Biofortification: Future Challenges for a Newly Emerging Technology to Improve Nutrition Security Sustainably.

Biofortification was coined as a term to define a plant breeding strategy to increase the micronutrient content of staple food crops to reduce the burden of micronutrient deficiencies in low- and middle-income countries. In 2003, the HarvestPlus program, based in the centers comprising the Consultative Group on International Agricultural Research, was initiated to implement the biofortification strategy. This article discusses what has been achieved, what has been learned, and the key challenges to embed biofortification in food systems and to expand its impact.

Cytokinins regulate spatially specific ethylene production to control root growth in Arabidopsis.

Two principal growth regulators, cytokinins and ethylene, are known to interact in the regulation of plant growth. However, information about the underlying molecular mechanism and positional specificity of cytokinin/ethylene crosstalk in the control of root growth is scarce. We have identified the spatial specificity of cytokinin-regulated root elongation and root apical meristem (RAM) size, both of which we demonstrate to be dependent on ethylene biosynthesis.

Arinole, a novel auxin-stimulating benzoxazole, affects root growth and promotes adventitious root formation.

The triple response phenotype is characteristic for seedlings treated with the phytohormone ethylene or its direct precursor 1-aminocyclopropane-carboxylic acid, and is often employed to find novel chemical tools to probe ethylene responses. We identified a benzoxazole-urea derivative (B2) partially mimicking ethylene effects in a triple response bioassay. A phenotypic analysis demonstrated that B2 and its closest analogue arinole (ARI) induced phenotypic responses reminiscent of seedlings with elevated levels of auxin, including impaired hook development and inhibition of seedling growth.

OsTH1 is a key player in thiamin biosynthesis in rice.

Thiamin is a vital nutrient that acts as a cofactor for several enzymes primarily localized in the mitochondria. These thiamin-dependent enzymes are involved in energy metabolism, nucleic acid biosynthesis, and antioxidant machinery. The enzyme HMP-P kinase/thiamin monophosphate synthase (TH1) holds a key position in thiamin biosynthesis, being responsible for the phosphorylation of HMP-P into HMP-PP and for the condensation of HMP-PP and HET-P to form TMP.

A UPLC-MS/MS method for quantification of metabolites in the ethylene biosynthesis pathway and its biological validation in Arabidopsis.

The plant hormone ethylene is of vital importance in the regulation of plant development and stress responses. Recent studies revealed that 1-aminocyclopropane-1-carboxylic acid (ACC) plays a role beyond its function as an ethylene precursor. However, the absence of reliable methods to quantify ACC and its conjugates malonyl-ACC (MACC), glutamyl-ACC (GACC), and jasmonyl-ACC (JA-ACC) hinders related research.

Phytohormone profiling in an evolutionary framework.

The genomes of charophyte green algae, close relatives of land plants, typically do not show signs of developmental regulation by phytohormones. However, scattered reports of endogenous phytohormone production in these organisms exist. We performed a comprehensive analysis of multiple phytohormones in Viridiplantae, focusing mainly on charophytes.

'From metabolism to metabolism': holistic considerations on B-vitamin interactions, biofortification, and deficiencies.

In the post-Green Revolution era, disparities in dietary access, rising obesity rates, demographic shifts, adoption of plant-based diets, and the impact of climate change collectively contribute to a progressive decline in dietary nutritional value, exacerbating B vitamin deficiencies across both low- and high-income countries. While the prevailing focus of biofortification has been on three micronutrients - provitamin A, iron, and zinc - utilizing conventional breeding, it is imperative to diversify biofortification strategies to combat micronutrient malnutrition. Metabolic engineering, facilitated by biotechnological tools, presents a promising avenue, contingent upon advances in fundamental knowledge, technological innovation, regulatory updates, and sustained public funding.

Mathematical kinetic modelling followed by in vitro and in vivo assays reveal the bifunctional rice GTPCHII/DHBPS enzymes and demonstrate the key roles of OsRibA proteins in the vitamin B2 pathway.

Background: Riboflavin is the precursor of several cofactors essential for normal physical and cognitive development, but only plants and some microorganisms can produce it. Humans thus rely on their dietary intake, which at a global level is mainly constituted by cereals (> 50%). Understanding the riboflavin biosynthesis players is key for advancing our knowledge on this essential pathway and can hold promise for biofortification strategies in major crop species.

A protocol for a turbidimetric assay using a Saccharomyces cerevisiae thiamin biosynthesis mutant to estimate total vitamin B content in plant tissue samples.

Background: Understanding thiamin (thiamine; vitamin B) metabolism in plants is crucial, as it impacts plant nutritional value as well as stress tolerance. Studies aimed at elucidating novel aspects of thiamin in plants rely on adequate assessment of thiamin content. Mass spectrometry-based methods provide reliable quantification of thiamin as well as closely related biomolecules.

Ectopic Expression of Distinct PLC Genes Identifies 'Compactness' as a Possible Architectural Shoot Strategy to Cope with Drought Stress.

Phospholipase C (PLC) has been implicated in several stress responses, including drought. Overexpression (OE) of PLC has been shown to improve drought tolerance in various plant species. Arabidopsis contains nine PLC genes, which are subdivided into four clades.

Belgian dietitians' knowledge, perceptions and willingness-to-recommend of genetically modified food and organisms.

Background: Dietitians play a critical role in the public's relationship with food and are often overlooked as an important stakeholder group in the general debate about sustainable food. Genetically modified organisms (GMOs) are one type of modern food source that could contribute to a more sustainable food system. This case study is the first to examine the knowledge, perception and willingness-to-recommend (WTR) genetically modified (GM) foods by dietitians in Europe.

The role of orphan crops in the transition to nutritional quality-oriented crop improvement.

Micronutrient malnutrition is a persisting problem threatening global human health. Biofortification via metabolic engineering has been proposed as a cost-effective and short-term means to alleviate this burden. There has been a recent rise in the recognition of potential that underutilized, orphan crops can hold in decreasing malnutrition concerns.

UV-B responses in the spotlight: Dynamic photoreceptor interplay and cell-type specificity.

Plants are constantly exposed to a multitude of external signals, including light. The information contained within the full spectrum of light is perceived by a battery of photoreceptors, each with specific and shared signalling outputs. Recently, it has become clear that UV-B radiation is a vital component of the electromagnetic spectrum, guiding growth and being crucial for plant fitness.

Plants can talk: a new era in plant acoustics.

Plants release chemical signals to interact with their environment when exposed to stress. Khait and colleagues unveiled that plants 'verbalize' stress by emitting airborne sounds. These can train machine learning models to identify plant stressors.

Plants 'cry' for help through acoustic signals.

Plants perceive sounds, while responses to these sounds were already known. A breakthrough is the discovery by Khait et al. that stressed plants emit various informative ultrasonic sound signals, which can be categorized according to plant species, stress type, and stress severity.

Sound perception in plants: from ecological significance to molecular understanding.

In addition to positive effects on plant growth and resilience, sound alerts plants of potential danger and aids in defense. Sound guides plants towards essential resources, like water, through phonotropic root growth. Sound also facilitates mutualistic interactions such as buzz pollination.

Public acceptance and stakeholder views of gene edited foods: a global overview.

The increasing popularity of gene editing in plants has prompted research on stakeholder views. Gene edited foods are often more accepted than genetically modified foods, though differences occur within target groups, regions, and products. Nevertheless, marketing challenges related to a lack of familiarity with the technology, labeling, and risk perception remain.

Quantitative mapping of mercury and selenium in mushroom fruit bodies with laser ablation-inductively coupled plasma-mass spectrometry.

This work describes the development of a novel method for quantitative mapping of Hg and Se in mushroom fruit body tissues with laser ablation coupled to inductively coupled plasma-mass spectrometry (LA-ICP-MS). Different parameters of the protocol for preparation of the standards used for quantification via external calibration were assessed, e.g.

Foliar and Root Comparative Metabolomics and Phenolic Profiling of Micro-Tom Tomato ( L.) Plants Associated with a Gene Expression Analysis in Response to Short Daily UV Treatments.

Tomato ( L.) is globally recognised as a high-value crop both for commercial profit and nutritional benefits. In contrast to the extensive data regarding the changes in the metabolism of tomato fruit exposed to UV radiation, less is known about the foliar and root metabolome.

A novel panel of yeast assays for the assessment of thiamin and its biosynthetic intermediates in plant tissues.

Thiamin (or thiamine), known as vitamin B1, represents an indispensable component of human diets, being pivotal in energy metabolism. Thiamin research depends on adequate vitamin quantification in plant tissues. A recently developed quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is able to assess the level of thiamin, its phosphorylated entities and its biosynthetic intermediates in the model plant Arabidopsis thaliana, as well as in rice.

Ethylene signaling in salt-stressed Arabidopsis thaliana ein2-1 and ctr1-1 mutants - A dissection of molecular mechanisms involved in acclimation.

To pinpoint ethylene-mediated molecular mechanisms involved in the adaptive response to salt stress we conducted a comparative study of Arabidopsis thaliana wild type (Col-0), ethylene insensitive (ein2-1), and constitutive signaling (ctr1-1) mutant plants. Reduced germination and survival rates were observed in ein2-1 plants at increasing NaCl concentrations. By contrast, ctr1-1 mutation conferred salt stress tolerance during early vegetative development, corroborating earlier studies.

The 5-formyl-tetrahydrofolate proteome links folates with C/N metabolism and reveals feedback regulation of folate biosynthesis.

Folates are indispensable for plant development, but their molecular mode of action remains elusive. We synthesized a probe, "5-F-THF-Dayne," comprising 5-formyl-tetrahydrofolate (THF) coupled to a photoaffinity tag. Exploiting this probe in an affinity proteomics study in Arabidopsis thaliana, we retrieved 51 hits.

Cryptochromes are the dominant photoreceptors mediating heliotropic responses of Arabidopsis inflorescences.

Inflorescence movements in response to natural gradients of sunlight are frequently observed in the plant kingdom and are suggested to contribute to reproductive success. Although the physiological and molecular bases of light-mediated tropisms in vegetative organs have been thoroughly investigated, the mechanisms that control inflorescence orientation in response to light gradients under natural conditions are not well understood. In this work, we have used a combination of laboratory and field experiments to investigate light-mediated re-orientation of Arabidopsis thaliana inflorescences.