Carotenoids represent some of the most important secondary metabolites in the human diet, and tomato (Solanum lycopersicum) is a rich source of these health-promoting compounds. In this work, a novel and fruit-related regulator of pigment accumulation in tomato has been identified by artificial neural network inference analysis and its function validated in transgenic plants. A tomato fruit gene regulatory network was generated using artificial neural network inference analysis and transcription factor gene expression profiles derived from fruits sampled at various points during development and ripening. One of the transcription factor gene expression profiles with a sequence related to an Arabidopsis (Arabidopsis thaliana) ARABIDOPSIS PSEUDO RESPONSE REGULATOR2-LIKE gene (APRR2-Like) was up-regulated at the breaker stage in wild-type tomato fruits and, when overexpressed in transgenic lines, increased plastid number, area, and pigment content, enhancing the levels of chlorophyll in immature unripe fruits and carotenoids in red ripe fruits. Analysis of the transcriptome of transgenic lines overexpressing the tomato APPR2-Like gene revealed up-regulation of several ripening-related genes in the overexpression lines, providing a link between the expression of this tomato gene and the ripening process. A putative ortholog of the tomato APPR2-Like gene in sweet pepper (Capsicum annuum) was associated with pigment accumulation in fruit tissues. We conclude that the function of this gene is conserved across taxa and that it encodes a protein that has an important role in ripening.

Global food security has been significantly threatened by the Covid-19 pandemic and several prolonged challenges such as climate change, population increases, shortage of natural resources, energy crisis, and rapid urbanisation worldwide. Although numerous attempts have been made to secure resilience in the food system, many countries are suffering from hunger and malnutrition, particularly in African and some Asian countries. This review paper presents one of the sustainable farming practices – vertical farming that could play a key role in mitigating global food security in the current uncertain world. It addresses the recent development of vertical farming with advanced precision monitoring and controlling system by the Internet of Things (IoT) applications. It also provides information about the opportunities and challenges of vertical-urban agriculture and how urban agriculture meets economic, social and educational needs.

Light-emitting diodes (LEDs) have shown great potential for plant growth and development, with higher luminous efficiency and more flexible and feasible spectral control compared with other artificial lighting. The combined effects of red and blue (RB) LED with or without green (G) LED light and white LED light on lettuce ( Lactuca sativa L.) growth and physiology, including nitrate content, chlorophyll fluorescence, and phytochemical concentration before harvest, were investigated. Continuous light exposure at preharvest can effectively reduce nitrate accumulation and increase phytochemical concentrations in lettuce plants. Nitrate accumulation is dependent on the spectral composition and duration of treatment: lettuce exposed to continuous RB (with or without G) LED light with a photosynthetic photon flux ( PPF ) of 200 µmol·m ⁻² ·s ⁻¹ exhibited a remarkable decrease in nitrate content at 24 hour compared with white LED light treatment at the same PPF . In addition, RB LED light (R:B = 4:1) was more effective than white LED light at the same PPF in facilitating lettuce growth. Moreover, continuous LED light for 24 hours significantly enhanced free-radical scavenging activity and increased phenolic compound concentrations. We suggest that 24 hours continuous RB LED with G light exposure can be used to decrease nitrate content and enhance lettuce quality.