośliny prosa. Odławiano zdecydowanie najmniejszą liczebność thysanopterofauny, gdy rośliny traktowano średnimi dawkami nawożenia azotowego. Owady te preferowały rośliny nawadniane. Kwietniczkowate (Phlaeothripidae) stanowiły zdecydowanie najliczniejszą grupę owadów odławianych spośród przylżeńców. Liczebność odławianych pluskwiaków była niższa, w porównaniu do przylżeńców. Hemiptera najliczniej występowały na roślinach nawadnianych, które traktowano wysokim poziomem nawożenia azotowego. Reprezentowane one były przez kilka rodzin, takich jak: skoczkowate, tasznikowate, mszycowate i szydlakowate. Najliczniejszym przedstawicielem Cicadellidae był zgłobik smużkowany – Psammotettix alienus Dahlbom. Skoczek sześciorek – Macrosteles laevis Ribaut oraz skoczek ziemniaczak – Empoasca pteridis Dahlbom wystąpiły w nieco mniejszym nasileniu. Spośród rodziny mszycowatych najliczniej odławiano mszycę zbożową i mszycę czeremchowo-zbożową. Stosowanie zróżnicowanego nawadniania oraz nawożenia azotowego w uprawie prosa wpływało na liczebność fitofagicznych pluskwiaków z rodziny tasznikowatych: zmienika lucernowca - Lygus rugulipennis Popp. i wysmułka paskorogiego - Trigonotylus coelestialiumKirk. Pierwszy z wymienionych Miridae zdecydowanie preferował rośliny nawadniane oraz nawożone wyższą dawką azotu.The sprinkling irrigation and varied nitrogen fertilisation of millet cv. Gierczyckie on insects with the hemipteroidal mouthpart occurrence were investigated. The entomological experiments were conducted in 2005 and 2006 in Kruszyn Krajeński near Bydgoszcz. The largest group of insects were Thysanoptera and Hemiptera. When we used the middle rate of nitrogen fertilization, Thysanoptera was significantly less numerous. They preffered the irrigation plants. From Thysanoptera the most abundant were Phlaeothripidae. Number of Hemiptera was significantly less than Thysanoptera. When the high rate of nitrogen fertilization was used, the numer of Hemiptera was high, too. They were represented by Cicadellidae, Miridae, Aphididae and Delphacidae families. Psammotettix alienus Dahlbom. was the most numerous insects from Cicadellidae. The numbers of Macrosteles laevis Ribaut and Empoasca pteridis Dahlbom was lower. The most frequently caught of Aphididae were the following insects: Sitobion avenae (F.) H.R.L. and Rhopalosiphum padi L. The usage of irrigation and varied nitrogen fertilization in millet cultivation, affected on numerous of phytophagous insects such as: Lygus rugulipennis Popp. and Trigonotylus coelestialium Kirk. First of theirs preffered irrigation plants with higher rate of nitrogen fertilization