SlMYC2 interacted with the SlTOR promoter and mediated JA signaling to regulate growth and fruit quality in tomato

The Mitochondrial Blueprint: Unlocking Secondary Metabolite Production

Mitochondrial metabolism plays a pivotal role in regulating the synthesis of secondary metabolites, which are crucial for the survival and adaptation of organisms. These metabolites are synthesized during specific growth stages or in response to environmental stress, reflecting the organism's ability to adapt to changing conditions. Mitochondria, while primarily known for their role in energy production, directly regulate secondary metabolite biosynthesis by providing essential precursor molecules, energy, and reducing equivalents necessary for metabolic reactions. Furthermore, they indirectly influence secondary metabolism through intricate signaling pathways, including reactive oxygen species (ROS), metabolites, and redox signaling, which modulate various metabolic processes. This review explores recent advances in understanding the molecular mechanisms governing mitochondrial metabolism and their regulatory roles in secondary metabolite biosynthesis, which highlights the involvement of transcription factors, small RNAs, and post-translational mitochondrial modifications in shaping these processes. By integrating current insights, it aims to inspire future research into mitochondrial regulatory mechanisms in Arabidopsis thaliana, Solanum tuberosum, Nicotiana tabacum, and others that may enhance their secondary metabolite production. A deeper understanding of the roles of mitochondria in secondary metabolism could contribute to the development of new approaches in biotechnology applications.

Hydrogen peroxide modulates the expression of the target of rapamycin (TOR) and cell division in Arabidopsis thaliana

Hydrogen peroxide (H2O2) is naturally produced by plant cells during normal development and serves as a messenger that regulates cell metabolism. Despite its importance, the relationship between hydrogen peroxide and the target of rapamycin (TOR) pathway, as well as its impact on cell division, has been poorly analyzed. In this study, we explore the interaction of H2O2 with TOR, a serine/threonine protein kinase that plays a central role in controlling cell growth, size, and metabolism in Arabidopsis thaliana. By applying two concentrations of H2O2 exogenously (0.5 and 1 mM), we could correlate developmental traits, such as primary root growth, lateral root formation, and fresh weight, with the expression of the cell cycle gene CYCB1;1, as well as TOR expression. When assessing the expression of the ribosome biogenesis-related gene RPS27B, an increase of 94.34% was noted following exposure to 1 mM H2O2 treatment. This increase was suppressed by the TOR inhibitor torin 2. The elimination of H2O2 accumulation with ascorbic acid (AA) resulted in decreased cell division as well as TOR expression. The potential molecular mechanisms associated with the effects of H2O2 on the cell cycle and TOR expression in roots are discussed in the context of the results.

Advances in functional studies of plant MYC transcription factors

Myelocytomatosis (MYC) transcription factors (TFs) belong to the basic helix-loop-helix (bHLH) family in plants and play a central role in governing a wide range of physiological processes. These processes encompass plant growth, development, adaptation to biotic and abiotic stresses, as well as secondary metabolism. In recent decades, significant strides have been made in comprehending the multifaceted regulatory functions of MYCs. This advancement has been achieved through the cloning of MYCs and the characterization of plants with MYC deficiencies or overexpression, employing comprehensive genome-wide 'omics' and protein-protein interaction technologies. MYCs act as pivotal components in integrating signals from various phytohormones' transcriptional regulators to orchestrate genome-wide transcriptional reprogramming. In this review, we have compiled current research on the role of MYCs as molecular switches that modulate signal transduction pathways mediated by phytohormones and phytochromes. This comprehensive overview allows us to address lingering questions regarding the interplay of signals in response to environmental cues and developmental shift. It also sheds light on the potential implications for enhancing plant resistance to diverse biotic and abiotic stresses through genetic improvements achieved by plant breeding and synthetic biology efforts.

Recent Advances in Studying the Regulation of Fruit Ripening in Tomato Using Genetic Engineering Approaches

Tomato (Solanum lycopersicum L.) is one of the most commercially essential vegetable crops cultivated worldwide. In addition to the nutritional value, tomato is an excellent model for studying climacteric fruits' ripening processes. Despite this, the available natural pool of genes that allows expanding phenotypic diversity is limited, and the difficulties of crossing using classical selection methods when stacking traits increase proportionally with each additional feature. Modern methods of the genetic engineering of tomatoes have extensive potential applications, such as enhancing the expression of existing gene(s), integrating artificial and heterologous gene(s), pointing changes in target gene sequences while keeping allelic combinations characteristic of successful commercial varieties, and many others. However, it is necessary to understand the fundamental principles of the gene molecular regulation involved in tomato fruit ripening for its successful use in creating new varieties. Although the candidate genes mediate ripening have been identified, a complete picture of their relationship has yet to be formed. This review summarizes the latest (2017-2023) achievements related to studying the ripening processes of tomato fruits. This work attempts to systematize the results of various research articles and display the interaction pattern of genes regulating the process of tomato fruit ripening.

Integrated multi-omic analysis reveals the cytokinin and sucrose metabolism-mediated regulation of flavone glycoside biosynthesis by MeJA exposure in Ficus pandurata Hance

Ficus pandurata Hance (FPH) holds a rich history as a traditional Chinese botanical remedy, utilized both as a culinary condiment and a medicinal intervention for diverse ailments. This study focuses on enhancing FPH's therapeutic potential by subjecting it to exogenous methyl jasmonate (MeJA) treatment, a strategy aimed at elevating the levels of active constituents to align with clinical and commercial requirements. Employing metabolomics, the impact of MeJA treatment on the lipid and flavonoid profiles of FPH leaves was investigated, revealing a marked increase in flavone glycosides, a subset of flavonoids. Investigation into the regulatory mechanism governing flavone glycoside biosynthesis uncovered elevated expression of structural genes associated with flavonoid production in response to MeJA exposure. Global endogenous hormone analysis pinpointed the selective activation of JA and cytokinin biosynthesis following MeJA treatment. Through a comprehensive integration of transcriptomic and metabolomic data, the cooperative stimulation of glucosyltransferase activity, alongside the JA and cytokinin signaling pathways, orchestrated by MeJA were explored. Furthermore, genes linked to sucrose metabolism exhibited heightened expression, concomitant with a noteworthy surge in antioxidant activity subsequent to MeJA treatment. These findings validate the augmentation of FPH leaf antioxidant capacity through MeJA intervention, while also offering profound insights into the regulatory role of MeJA in flavone glycoside biosynthesis, mediated by the interplay between cytokinin and sucrose metabolism pathways.

MYC2: A Master Switch for Plant Physiological Processes and Specialized Metabolite Synthesis

The jasmonic acid (JA) signaling pathway plays important roles in plant defenses, development, and the synthesis of specialized metabolites synthesis. Transcription factor MYC2 is a major regulator of the JA signaling pathway and is involved in the regulation of plant physiological processes and specialized metabolite synthesis. Based on our understanding of the mechanism underlying the regulation of specialized metabolite synthesis in plants by the transcription factor MYC2, the use of synthetic biology approaches to design MYC2-driven chassis cells for the synthesis of specialized metabolites with high medicinal value, such as paclitaxel, vincristine, and artemisinin, seems to be a promising strategy. In this review, the regulatory role of MYC2 in JA signal transduction of plants to biotic and abiotic stresses, plant growth, development and specialized metabolite synthesis is described in detail, which will provide valuable reference for the use of MYC2 molecular switches to regulate plant specialized metabolite biosynthesis.