The application of salicylic acid minimizes the deleterious effects of water deficit in tomato through metabolic and ABA adjustments.

Tomato is an important horticultural crop that is adversely affected by water deficit. However, the deleterious effects of water deficiency can be mitigated through the application of salicylic acid (SA). While SA works as a critical signaling molecule in stress mitigation, abscisic acid (ABA) is another key phytohormone involved in regulation plant responses to abiotic stress.

SlBBX26 regulates vegetative growth, flowering and fruit development through the modulation of SlPIF4.

The BBX family of transcription factors regulate several physiological processes during plant vegetative and reproductive development, bridging light signaling to hormones metabolism. Here, we do an in-depth functional characterization of the tomato SlBBX26 (Solyc10g006750) gene by generating and phenotyping CRISPR/Cas9-mediated genome-edited and RNAi-mediated knockdown lines. We demonstrate that SlBBX26 regulates the negative factor of light signaling, PHYTOCHROME INTERACTING PROTEIN 4 (PIF4), which in turn modulates vegetative growth and flowering by controlling gibberellins (GAs) biosynthetic genes expression and signaling, respectively.

Reassessing Drought Tolerance in Citrus Tetraploid Rootstocks: Myth or Reality?

Polyploidy, particularly tetraploidy, has emerged as a promising tool in citrus rootstock breeding due to its potential to enhance drought tolerance. This review examines the role of tetraploid rootstocks in drought resilience, focusing on molecular and physiological adaptations observed in controlled environments and field conditions. Tetraploids display traits such as increased abscisic acid (ABA) production, antioxidant defenses, and osmotic adjustments.

Functional interactions among H2O2, NO, H2S, and melatonin in the physiology, metabolism, and quality of horticultural Solanaceae.

Cellular signaling is a key component of both intra- and intercellular communication, playing a crucial role in the development of higher plants as well as in their responses to environmental conditions of both abiotic and biotic origin. In recent decades, molecules such as hydrogen peroxide (H2O2), nitric oxide (NO), hydrogen sulfide (H2S), and melatonin have gained significant relevance in plant physiology and biochemistry due to their signaling functions and their interactions, forming a comprehensive cellular communication network. The Solanaceae family includes a group of horticultural crops of great global importance, for example tomatoes, eggplants, and peppers, which are of major agroeconomic significance due to their widespread cultivation and consumption.

Revisiting Citrus Rootstocks Polyploidy as a Means to Improve Drought Resilience: Sometimes Less Is More.

Polyploid varieties have been suggested as an alternative approach to promote drought tolerance in citrus crops. In this study, we compared the responses of diploid and tetraploid Sunki 'Tropical' rootstocks to water deficit when grafted onto 'Valencia' sweet orange trees and subjected to water withholding in isolation or competition experiments under potted conditions. Our results revealed that, when grown in isolation, tetraploid rootstocks took longer to show drought symptoms, but this advantage disappeared when grown in competition under the same soil moisture conditions.

Carotenoids and Tocopherol Profiling in Fleshy Fruits.

Carotenoids and tocopherols are among the most powerful lipophilic antioxidants accumulated in fruit and vegetable crops. This chapter describes a method for the separation and quantification of carotenoids/chlorophylls and tocopherols based on microextraction followed by reverse- and normal-phase HPLC, respectively. Using this method, high-throughput, accurate analysis of these compounds can be performed in leaf and fruit samples.

A tomato B-box protein regulates plant development and fruit quality through the interaction with PIF4, HY5, and RIN transcription factors.

During the last decade, knowledge about BBX proteins has greatly increased. Genome-wide studies identified the BBX gene family in several ornamental, industry, and food crops; however, reports regarding the role of these genes as regulators of agronomically important traits are scarce. Here, by phenotyping a knockout mutant, we performed a comprehensive functional characterization of the tomato locus Solyc12g089240, hereafter called SlBBX20.

Tomato miR156-targeted SlSBP15 represses shoot branching by modulating hormone dynamics and interacting with GOBLET and BRANCHED1b.

The miRNA156 (miR156)/SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL/SBP) regulatory hub is highly conserved among phylogenetically distinct species, but how it interconnects multiple pathways to converge to common integrators controlling shoot architecture is still unclear. Here, we demonstrated that the miR156/SlSBP15 node modulates tomato shoot branching by connecting multiple phytohormones with classical genetic pathways regulating both axillary bud development and outgrowth. miR156-overexpressing plants (156-OE) displayed high shoot branching, whereas plants overexpressing a miR156-resistant SlSBP15 allele (rSBP15) showed arrested shoot branching.

Loss of S-nitrosoglutathione reductase disturbs phytohormone homeostasis and regulates shoot side branching and fruit growth in tomato.

S-Nitrosoglutathione plays a central role in nitric oxide (NO) homeostasis, and S-nitrosoglutathione reductase (GSNOR) regulates the cellular levels of S-nitrosoglutathione across kingdoms. Here, we investigated the role of endogenous NO in shaping shoot architecture and controlling fruit set and growth in tomato (Solanum lycopersicum). SlGSNOR silencing promoted shoot side branching and led to reduced fruit size, negatively impacting fruit yield.

CRYPTOCHROME 1a-mediated blue light perception regulates tomato seed germination via changes in hormonal balance and endosperm-degrading hydrolase dynamics.

Blue light exposure delays tomato seed germination by decreasing endosperm-degrading hydrolase activities, a process regulated by CRY1a-dependent signaling and the hormonal balance between ABA and GA. The germination of tomato seeds (Solanum lycopersicum L.) is tightly controlled by an internal hormonal balance, which is also influenced by environmental factors such as light.

Fruit Physiology through Signaling Processes: Latest Advances and Future Challenges.

Fruits are unique to flowering plants and confer a selective advantage to these species by facilitating seed maturation and dispersal [...

Phytol recycling: essential, yet not limiting for tomato fruit tocopherol accumulation under normal growing conditions.

Tocopherols are potent membrane-bound antioxidant molecules that are paramount for plant physiology and also important for human health. In the past years, chlorophyll catabolism was identified as the primary source of phytyl diphosphate for tocopherol synthesis by the action of two enzymes, PHYTOL KINASE (VTE5) and PHYTHYL PHOSPHATE KINASE (VTE6) that are able to recycle the chlorophyll-derived phytol. While VTE5 and VTE6 were proven essential for tocopherol metabolism in tomato fruits, it remains unknown whether they are rate-limiting steps in this pathway.

Proteomic Analysis of -Nitrosation Sites During Somatic Embryogenesis in Brazilian Pine, (Bertol.) Kuntze.

Cysteine -nitrosation is a redox-based post-translational modification that mediates nitric oxide (NO) regulation of various aspects of plant growth, development and stress responses. Despite its importance, studies exploring protein signaling pathways that are regulated by -nitrosation during somatic embryogenesis have not been performed. In the present study, endogenous cysteine -nitrosation site and -nitrosated proteins were identified by iodo-TMT labeling during somatic embryogenesis in Brazilian pine, an endangered native conifer of South America.

SlBBX28 positively regulates plant growth and flower number in an auxin-mediated manner in tomato.

SlBBX28 is a positive regulator of auxin metabolism and signaling, affecting plant growth and flower number in tomato B-box domain-containing proteins (BBXs) comprise a family of transcription factors that regulate several processes, such as photomorphogenesis, flowering, and stress responses. For this reason, attention is being directed toward the functional characterization of these proteins, although knowledge in species other than Arabidopsis thaliana remains scarce. Particularly in the tomato, Solanum lycopersicum, only three out of 31 SlBBX proteins have been functionally characterized to date.

Drought tolerance memory transmission by citrus buds.

Plants face recurrent drought events, and previous stresses can influence their responses to subsequent stress episodes. Studies on drought stress memory are recent in citriculture, although they show promise as a tool for crop improvement. Here, we investigated whether stress memory mechanisms can be detected in citrus plants grafted with buds from plants subjected to recurrent water deficit.

Auxin-driven ecophysiological diversification of leaves in domesticated tomato.

Heterobaric leaves have bundle sheath extensions (BSEs) that compartmentalize the parenchyma, whereas homobaric leaves do not. The presence of BSEs affects leaf hydraulics and photosynthetic rate. The tomato (Solanum lycopersicum) obscuravenosa (obv) mutant lacks BSEs.

Increased branching independent of strigolactone in cytokinin oxidase 2-overexpressing tomato is mediated by reduced auxin transport.

Tomato production is influenced by shoot branching, which is controlled by different hormones. Here we produced tomato plants overexpressing the cytokinin-deactivating gene CYTOKININ OXYDASE 2 (CKX2). CKX2-overexpressing (CKX2-OE) plants showed an excessive growth of axillary shoots, the opposite phenotype expected for plants with reduced cytokinin content, as evidenced by LC-MS analysis and ARR5-GUS staining.

Ethylene and Auxin: Hormonal Regulation of Volatile Compound Production During Tomato ( L.) Fruit Ripening.

As the auxin-ethylene interaction in climacteric fruit ripening has been highlighted, the hormonal regulation of aroma changes in climacteric fruits requires clarification. The influence of both phytohormones on the volatile organic compound (VOC) metabolism was evaluated during tomato ( L.) fruit ripening.

Moniliophthora perniciosa, the causal agent of witches' broom disease of cacao, interferes with cytokinin metabolism during infection of Micro-Tom tomato and promotes symptom development.

Moniliophthora perniciosa causes witches' broom disease of cacao and inflicts symptoms suggestive of hormonal imbalance. We investigated whether infection of the tomato (Solanum lycopersicum) model system Micro-Tom (MT) by the Solanaceae (S)-biotype of Moniliophthora perniciosa, which causes stem swelling and hypertrophic growth of axillary shoots, results from changes in host cytokinin metabolism. Inoculation of an MT-transgenic line that overexpresses the Arabidopsis CYTOKININ OXIDASE-2 gene (35S::AtCKX2) resulted in a reduction in disease incidence and stem diameter.

Developing Portulaca oleracea as a model system for functional genomics analysis of C/CAM photosynthesis.

Previously regarded as an intriguing photosynthetic curiosity, the occurrence of C4 and Crassulacean acid metabolism (CAM) photosynthesis within a single organism has recently emerged as a source of information for future biotechnological use. Among C4/CAM facultative species, Portulaca oleracea L. has been used as a model for biochemical and gene expression analysis of C4/CAM under field and laboratory conditions.

The light and dark sides of nitric oxide: multifaceted roles of nitric oxide in plant responses to light.

Light drives photosynthesis and informs plants about their surroundings. Regarded as a multifunctional signaling molecule in plants, nitric oxide (NO) has been repeatedly demonstrated to interact with light signaling cascades to control plant growth, development and metabolism. During early plant development, light-triggered NO accumulation counteracts negative regulators of photomorphogenesis and modulates the abundance of, and sensitivity to, plant hormones to promote seed germination and de-etiolation.

Multifaceted roles of nitric oxide in tomato fruit ripening: NO-induced metabolic rewiring and consequences for fruit quality traits.

Nitric oxide (NO) has been implicated as part of the ripening regulatory network in fleshy fruits. However, very little is known about the simultaneous action of NO on the network of regulatory events and metabolic reactions behind ripening-related changes in fruit color, taste, aroma and nutritional value. Here, we performed an in-depth characterization of the concomitant changes in tomato (Solanum lycopersicum) fruit transcriptome and metabolome associated with the delayed-ripening phenotype caused by NO supplementation at the pre-climacteric stage.