Plants produce a vast array of small molecules, called specialized metabolites, in response to various physiological and ecological stimuli. Despite the rich arsenal of techniques available, the biological roles of many plant metabolites still remain uncovered, and, in this context, several efforts have been made to unravel the functions of two indolamines, i.e., tryptamine (TAM) and serotonin (SER).

The biosynthetic pathway involving TAM and SER in plants starts with the decarboxylation of tryptophan by tryptophan decarboxylase (TDC) to produce TAM, which is, in turn, converted into SER by tryptamine 5-hydroxylase (T5H). TAM and SER have been declared as intermediates in the biosynthesis of melatonin. However, the very high values of TAM and SER in plants (μg/g of fresh weight), especially in the edible fruits and seeds of important crops, for example, tomato, suggest that they have specific biological roles in reproductive organs.

To study the biological roles of TAM and SER in Solanum lycopersicum, we previously characterized a three-member TDC gene family and a single T5H gene. Moreover, after combining gene expression levels with indolamine contents in tomato tissues and organs, we proposed a model where SlTDC1 and SlTDC2 promote TAM accumulation in fruits and in aerial vegetative organs, respectively. SlTDC3 drives TAM synthesis in roots and seeds, and SlT5H catalyzes the conversion of TAM to SER throughout the plant.

A metabolic engineering approach involving both conventional transgenesis and CRISPR/Cas9-mediated gene knockout was followed to generate tomato lines with altered TAM and SER levels. Phenotypic analysis of SlTDC1-overexpressing and knockout lines revealed notable changes in fruit size and number compared to the wild-type line. Additionally, seeds from the SlTDC1-knockout lines exhibited altered seed coat pigmentation and reduced germination rates. These observations suggest that TAM and SER may play critical roles in the reproductive development of tomato plants.

Climate change, marked by rising temperatures and fluctuating precipitation, threatens agricultural systems globally, with arid regions in Africa being particularly vulnerable. Climate change has significant implications for the biology and biochemistry of plants and crops, which impacts the allelopathic interactions between crops and weeds. Allelopathy is a potential natural solution for enhancing crop resilience and weed management. This systematic review explores the intersection of plant–crop biology, biochemistry, and allelopathy under climate change conditions, emphasizing species-specific responses and the effects of temperature and precipitation changes.
Species such as sorghum, millet, and invasive weeds like Striga respond to allelopathy when subjected to drought and heat stress, with some plants showing enhanced allelopathic activity as a defense mechanism. This study evaluates how these gene expression changes can be harnessed in agronomic practices to improve crop performance and sustainability. For example, breeding programs could integrate allelopathic traits with drought tolerance, leading to the development of plant varieties that are naturally competitive against weeds and resilient to water scarcity. Such strategies could reduce the dependence on chemical herbicides, promote sustainable agriculture, and enhance food security in arid African regions.
This systematic review compares how different crops and weeds, particularly those found in arid African environments, respond to climate-induced stress.
The paper concludes by discussing the potential benefits for African agriculture, particularly in terms of yield stability, environmental sustainability, and resource conservation. This integration of allelopathic gene expression with agronomic practices offers a promising avenue for mitigating the impacts of climate change while promoting agriculture in arid regions of Africa.

The European Union (EU) Blue Deal has dealt with the preservation of vulnerable freshwater supplies and recommended water reclamation and reuse applications. The use of biochar is a promising technique for water treatment and reclamation. From this point of view, malt dust, which is an agro-industrial by-product of the brewery industry, was used as the feedstock of biochar for the treatment of the greywater originating from a kitchen sink and a laundry rinse cycle to obtain the reclaimed water quality. This paper mainly aimed to determine the quality of reclaimed water using biochar application. Turbidity, Biological Oxygen Demand (BOD₅), Total Suspended Solid (TSS), and E. coli analyses were performed to determine the effluent quality. According to the EU Wastewater Reclamation and Reuse Legislation, Class-A-quality reclaimed water can be used for the irrigation of all kinds of agricultural crops. Otherwise, Class-B-quality reclaimed water can be used for the irrigation of above-low-ground and high-ground crops such as tomatoes, peppers, or fruit trees. At the end of treatment, the reclaimed water met the requirement of the Class B quality according to EU legislation, considering all parameters. E. coli values met both Class A and Class B qualities for each season. Only TSS in winter met the Class A quality requirements, while the others met in the range of Class B quality. Turbidity and BOD₅ met the Class B quality criteria. In the results of the overall assessment, the effluent met the Class B reclaimed water quality considering the minimum criterion requirement. This study has verified that malt dust-derived biochar is an efficient and low-cost adsorbent to obtain reclaimed water quality. The reclaimed water was used for the green area irrigation of Osmanbey Campus in Turkey.

The increasing global food demand and dwindling water resources necessitate a paradigm shift towards water-efficient agricultural technologies. This study explores the integration of drip irrigation and hydroponics to optimize water use efficiency in precision agriculture. Both techniques offer viable alternatives for sustaining agricultural yields while conserving water. This research employs a comprehensive methodology that includes modeling, data analysis, and field trials. Three experimental setups were established: a control group using traditional soil-based farming, a hydroponic system, and a hybrid system combining hydroponics with drip irrigation. Each group experiences varying water regimes, enabling the quantification of water usage, crop growth, and yield. To assess the effectiveness of each system in maintaining optimal growing conditions, we employed soil moisture sensors and climate monitoring devices. The preliminary results indicate that both the hydroponic and hybrid systems utilize significantly less water than conventional soil-based methods. Additionally, these systems demonstrate higher crop production and accelerated plant growth, attributed to enhanced nutrient uptake and improved root development. Economic analyses and life-cycle assessments were conducted to evaluate the cost-effectiveness and environmental impacts of the proposed systems. The initial findings suggest that while the upfront investment is higher, the long-term benefits of reduced water consumption and improved crop yields render these systems both environmentally and financially sustainable. This study provides practical insights into the combination of drip irrigation and hydroponics in precision agriculture, offering a roadmap for increasing crop productivity and water use efficiency. The implications of these findings are particularly relevant for sustainable farming practices in regions facing water scarcity and rising agricultural demand.

Plant breeding has significantly increased the yield, quality, and disease resistance of crops. Advances in genomic resources have revolutionized this field, allowing for the precise identification of genes and the application of marker-assisted selection (MAS) through molecular breeding techniques. These advancements are supported by various powerful tools, including genomic sequences, molecular markers, genetic transformation, and genome editing methods, all utilized to improve crops such as tomatoes. Tomatoes represent a major global agriculture commodity, with an estimated value of USD 1.4 billion. In North Carolina alone, tomato cultivation contributes approximately USD 35 million annually, spanning 3,200 acres of cultivated land. This presentation will focus on the genomic and biotechnological resources employed in crop improvement, using North Carolina (NC), USA, as a representative case study. The NC State Tomato Breeding Program enhances tomato varieties by improving their disease resistance and fruit quality. Substantial progress has been made by integrating conventional and molecular breeding approaches. However, new challenges, particularly from evolving pests and diseases, require ongoing research and development efforts. Fruit quality is a multifaceted trait assessed based on various parameters such as shape, size, smoothness, lycopene content, and flavor. The NC State Tomato Breeding Program strives to optimize these attributes to meet market demands and consumer preferences. The program's efforts include the development of new tomato varieties that exhibit superior qualities in these areas. This presentation will outline the ongoing breeding initiatives aimed at addressing the challenges that are faced by tomato cultivation. It will delve into the methodologies employed, encompassing conventional breeding techniques and cutting-edge molecular approaches. Through this comprehensive overview, the audience will gain a deeper understanding of the critical role that genomic and biotechnological resources play in modern crop improvement efforts.

Neglected and underutilized species (NUS) offer a promising avenue to tackle challenges posed by climate change while providing biofunctional compounds beneficial for human health. These plants, either never fully domesticated or underrepresented within mainstream agriculture, hold vast potential to diversify food systems and enhance agricultural resilience.

This work highlights examples of NUS, comprising traditional varieties, studied under projects HortNext and SOLECO for their valorization. Investigations included morphological, genetic, and chemical characterization, as well as assessing tolerance to environmental stressors like salinity. Efforts also integrated collaborations with farmers and consumers to ensure the practical applicability and market acceptance of these crops. The results in these projects revealed that NUS demonstrates robust tolerance to abiotic stressors, including drought and salinity. Furthermore, these plants were rich in biofunctional compounds like glucosinolates, phenols, and antioxidants. For example, specific studies on COMAV’s cauliflower collection identified genotypes with unique glucosinolate profiles and partitioning beneficial for pest resistance. A weed like wall rocket (Diplotaxis tenuifolia) showcased high phenol levels with a spicy flavour, supporting its potential domestication and use for salads. The consumer acceptance of different NUS has been also tested with consumer panels which affirmed positive perceptions on traditional varieties.

NUS and landraces are invaluable for developing resilient agricultural systems and promoting dietary diversity. Despite their potential, challenges remain, including germplasm recovery, understanding functional properties, integration into modern agriculture, and market promotion. Addressing these hurdles through collaborative research, farmer involvement, and consumer education can unlock the full potential of these crops. Projects like HortNext and SOLECO exemplify the strides being made to achieve sustainable, resilient, and healthy horticulture in a changing climate.