Global food systems will face unprecedented challenges in the coming years. They will need to meet the nutritional needs of a growing population and feed an expanding demand for proteins. This is against a backdrop of increasing environmental challenges (water resources, climate change, soil health) and the need to improve farming livelihoods.
View Article and Find Full Text PDFThe health and wellbeing of future generations will depend on humankind's ability to deliver sufficient nutritious food to a world population in excess of 9 billion. Feeding this many people by 2050 will require science-based solutions that address sustainable agricultural productivity and enable healthful dietary patterns in a more globally equitable way. This topic was the focus of a multi-disciplinary international conference hosted by Nestlé in June 2015, and provides the inspiration for the present article.
View Article and Find Full Text PDFArabidopsis (Arabidopsis thaliana) trichome development is a model system for studying cell development, cell differentiation, and the cell cycle. Our previous studies have shown that the GLABROUS INFLORESCENCE STEMS (GIS) family genes, GIS, GIS2, and ZINC FINGER PROTEIN8 (ZFP8), control shoot maturation and epidermal cell fate by integrating gibberellins (GAs) and cytokinin signaling in Arabidopsis. Here, we show that a new C2H2 zinc finger protein, ZFP5, plays an important role in controlling trichome cell development through GA signaling.
View Article and Find Full Text PDFThe purpose of the study was to evaluate the possible genetic effect on vegetative propagation of Coffea canephora. Diversity for somatic embryogenesis (SE) ability was observed not only among two groups of C. canephora Pierre (Congolese and Guinean), but also within these different genetic groups.
View Article and Find Full Text PDFPlant secretory trichomes have a unique capacity for chemical synthesis and secretion and have been described as biofactories for the production of natural products. However, until recently, most trichome-specific metabolic pathways and genes involved in various trichome developmental stages have remained unknown. Furthermore, only a very limited amount of plant trichome genomics information is available in scattered databases.
View Article and Find Full Text PDFThe diversification of chemical production in glandular trichomes is important in the development of resistance against pathogens and pests in two species of tomato. We have used genetic and genomic approaches to uncover some of the biochemical and molecular mechanisms that underlie the divergence in trichome metabolism between the wild species Solanum habrochaites LA1777 and its cultivated relative, Solanum lycopersicum. LA1777 produces high amounts of insecticidal sesquiterpene carboxylic acids (SCAs), whereas cultivated tomatoes lack SCAs and are more susceptible to pests.
View Article and Find Full Text PDFAcyl sugars containing branched-chain fatty acids (BCFAs) are exuded by glandular trichomes of many species in Solanaceae, having an important defensive role against insects. From isotope-feeding studies, two modes of BCFA elongation have been proposed: (1) fatty acid synthase-mediated two-carbon elongation in the high acyl sugar-producing tomato species Solanum pennellii and Datura metel; and (2) alpha-keto acid elongation-mediated one-carbon increments in several tobacco (Nicotiana) species and a Petunia species. To investigate the molecular mechanisms underlying BCFAs and acyl sugar production in trichomes, we have taken a comparative genomic approach to identify critical enzymatic steps followed by gene silencing and metabolite analysis in S.
View Article and Find Full Text PDFHop (Humulus lupulus L. Cannabaceae) is an economically important crop for the brewing industry, where it is used to impart flavor and aroma to beer, and has also drawn attention in recent years due to its potential pharmaceutical applications. Essential oils (mono- and sesquiterpenes), bitter acids (prenylated polyketides), and prenylflavonoids are the primary phytochemical components that account for these traits, and all accumulate at high concentrations in glandular trichomes of hop cones.
View Article and Find Full Text PDFGibberellins (GA) are known to influence phase change in Arabidopsis (Arabidopsis thaliana) as well as the development of trichomes, which are faithful epidermal markers of shoot maturation. They modulate these developmental programs in part by antagonizing DELLA repressors of growth, GIBBERELLIC ACID INSENSITIVE (GAI) and REPRESSOR OF ga1-3 (RGA). In this study, we have probed the relative roles played by RGA, GAI, and two homologs, RGA-LIKE1 (RGL1) and RGL2, in these processes and investigated molecular mechanisms through which they influence epidermal differentiation.
View Article and Find Full Text PDFThe effective integration of hormone signals is essential to normal plant growth and development. Gibberellins (GA) and cytokinins act antagonistically in leaf formation and meristem maintenance and GA counteract some of the effects of cytokinins on epidermal differentiation. However, both can stimulate the initiation of defensive epidermal structures called trichomes.
View Article and Find Full Text PDFThe composition and permeability of the cuticle has a large influence on its ability to protect the plant against various forms of biotic and abiotic stress. WAX INDUCER1 (WIN1) and related transcription factors have recently been shown to trigger wax production, enhance drought tolerance, and modulate cuticular permeability when overexpressed in Arabidopsis thaliana. We found that WIN1 influences the composition of cutin, a polyester that forms the backbone of the cuticle.
View Article and Find Full Text PDFAs a plant shoot matures, it transitions through a series of growth phases in which successive aerial organs undergo distinct developmental changes. This process of phase change is known to be influenced by gibberellins (GAs). We report the identification of a putative transcription factor, GLABROUS INFLORESCENCE STEMS (GIS), which regulates aspects of shoot maturation in Arabidopsis thaliana.
View Article and Find Full Text PDFSecondary metabolism is not only a protective mechanism against biotic and abiotic stresses but also part of the molecular programs that contribute to normal plant growth and development. In this context, secondary metabolism is intimately linked with other aspects of plant differentiation in which transcription factors play a key coordinating role. Recent findings illustrate the complexity of regulatory networks that control flavonoid biosynthesis in Arabidopsis and other species.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2004
Epicuticular wax forms a layer of hydrophobic material on plant aerial organs, which constitutes a protective barrier between the plant and its environment. We report here the identification of WIN1, an Arabidopsis thaliana ethylene response factor-type transcription factor, which can activate wax deposition in overexpressing plants. We constitutively expressed WIN1 in transgenic Arabidopsis plants, and found that leaf epidermal wax accumulation was up to 4.
View Article and Find Full Text PDFThe functions of an increasing number of plant transcription factors are being elucidated, and many of these factors have been found to impact flux through metabolic pathways. Because transcription factors, as opposed to most structural genes, tend to control multiple pathway steps, they have emerged as powerful tools for the manipulation of complex metabolic pathways in plants. The review describes the highlights of recent experiments that have targeted transcription factors that control plant metabolic pathways, and discusses their potential as tools for metabolic engineering.
View Article and Find Full Text PDFThe completion of the Arabidopsis thaliana genome sequence allows a comparative analysis of transcriptional regulators across the three eukaryotic kingdoms. Arabidopsis dedicates over 5% of its genome to code for more than 1500 transcription factors, about 45% of which are from families specific to plants. Arabidopsis transcription factors that belong to families common to all eukaryotes do not share significant similarity with those of the other kingdoms beyond the conserved DNA binding domains, many of which have been arranged in combinations specific to each lineage.
View Article and Find Full Text PDFVegetable oils are a major component of human diets, comprising as much as 25% of average caloric intake. Until recently, it was not possible to exert significant control over the chemical composition of vegetable oils derived from different plants. However, the advent of genetic engineering has provided novel opportunities to tailor the composition of plant-derived lipids so that they are optimized with respect to food functionality and human dietary needs.
View Article and Find Full Text PDFHigher plants exhibit extensive diversity in the composition of seed storage fatty acids. This is largely due to the presence of various combinations of double or triple bonds and hydroxyl or epoxy groups, which are synthesized by a family of structurally similar enzymes. As few as four amino acid substitutions can convert an oleate 12-desaturase to a hydroxylase and as few as six result in conversion of a hydroxylase to a desaturase.
View Article and Find Full Text PDFLFAH12, an oleate 12-hydroxylase gene from Lesquerella fendleri (L.) was isolated on the basis of nucleotide sequence similarity to an oleate hydroxylase gene from Ricinus communis (L.).
View Article and Find Full Text PDFA cDNA encoding the oleate 12-hydroxylase from castor bean (Ricinus communis L.) has previously been shown to direct the synthesis of small amounts of ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) in seeds of transgenic tobacco plants. Expression of the cDNA under control of the Brassica napus napin promoter in transgenic Arabidopsis thaliana plants resulted in the accumulation of up to 17% of seed fatty acids as ricinoleate and two novel fatty acids that have been identified by gas chromatography-mass spectrometry as lesquerolic (14-hydroxyeicos-cis-11-enoic acid) and densipolic (12-hydroxyoctadec-cis-9,15-dienoic acid) acids.
View Article and Find Full Text PDFMol Gen Genet
January 1996
Tomato genomic libraries were screened for the presence of simple sequence repeats (SSRs) with seventeen synthetic oligonucleotide probes, consisting of 2- to 5-basepair motifs repeated in tandem. GAn and GTn sequences were found to occur most frequently in the tomato genome (every 1.2 Mb), followed by ATTn and GCCn (every 1.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 1995
Recent spectroscopic evidence implicating a binuclear iron site at the reaction center of fatty acyl desaturases suggested to us that certain fatty acyl hydroxylases may share significant amino acid sequence similarity with desaturases. To test this theory, we prepared a cDNA library from developing endosperm of the castor-oil plant (Ricinus communis L.) and obtained partial nucleotide sequences for 468 anonymous clones that were not expressed at high levels in leaves, a tissue deficient in 12-hydroxyoleic acid.
View Article and Find Full Text PDFA tomato lambda genomic library was screened with the human minisatellites 33.6 and 33.15.
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