A self-scanned 1024 element photodiode array and minicomputer are used to measure the phase (wavefront) in the interference pattern of an interferometer to lambda/100. The photodiode array samples intensities over a 32 x 32 matrix in the interference pattern as the length of the reference arm is varied piezoelectrically. Using these data the minicomputer synchronously detects the phase at each of the 1024 points by a Fourier series method and displays the wavefront in contour and perspective plot on a storage oscilloscope in less than 1 min (Bruning et al. Paper WE16, OSA Annual Meeting, Oct. 1972). The array of intensities is sampled and averaged many times in a random fashion so that the effects of air turbulence, vibrations, and thermal drifts are minimized. Very significant is the fact that wavefront errors in the interferometer are easily determined and may be automatically subtracted from current or subsequent wavefrots. Various programs supporting the measurement system include software for determining the aperture boundary, sum and difference of wavefronts, removal or insertion of tilt and focus errors, and routines for spatial manipulation of wavefronts. FFT programs transform wavefront data into point spread function and modulus and phase of the optical transfer function of lenses. Display programs plot these functions in contour and perspective. The system has been designed to optimize the collection of data to give higher than usual accuracy in measuring the individual elements and final performance of assembled diffraction limited optical systems, and furthermore, the short loop time of a few minutes makes the system an attractive alternative to constraints imposed by test glasses in the optical shop.

Mur, L. A. J., Aubry, S., Mondhe, M., Kingston-Smith, A. H., Gallagher, J. A., Timms-Taravella, E., James, C. L., Papp, I., Hortensteiner, S., Thomas, Howard, Ougham, H. J. (2010). Accumulation of chlorophyll catabolites photosensitizes the hypersensitive response elicited by Pseudomonas syringae in Arabidopsis. ? New Phytologist, 188 (1), 161-174. IMPF: 06.51 Sponsorship: Biotechnology and Biological Sciences Research Council (BBSRC)The staygreen (SGR) gene encodes a chloroplast-targeted protein which promotes chlorophyll degradation via disruption of light-harvesting complexes (LHCs). Over-expression of SGR in Arabidopsis (SGR-OX) in a Columbia-0 (Col-0) background caused spontaneous necrotic flecking. To relate this to the hypersensitive response (HR), Col-0, SGR-OX and RNAi SGR (SGRi) lines were challenged with Pseudomonas syringae pv tomato (Pst) encoding the avirulence gene avrRpm1. Increased and decreased SGR expression, respectively, accelerated and suppressed the kinetics of HR-cell death. In Col-0, SGR transcript increased at 6 h after inoculation (hai) when tissue electrolyte leakage indicated the initiation of cell death. Excitation of the chlorophyll catabolite pheophorbide (Pheide) leads to the formation of toxic singlet oxygen (1O2). Pheide was first detected at 6 hai with Pst avrRpm1 and was linked to 1O2 generation and correlated with reduced Pheide a oxygenase (PaO) protein concentrations. The maximum quantum efficiency of photosystem II (Fv/Fm), quantum yield of electron transfer at photosystem II (?PSII), and photochemical quenching (qP) decreased at 6 hai in Col-0 but not in SGRi. Disruption of photosynthetic electron flow will cause light-dependent H2O2 generation at 6 hai. We conclude that disruption of LHCs, possibly influenced by SGR, and absence of PaO produce phototoxic chlorophyll catabolites and oxidative stress leading to the HR.Peer reviewe

Antimycins are a family of natural products possessing outstanding biological activities and unique structures, which have intrigued chemists for over a half century. The antimycin structural skeleton is built on a nine-membered dilactone ring containing one alkyl, one acyloxy, two methyl moieties, and an amide linkage connecting to a 3-formamidosalicylic acid. Although a biosynthetic gene cluster for antimycins was recently identified, the enzymatic logic that governs the synthesis of antimycins has not yet been revealed. In this work, the biosynthetic pathway for antimycins was dissected by both genetic and enzymatic studies for the first time. A minimum set of enzymes needed for generation of the antimycin dilactone scaffold were identified, featuring a hybrid nonribosomal peptide synthetase (NRPS)-polyketide synthase (PKS) assembly line containing both cis- and trans-acting components. Several antimycin analogues were further produced using in vitro enzymatic total synthesis based on the substrate promiscuity of this NRPS-PKS machinery.

Leaf primary metabolism responds to changes in both supply of inputs and demand for products. Metabolic control in leaves changes both spatially and temporally. Using leaves of C(3) temperate Gramineae, the spatial control of carbohydrate metabolism has been studied using a range of approaches. Single-cell sampling and subsequent analysis of metabolites, proteins and transcripts has indicated significant differences between epidermal, mesophyll and parenchymatous bundle sheath cells. These differences correlate with differentiated function as heterotrophic, autotrophic and transport pathway components of the leaf. The review emphasizes the key role of sucrose and discusses its catabolism to hexoses and its anabolism to fructans as mechanisms for the preservation of sucrose gradients within the leaf.

This paper gives an overview of development of the EU-bioeconomy, 2014–2020. The Vision of the new Circular Bio-based Economy, CBE is presented: Unlocking the full potential of all types of sustainably sourced biomass, crop residues, industrial side-streams, and wastes by transforming it into value-added products. The resulting product portfolio consists of a wide spectrum of value-added products, addressing societal and consumer needs. Food and feed, bio-based chemicals, materials, health-promoting products; and bio-based fuels. The pillars of CBE are described, including biotechnology, microbial production, enzyme technology, green chemistry, integrated physical/chemical processing, policies, conducive framework conditions and public private partnerships. Drivers of CBE are analyzed: Biomass supply, biorefineries, value chain clusters, rural development, farmers, foresters and mariners; urgent need for climate change mitigation and adaptation, and stopping biodiversity loss. Improved framework conditions can be drivers but also obstacles if not updated to the era of circularity. Key figures, across the entire BBI-JU project portfolio (2014–2020) are provided, including expansion into biomass feedstocks, terrestrial and aquatic, and an impressive broadening of bio-based product portfolio, including higher-value, health-promoting products for man, animal, plants and soil. Parallel to this, diversification of industrial segments and types of funding instruments developed, reflecting industrial needs and academic research involvement. Impact assessment is highlighted. A number of specific recommendations are given; e.g., including international win/win CBE-collaborations, as e.g., expanding African EU collaboration into CBE. In contrast to fossil resources biological resources are found worldwide. In its outset, circular bio-based economy, can be implemented all over, in a just manner, not the least stimulating rural development.

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The invertases of Lolium temulentum have been characterized at the enzyme level. However, studies on the expression of the genes coding for these enzymes have been lacking. To elucidate the role of acid`invertase-like' genes in sucrose metabolism and carbon partitioning in Gramineae further, threè invertase-like' homologous clones were isolated from L. temulentum cDNA expression libraries based on leaf tissue, using maize soluble invertase probes. The effect of developmental stage and alterations in carbohydrate status on the expression and tissue distribution of these genes was investigated. The three highly homologous genes (Inv 1:2, Inv 1:4, and FT 2:2) show different patterns of expression and different tissue distribution. Inv 1:2 was predominantly expressed in root tissue. Expression increased during the dark in root and tiller base tissue. Minimal variations in gene expression were observed in leaf tissue following changes in carbohydrate status. Inv 1:4 was predominantly expressed in tiller bases, leaf sheath, and leaf base, with increased expression in tissue samples in the dark period. FT 2:2 was also predominantly expressed in tiller bases, leaf sheath, and leaf base. Higher expression was observed in leaf tissue following increases in carbohydrate content, in a manner that paralleled the regulation and spatial occurrence of fructan in the leaf tissue. Whilst invertases and fructosyltransferases are dif®cult to distinguish at the level of the whole sequence, analysis of 5¢ sequence and speci®c amino acids allows discrimination which correlates with patterns of expression within the tissue. Based on expression patterns and sequence characteristics, it is proposed that Inv 1:2 and Inv 1:4 code for soluble acid invertases, whilst FT 2:2 codes for a fructosyltransferase.

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