Genetically modified (GM) crops offer significant advantages in our crop improvement programs because they are created using a more targeted approach which is not possible in traditional breeding methods. Human benefit is one of the main objectives of crop improvement but the legal framework for the introduction of GM crops and the depiction and portrayal of GM crops in the media create barriers to these benefits. This article attempts to highlight the barriers to GM crop adoption particularly focusing on the idea of "framing" and the way GM technology is framed in the media.
View Article and Find Full Text PDFDrought is an important constraint to agricultural productivity worldwide and is expected to worsen with climate change. To assist farmers, especially in sub-Saharan Africa (SSA), to adapt to climate change, continuous generation of stress-tolerant and farmer-preferred crop varieties, and their adoption by farmers, is critical to curb food insecurity. Maize is the most widely grown staple crop in SSA and plays a significant role in food security.
View Article and Find Full Text PDFSterols are integral components of membrane lipid bilayers in eukaryotic organisms and serve as precursors to steroid hormones in vertebrates and brassinosteroids (BR) in plants. In vertebrates, cholesterol is the terminal sterol serving both indirect and direct roles in cell signaling. Plants synthesize a mixture of sterols including cholesterol, sitosterol, campesterol, and stigmasterol but the signaling role for the free forms of individual plant sterols is unclear.
View Article and Find Full Text PDFA direct role for cholesterol signaling in mammals is clearly established; yet, the direct role in signaling for a plant sterol or sterol precursor is unclear. Fluctuations in sitosterol and stigmasterol levels during development and stress conditions suggest their involvement in signaling activities essential for plant development and stress compensation. Stigmasterol may be involved in gravitropism and tolerance to abiotic stress.
View Article and Find Full Text PDFMaize has for many decades been both one of the most important crops worldwide and one of the primary genetic model organisms. More recently, maize breeding has been impacted by rapid technological advances in sequencing and genotyping technology, transformation including genome editing, doubled haploid technology, parallelled by progress in data sciences and the development of novel breeding approaches utilizing genomic information. Herein, we report on past, current and future developments relevant for maize breeding with regard to (1) genome analysis, (2) germplasm diversity characterization and utilization, (3) manipulation of genetic diversity by transformation and genome editing, (4) inbred line development and hybrid seed production, (5) understanding and prediction of hybrid performance, (6) breeding methodology and (7) synthesis of opportunities and challenges for future maize breeding.
View Article and Find Full Text PDFReact Oxyg Species (Apex)
November 2017
L-Ascorbic acid (AsA, vitamin C) is an essential antioxidant for plants and animals. There are four known ascorbate biosynthetic pathways in plants: the L-galactose, L-gulose, D-galacturonate, and -inositol routes. These pathways converge into two AsA precursors: L-galactono-1,4-lactone and L-gulono-1,4-lactone (L-GulL).
View Article and Find Full Text PDFNicotiana benthamiana was used as a model to investigate the spatial and developmental relationship between sterol synthesis rates and sterol content in plants. Stigmasterol levels were approximately twice the level in roots as that found in aerial tissues, while its progenitor sterol sitosterol was the inverse. When incorporation of radiolabeled precursors into sterols was used as measure of in vivo synthesis rates, acetate incorporation was similar across all tissue types, but approximately twofold greater in roots than any other tissue.
View Article and Find Full Text PDFVitamin C (ascorbate, AsA) is the most abundant water-soluble antioxidant in plants. Ascorbate provides the first line of defense against damaging reactive oxygen species (ROS), and helps protect plant cells from many factors that induce oxidative stress, including wounding, ozone, high salinity, and pathogen attack. Plant defenses against these stresses are also dependent upon jasmonates (JAs), a class of plant hormones that promote ROS accumulation.
View Article and Find Full Text PDFJasmonoyl-L-isoleucine (JA-Ile) is a key jasmonate signal that probably functions in all plant species. The JASMONATE RESISTANT 1 (JAR1) enzyme synthesizes JA-Ile in Arabidopsis [Arabidopsis thaliana (L.) Heynh.
View Article and Find Full Text PDFThe Arabidopsis thaliana (L.) Heynh. JASMONATE RESISTANT 1( JAR1) locus is essential for pathogen defense, but its role in wound response has not been investigated.
View Article and Find Full Text PDFJasmonate:amino acid synthetase (JAR1) is involved in the function of jasmonic acid (JA) as a plant hormone. It catalyzes the synthesis of several JA-amido conjugates, the most important of which appears to be JA-Ile. Structurally, JAR1 is a member of the firefly luciferase superfamily that comprises enzymes that adenylate various organic acids.
View Article and Find Full Text PDFSubstantial evidence indicates that amino acid conjugates of indole-3-acetic acid (IAA) function in auxin homeostasis, yet the plant enzymes involved in their biosynthesis have not been identified. We tested whether several Arabidopsis thaliana enzymes that are related to the auxin-induced soybean (Glycine max) GH3 gene product synthesize IAA-amino acid conjugates. In vitro reactions with six recombinant GH3 enzymes produced IAA conjugates with several amino acids, based on thin layer chromatography.
View Article and Find Full Text PDF