https://hdl.handle.net/10182/38 Thu, 25 Jan 2018 15:18:40 GMT 2018-01-25T15:18:40Z https://hdl.handle.net/10182/8941 A comparative survey of small RNA and their targets in grapevine embryogenic callus cultures and young leaves Lizamore, Darrell; Winefield, Christopher S. Plant embryogenic callus (EC) cultures are important both for clonal propagation and as a source of explant material for transgenesis experiments. In grapevine, much work has been done to develop protocols for establishing EC cultures from multiple varieties. However, tissue culture provides a stress effect that can alter both to the genome, through the activation of transposable elements, and the epigenome. The host cell response to genomic stress is two-fold: post-transcriptional gene silencing (PTGS) targets aberrant transcripts for cleavage and sequestration, and transcriptional gene silencing (TGS) targets specific DNA loci for RNA dependent DNA methylation (RdDM) and histone modifications. Small RNA molecules direct these systems to their targets based on sequence complementarity. To better understand silencing activity in EC cultures, we undertook a survey molecules of small from these cultures using parallel short read sequencing and compared these with small RNA from young leaf tissue. Our results show that small RNA profiles differ greatly among the two tissue types. One third of the small RNAs found in leaf were known microRNA (miRNA) sequences that regulate the development of vegetative tissue. MicroRNAs were also present in EC, but comprised less than one per cent of the small RNA complement. Comparison of the gene ontology (GO) networks of target genes for each sample revealed complex and distinct patterns of gene regulation in each tissue type. Trans-acting siRNAs (tasiRNAs) from 18 loci were also present at over 100 reads per million (RPM) in leaf, all of which were decreased or absent in EC. In contrast, EC contained approximately twice the amount of 24 nt small interfering RNAs (siRNAs) associated with maintaining the repression of repeat-associated DNA as was found in the leaf tissue. The results indicate that not only do the targets of RNA interference (RNAi) vary in EC with respect to leaf tissue, but that the levels of activity for the various silencing systems differ greatly. Researchers studying plants recovered through somatic embryogenesis would be advised to take these observations into consideration, particularly when the introduction of foreign DNA is involved. Thu, 30 Nov 2017 00:00:00 GMT https://hdl.handle.net/10182/8941 2017-11-30T00:00:00Z https://hdl.handle.net/10182/8909 The role of protein and starch of legumes and cereals on the formation of healthy snack products Patil, Swapnil Proteins, vitamins, minerals and carbohydrates are important nutrients that play vital role in human metabolism. Cereals and Legumes are significant source of protein, dietary fiber, carbohydrates and dietary minerals. They are also an excellent source of essential amino acid lysine. Unfortunately, legume seeds that grow in New Zealand are considered as a low value crop and mainly used in animal feed production. However, we believe that combinations of legumes and cereals grown in New Zealand could be used as a value added food ingredient for products. On the other hand there has been increased attention in the utilization of non-meat protein rich food materials for food products. This may be due to their potential to control postprandial protein digestibility and glycaemic response of individuals. However, there is limited data available on the efficacy of legume and cereal that grown in New Zealand on the protein and carbohydrate digestibility. The main aim of this research project is to evaluate the potential of using blends of legume and cereal materials as a snack product on the manipulation of protein and carbohydrate digestibility in human. This project will advance knowledge of the transfer of processing and biochemical research to the food industry and thus the creation of a value added food chain for New Zealand grown legumes and cereals as processed snack products. Tue, 07 Nov 2017 00:00:00 GMT https://hdl.handle.net/10182/8909 2017-11-07T00:00:00Z https://hdl.handle.net/10182/8893 The application of high-resolution atmospheric modelling to weather and climate variability in vineyard regions Sturman, A.; Zawar-Reza, P.; Soltanzadeh, I.; Katurji, M.; Bonnardot, V.; Parker, Amber; Trought, Michael C.; Quénol, H.; Le Roux, R.; Gendig, E.; Schulmann, T. Grapevines are highly sensitive to environmental conditions, with variability in weather and climate (particularly temperature) having a significant influence on wine quality, quantity and style. Improved knowledge of spatial and temporal variations in climate and their impact on grapevine response allows better decision-making to help maintain a sustainable wine industry in the context of medium to long term climate change. This paper describes recent research into the application of mesoscale weather and climate models that aims to improve our understanding of climate variability at high spatial (1 km and less) and temporal (hourly) resolution within vineyard regions of varying terrain complexity. The Weather Research and Forecasting (WRF) model has been used to simulate the weather and climate in the complex terrain of the Marlborough region of New Zealand. The performance of the WRF model in reproducing the temperature variability across vineyard regions is assessed through comparison with automatic weather stations. Coupling the atmospheric model with bioclimatic indices and phenological models (e.g. Huglin, cool nights, Grapevine Flowering Véraison model) also provides useful insights into grapevine response to spatial variability of climate during the growing season, as well as assessment of spatial variability in the optimal climate conditions for specific grape varieties. Mon, 15 May 2017 00:00:00 GMT https://hdl.handle.net/10182/8893 2017-05-15T00:00:00Z https://hdl.handle.net/10182/8852 Conservation of complete trimethylation of lysine-43 in the rotor ring of c-subunits of metazoan adenosine triphosphate (ATP) synthases Walpole, T. B.; Palmer, David N.; Jiang, Huibing; Ding, S.; Fearnley, I. M.; Walker, J. E. The rotors of ATP synthases turn about 100 times every second. One essential component of the rotor is a ring of hydrophobic c-subunits in the membrane domain of the enzyme. The rotation of these c-rings is driven by a transmembrane proton-motive force, and they turn against a surface provided by another membrane protein, known as subunit a. Together, the rotating c-ring and the static subunit a provide a pathway for protons through the membrane in which the c-ring and subunit a are embedded. Vertebrate and invertebrate c-subunits are well conserved. In the structure of the bovine F₁-ATPase-c-ring subcomplex, the 75 amino acid c-subunit is folded into two transmembrane α-helices linked by a short loop. Each bovine rotor-ring consists of eight c-subunits with the N- and C-terminal α-helices forming concentric inner and outer rings, with the loop regions exposed to the phospholipid head-group region on the matrix side of the inner membrane. Lysine-43 is in the loop region and its ε-amino group is completely trimethylated. The role of this modification is unknown. If the trimethylated lysine-43 plays some important role in the functioning, assembly or degradation of the c-ring, it would be expected to persist throughout vertebrates and possibly invertebrates also. Therefore, we have carried out a proteomic analysis of c-subunits across representative species from different classes of vertebrates and from invertebrate phyla. In the twenty-nine metazoan species that have been examined, the complete methylation of lysine-43 is conserved, and it is likely to be conserved throughout the more than two million extant metazoan species. In unicellular eukaryotes and prokaryotes, when the lysine is conserved it is unmethylated, and the stoichiometries of c-subunits vary from 9-15. One possible role for the trimethylated residue is to provide a site for the specific binding of cardiolipin, an essential component of ATP synthases in mitochondria. Wed, 01 Apr 2015 00:00:00 GMT https://hdl.handle.net/10182/8852 2015-04-01T00:00:00Z