Legumes produce protein-rich seeds and have been cultivated for centuries to feed humanity and livestock. Despite their ability to fix dinitrogen, seedlings are sensitive to nitrogen availability before symbiosis establishment. In the past years, our team has been working on seedling pre-emergence (i.e. heterotrophic) growth with and without nitrogen source, using a broad panel of accessions of barrel medic (Medicago truncatula), a model legume plant. In other Legumes like pea, sulfur metabolism appears to be critical during germinative and post-germinative events. Thus, we assume sulfur nutrition may influence seedling growth properties of genotypes. The present study focuses on the genotypic variability on a selection of accessions of M. truncatula during the heterotrophic growth, under different nutrient conditions, including sulfate availability. We determined traits associated with seedling performance (seed biomass use and organ elongation) to characterize phenotypic variations in response to contrasting nitrate and sulfate conditions. The study reveals that genotype response to nitrate deficiency is influenced by sulfate availability, the genotype × nutrient conditions interaction being more or less pronounced depending on the trait. Elemental, isotopic and inorganic anion analyses of seeds and seedling organs also reveal genetic variability and highlight genotype x nutrient conditions interaction, suggesting differential N/S metabolic interactions amongst accessions.

In addition to genetics, nitrogen fertilization plays a crucial role in determining wheat quality. It influences both the final crude protein concentration and the associated protein quality in the grain. These factors are directly reflected in the baking quality of the wheat. Key aspects include the timing, rate, and specific doses of nitrogen fertilization. For instance, nitrogen application early in the growing season has a greater impact on tillering, whereas later applications more strongly influence grain filling and, consequently, protein concentration in the grain. The effects of timing and application rates are significant. Additionally, the form of nitrogen, such as nitrate-based or ammonium-based fertilization, also impacts the eventual protein quality. Storage proteins in grain develop during ear development and the grain-filling phase, during which specific prolamins are formed sequentially. Under drought stress, the development of gliadins and glutenins in the grain also adapts. This presentation will discuss results from various trials and provide an overview spanning from crop cultivation to bread quality.

Oregano (Origanum vulgare L.) is a traditional medicinal plant that is widely used for its health benefits due to its pharmacological properties, such as antimicrobial, carminative and antioxidant activities. Heat stress caused by climate change severely restricts the growth and yield of medicinal plants. Limited studies show that the application of natural biostimulants is an innovative and cost-effective alternative to synthetic fertilizers for enhancing plant growth and productivity. Also, little is known about the effect of nano-fertilizers on the growth and biochemical characteristics of medicinal plants. Thus, the current study investigated the efficacy of cancer bush (Lessertia frutescens L.) leaf extract (CLE) (2%) enriched with biosynthesized zinc oxide nanoparticles (ZnO-NPs) to improve the growth and biochemical attributes of oregano subjected to heat stress (38 ˚C for 2 hours for 6 days). The treatments used were CLE, CLE + ZnO-NPs 25, 50 and 75 mg/L folia spray and plants that were folia-sprayed with water were used as control. The randomized complete block design (RCBD) was used in this study and data were collected at 7-day intervals during the experiment. The results showed that heat stress reduced the growth and yield and the physiological and phytochemical attributes of oregano. However, the application of CLE + ZnO-NPs enhanced the growth and biochemical composition of heat-stressed plants. Both 50 and 75 mg/L CLE + ZnO-NPs treatments increased the growth and yield attributes, essential oil yield, total chlorophylls and carotenoids, ascorbic acid content, total phenolic content, antioxidant enzyme activities (catalase, ascorbate peroxidase, and superoxide dismutase activities) and reduced malondialdehyde and electrolyte leakage in oregano plants compared to other treatments. Therefore, CLE-enriched ZnO-NPs, especially at 50 and 75 mg/L concentrations, can be recommended for improving the productivity and biochemical characteristics of oregano under heat stress.

Prickles, sharp projections of plant epidermis, serve as a defense mechanism against herbivory but present significant challenges in agricultural contexts, complicating cultivation, harvesting, and postharvest processes. We used advanced tools to uncover the genetic basis of prickle formation and its convergent loss across highly divergent plant lineages. Using interspecific mapping populations of eggplant (Solanum melongena) with introgressions of prickly wild relatives, we fine-mapped the locus designated prickleless (pl) and identified a LONELY GUY (LOG) gene, which regulates cytokinin biosynthesis, as a critical factor in prickle development. High-quality genome assemblies and sequencing of diverse Solanum accessions revealed 16 independent LOG mutations associated with prickle loss in cultivated and wild species, highlighting recurrent co-option of LOG paralogs during evolution. Beyond Solanum, mutations in LOG genes were identified in distant prickly taxa, such as roses (Rosa sp.), jujube (Ziziphus jujuba), and the giant spider-flower (Tarenaya hassleriana). LOG family genes are also involved in the prickly barbs of the awns of rice (Oryza sativa) and barley (Hordeum vulgare), underscoring a conserved genetic mechanism underlying this trait. Genome editing with CRISPR-Cas9 was utilized to knock-out the LOG gene to eliminate prickles in the scarlet eggplant (S. aethiopicum), in the foraged Australian desert raisin (S. cleistogamum), and in the forest nightshade (S. prinophyllum) without pleiotropic effects, demonstrating the practical application of our findings in crop improvement. These insights pave the way for breeding prickleless varieties in economically significant plants, improving safety and efficiency in cultivation and harvesting, as well as for domesticating wild prickly foraged plants. Our work also deepens the understanding of the convergent evolution of plant innovations, such as the development of prickles.

Acanthosicyos horridus (!nara), an endemic melon species of the hyper-arid Namib Desert, inhabits sandy dunes and dry river banks in an environment shaped by the cold Benguela current. This desert experiences extreme conditions, including high temperatures, rare rainfall, and desiccating air. In such a water-limited environment, non-rainfall water inputs (NRWIs) like fog, dew, and water vapour can play crucial roles in ecosystem function, influencing how plants exploit alternative moisture sources. Fog, in particular, is a primary NRWI in the coastal Namib Desert, where !nara is common. It is hypothesised that A. horridus is adapted to utilise fog as a moisture source, sharing features with other fog-dependent organisms, such as groove-like structures and cone-shaped thorns that direct water flow. This study investigated whether !nara exploits fog by examining its direct water uptake capacity through absorption tests and time-lapse macrophotography of fluorescent water droplets on stems. Shoot water potential was also measured to assess how fog affects the plant's water status. Additionally, chlorophyll a fluorescence was used to compare photochemical efficiency on foggy versus non-foggy days, while meteorological data helped to identify other environmental stressors. The findings show that A. horridus can directly absorb fog water into its stems, and NRWIs may indirectly influence its water status through changes in environmental parameters, such as lower stomatal conductance. Despite this, !nara did not show signs of drought stress, suggesting it relies on underground water sources rather than NRWIs alone. Environmental factors like temperature stress and wind were found to significantly impact the plant's vitality, indicating that A. horridus has evolved strategies to adapt to the extreme conditions of its habitat.

With the world’s population growing at a rapid pace, ensuring global food security has emerged as the greatest concern as a result of climate change. Abiotic stresses such as water scarcity and heat stress are becoming increasingly major challenges to be addressed in order to enhance maize production.

Drip irrigation and rainfeeding (control) experiments were carried out in 2023 at the Látókép Crop Production Experimental Site of the University of Debrecen (Hungary). The purpose of this study was to evaluate the performance of the tested maize hybrid in terms of yield and the accumulation of dry matter and a few essential nutrients (N, P and K) over the growing season in both irrigated and non-irrigated conditions. For this reason, four plants were collected from each treatment at four phenological stages (V12, R1, R4 and R6) of maize growth. Plant dry matter was measured, nutrient concentrations were obtained from the dried biomass and grain yield was determined.

Based on the performed statistical analysis, the influence of irrigation was not significant regarding plant dry matter, nitrogen and potassium accumulation at different phenological stages. However, only one significant variation (p<0.01) in phosphorus uptake was identified between the treatments at V12. Conversely, drip irrigation significantly enhanced maize grain yield, producing 13.636 t/ha, i.e., 2.3 tons, surpassing the control treatment.

This study reveals the high yield potential of drip-irrigated maize and its promising solution to ensure the sustainability and resilience of the global food supply, confronting climate change.

Habibah Almalawi, Martin Edwards, Angharad Gatehouse

Faculty of Science, school of Natural and Environmental Sciences

h.a.j.almalawi2@newcastle.ac.uk; martin.edwards@newcastle.ac.uk; a.m.r.gatehouse@newcastle.ac.uk

Abstract

Global wheat production is seriously threatened by salinity stress, especially in irrigated and desert areas where crop yield is hampered by salt buildup in the soil. Utilising comparative transcriptome analysis on two genetically diverse wheat genotypes- a salt-tolerant and a salt-sensitive type- both treated with glycine betaine (GB), the goal of this work is to discover important genes and pathways involved in the salt stress tolerance of wheat (Triticum aestivum L.). Due to its osmoprotective qualities, glycine betaine is known to increase plant resistance to abiotic stressors like salt. Gene expression in wheat genotypes exposed to four treatment combinations control, salt stress, glycine betaine therapy, and the combination of both stressors was analysed using RNA sequencing. The research found thousands of differentially expressed genes (DEGs) between the salt-tolerant and sensitive genotypes, underlining important pathways associated with oxidative stress, ion transport, and osmotic adjustment. Treatment with glycine betaine changed the expression of genes that respond to stress, especially when exposed to salt stress, which enhanced the mechanisms for stress adaption. Important biological processes that are essential for stress tolerance were found using GO (Gene Ontology) enrichment analysis. These processes include cell wall metabolism, fatty acid production, and cytoskeletal dynamics. These results give molecular insights into the mechanisms by which glycine betaine increases wheat resilience to salinity, potentially serving as targets for agronomic and genetic approaches aimed at enhancing wheat performance in areas impacted by salt.

Starch is a major component of many plant-based foods, accounting for about 30-60% of total calorie intake in the diet of most cultures. It is also the major component of the most common cereal crops, such as rice, wheat, and maize. Starch is synthesized in plastids by the orchestration of several enzymes and starch-binding proteins, which shapes polyglucan chains into complex starch granules. We have studied how this orchestration occurs by using several new breeding techniques to monitor the localization and actions of the individual enzymes and factors in starch biosynthesis, such as starch synthases, glucan kinases, starch-binding proteins, and starch-branching enzymes. With insights into the role of the individual components of starch biosynthesis, it is possible to create tailor-made starch types for new functionalities. As an example, we have created starches with an exceptionally high degree of resistance towards amylolysis, by targeting selected enzymes specifically with precision breeding. Acute clinical trials have been conducted to demonstrate how crops created with such techniques can be used to make tailor-made foods with reduced postprandial glucose response in humans with and without type 2 diabetes (T2D).
Our work demonstrates how new breeding technology can be used for the precision breeding of healthier starches, which has profound perspectives for improving the quality of plant-based foods with potential in the prevention and management of T2D.

Valsa canker (VC), caused by the fungus Valsa mali, represents a significant threat to Malus plants, including both domestic apple and crabapple varieties. The identification of genes that confer resistance or susceptibility is a pivotal step in the breeding of new cultivars and the sustainable development of Malus. In this study, we present chromosome-level and near-gapless genome assemblies of two ornamental crabapple cultivars, M. ‘Prairifire’ and M. ‘Hopa’, which exhibit contrasting resistance and susceptibility to VC. Through transcriptomic analysis and quantitative real-time PCR (qRT-PCR) validation, we identified eight genes that are up-regulated during infection of M. ‘Prairifire’ by V. mali. These genes are involved in encoding various proteins, including a Yippee-like protein, secoisolariciresinol dehydrogenase, a valine-glutamine (VQ) motif-containing protein, a 23 kDa jasmonate-induced protein, a kinase domain-containing protein, a Tobacco Mosaic Virus (TMV) resistance protein, a calmodulin-related protein, and a detoxification protein. The results provide valuable genomic resources for a comprehensive investigation into the genetic basis of resistance to VC and provide a basis for the future molecular breeding of Malus.

The growing interest in sustainable extraction methods for bioactive compounds has spurred advancements in green technologies [1-2]. This study evaluates and compares two such techniques, Pressurized Liquid Extraction (PLE) and Ultrasound-Assisted Extraction (UAE), for recovering anthocyanins from purple corn using an ethanol–water (1:1) mixture with 2% o-phosphoric acid. The analytical determination employed HPLC-UV with a Kinetex C18 core–shell column, ensuring precise quantification. Optimization of the UAE was conducted through a 3441 asymmetrical design to assess variables like the amplitude, time, temperature, sample size, and pulsation cycles. At the same time, the PLE conditions were fine-tuned using a Doehlert response surface methodology.

The optimal conditions for UAE were 20 minutes at 25°C and 64 W, with pulsation cycles of 40 s ON/OFF at 20 kHz. In contrast, PLE achieved peak efficiency with a single static cycle of 3 minutes at 95°C and 1500 psi. Both methods demonstrated excellent linearity (r² > 0.9992), specificity, accuracy, and precision when validated against the FDA guidelines, with PLE exhibiting a superior limit of detection (0.97 μL/mL). A comparative analysis showed similar performance metrics; however, PLE emerged as the preferred method for occurrence studies due to its faster extraction time and robust reproducibility.

This study also incorporated innovative environmental performance metrics to assess sustainability and practical applicability [3], reinforcing the value of these techniques for eco-friendly anthocyanin extraction. The findings underscore the potential for these green methods to meet the food industry's demands and facilitate research, advancing sustainable practices in bioactive compound recovery.

References:

[1] Custodio-Mendoza, J. A., et al. Molecules, 29 (2024) 1735.

[2] de Souza Mesquita, et al., Food chem., 428 (2023) 136814.

[3] Pena-Pereira, F., et al. Adv. Sample Prep., 3 (2022). 100025.