Pinoxaden resistance was observed before pinoxaden release in France. Only a fraction of the mechanisms endowing fenoxaprop or clodinafop resistance also confer pinoxaden resistance. Pinoxaden resistance was likely mostly selected for by ACCase inhibitors, and, in some cases, possibly by herbicides with other modes of action. This illustrates the necessity to use metabolisable herbicides cautiously where black-grass has evolved non-target-site-based resistance.

Animals use the chemical compounds of plants as a defence mechanism against enemies, and sometimes use olfaction to discriminate and select the chemical plant substances. Some birds bring to the nest plant material that has volatile compounds that protect the host and their offspring against parasitic organisms. Here we show that blue tits on the island of Corsica (Parus caeruleus ogliastrae) adorn their nests with fragments of aromatic plants. These plants have chemical compounds that are used by humans to make aromatic house cleaners and herbal medicines. We also show that individual blue tits maintain an aromatic nest environment when offspring are raised, using odour cues to determine the frequency with which they replenish the nest with fresh plant material. We provide an exceptional example of the ecologically relevant use of olfaction by birds under natural conditions. To our knowledge, we present the first experimental demonstration that a free‐ranging animal makes use of smell to maintain an aromatic environment for offspring with plants, supporting predictions of the nest protection hypothesis.

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Délye C, Gardin JAC, Boucansaud K, Chauvel B & Petit C (2011). Non‐target‐site‐based resistance should be the centre of attention for herbicide resistance research: Alopecurus myosuroides as an illustration. Weed Research51, 433–437. Summary Non‐target‐site‐based resistance (NTSR) mechanisms can confer unpredictable resistance to herbicides with different chemistries or modes of action. In two French fields, 18% and 40% individual plants of Alopecurus myosuroides (black‐grass), respectively, were resistant via NTSR to all the most effective herbicides approved for A. myosuroides control in wheat (fenoxaprop, clodinafop, pinoxaden, iodosulfuron+mesosulfuron and pyroxsulam) and to the broad‐leaf‐selective herbicide quizalofop. Pinoxaden and pyroxsulam had never been applied to these populations. In the absence of new herbicide modes of action, this renders a purely chemical control of A. myosuroides in winter cereals much more complex in these fields. A segregation analysis showed that multi‐resistant phenotypes were endowed by multiple NTSR genes, underlining the complexity of NTSR. Yet, despite the threat posed to weed control, our lack of knowledge on NTSR is obvious. NTSR should therefore become the priority in herbicide resistance research.

The reduction mechanism of tertiary phosphine oxides by Ti(OiPr)4/hydrosiloxane was studied. Strong improvement was achieved using a drying agent. ESR spectra of the reaction mixture give evidence for a single electronic transfer (SET) mechanism.

The unique cell wall of mycobacteria is essential to their viability and the target of many clinically used anti-tuberculosis drugs and inhibitors under development. Despite intensive efforts to identify the ligase(s) responsible for the covalent attachment of the two major heteropolysaccharides of the mycobacterial cell wall, arabinogalactan (AG) and peptidoglycan (PG), the enzyme or enzymes responsible have remained elusive. We here report on the identification of the two enzymes of Mycobacterium tuberculosis, CpsA1 (Rv3267) and CpsA2 (Rv3484), responsible for this function. CpsA1 and CpsA2 belong to the widespread LytR-Cps2A-Psr (LCP) family of enzymes that has been shown to catalyze a variety of glycopolymer transfer reactions in Gram-positive bacteria, including the attachment of wall teichoic acids to PG. Although individual cpsA1 and cpsA2 knock-outs of M. tuberculosis were readily obtained, the combined inactivation of both genes appears to be lethal. In the closely related microorganism Corynebacterium glutamicum, the ortholog of cpsA1 is the only gene involved in this function, and its conditional knockdown leads to dramatic changes in the cell wall composition and morphology of the bacteria due to extensive shedding of cell wall material in the culture medium as a result of defective attachment of AG to PG. This work marks an important step in our understanding of the biogenesis of the unique cell envelope of mycobacteria and opens new opportunities for drug development.

The palladium-catalyzed cross-coupling reaction between H-phosphinate esters and chloroarenes or chloroheteroarenes is described. This reaction is the first general metal-catalyzed phosphorus-carbon bond-forming reaction between a phosphorus nucleophile and chloroarenes.

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