International Centre for Genetic Engineering and Biotechnology

Drought stress significantly impedes maize (Zea mays L.) productivity globally, a challenge exacerbated by climate change. This has necessitated a deeper understanding of the molecular adaptive mechanisms operating in the plants. Treatment with nitrogen (N) and phosphorus (P) before imposition of drought stress induces a protective response to drought stress and recovery in maize seedlings. The specific miRNAs and transcripts involved in this nutrient-stress interplay are not well-documented. This study integrates in-silico analysis with experimental expression profiling to unravel the complex miRNA-mediated regulatory networks in drought stressed maize seedlings (HKI-161, HKI-193-1, HQPM-1 and HQPM-7), particularly investigating the influence of N and P supplementation. Analysis of high-throughput sequencing datasets identified 136 miRNAs that showed significant differential expression during drought stress. Comprehensive in-silico prediction and analysis of their target genes revealed the miRNA-target pairs, which are involved in critical metabolic and stress response pathways, including photosynthesis, redox balance and nutrient homeostasis. Experimental validation showed consistent inverse correlation between selected miRNAs and their targets. The down-regulation of Zma-miR156l-3p and Zma-miR398b-3p highlighted a robust strategy for activating antioxidant pathways via CAT and SOD. Key miRNA–target modules such as Zma-miR399–PHO2, Zma-miR408–Chemocyanin and Zma-miR827–SPX emerged as critical nodes linking drought stress to nutrient allocation and metabolic adjustment. Importantly, N and P supplementation significantly enhanced target gene expression and stress-responsive pathways. Genotype-specific responses indicated higher drought tolerance in HKI-193-1 and lower tolerance in HKI-161. These findings underscore the synergistic role of miRNA-target interactions in fine-tuning nutrient management for enhancing drought resilience in maize. Nitrogen and phosphorus supplementation significantly modulate the miRNA-mediated regulatory networks during drought-stress. The miR399–PHO2, miR408–Chemocyanin and miR827–SPX, regulatory nodes are involved in linking drought adaptation to nutrient allocation.

The P53-destabilizing TBC1D15-NOTCH protein interaction promotes self-renewal of tumor-initiating stem-like cells (TICs); however, the mechanisms governing the regulation of this pathway have not been fully elucidated. Here, we show that TBC1D15 stabilizes NOTCH and c-JUN through blockade of E3 ligase and CDK8 recruitment to phosphodegron sequences. Chromatin immunoprecipitation (ChIP-seq) analysis was performed to determine whether TBC1D15-dependent NOTCH1 binding occurs in TICs or non-TICs. The TIC population was isolated to evaluate TBC1D15-dependent NOTCH1 stabilization mechanisms. The tumor incidence in hepatocyte-specific triple knockout (Alb::CreERT2;Tbc1d15Flox/Flox;Notch1Flox/Flox;Notch2Flox/Flox;HCV-NS5A) Transgenic (Tg) mice and wild-type mice was compared after being fed an alcohol-containing Western diet (WD) for 12 months. The NOTCH1-TBC1D15-FIS1 interaction resulted in recruitment of mitochondria to the perinuclear region. TBC1D15 bound to full-length NUMB and to NUMB isoform 5, which lacks three Ser phosphorylation sites, and relocalized NUMB5 to mitochondria. TBC1D15 binding to NOTCH1 blocked CDK8- and CDK19-mediated phosphorylation of the NOTCH1 PEST phosphodegron to block FBW7 recruitment to Thr-2512 of NOTCH1. ChIP-seq analysis revealed that TBC1D15 and NOTCH1 regulated the expression of genes involved in mitochondrial metabolism-related pathways required for the maintenance of TICs. TBC1D15 inhibited CDK8-mediated phosphorylation to stabilize NOTCH1 and protect it from degradation The NUMB-binding oncoprotein TBC1D15 rescued NOTCH1 from NUMB-mediated ubiquitin-dependent degradation and recruited NOTCH1 to the mitochondrial outer membrane for the generation and expansion of liver TICs. A NOTCH-TBC1D15 inhibitor was found to inhibit NOTCH-dependent pathways and exhibited potent therapeutic effects in PDX mouse models. This unique targeting of the NOTCH-TBC1D15 interaction not only normalized the perinuclear localization of mitochondria but also promoted potent cytotoxic effects against TICs to eradicate patient-derived xenografts through NOTCH-dependent pathways.

Salinity is one of the major abiotic stresses that induces nitro-oxidative stress, which severely diminishes plant growth, development, and survival by altering various metabolic pathways. Phytoglobin (Pgb) is a nitric oxide (NO) scavenger that plays an important role in various stresses. However, the role of differential levels of phytoglobin1 in the regulation of salinity stress induced nitro-oxidative stress in plants is not known. Here we characterized the role of Pgb-mediated NO in salinity tolerance by regulation of nitro-oxidative stress using Pgb1 overexpressing (Pgb1-OE) and silencing lines (pgb1-AS) of Arabidopsis. We found that imposing salinity leads to enhanced expression of Pgb1. NO measurement by both chemiluminescence and DAF-FM-DA suggested that salinity stress induces NO production. Pgb1-OE lines showed reduced levels of NO, which is accompanied by reduced superoxide and H2O2 levels. On the contrary, pgb1-AS lines showed increased NO and ROS under salt stress. Further, gene expression analysis revealed an elevated expression of antioxidant genes in Pgb1-OE line in comparison to WT and pgb1-AS lines under salinity stress. Pgb1-OE lines showed enhanced survival, which is correlated with reduced peroxynitrite and tyrosine nitration, and an opposite effect was observed in pgb1-AS lines along with increased cell death. Taken together, our study revealed that modulation of Pgb1 enhances tolerance to salinity-induced nitro-oxidative stress.

The gut-brain-heart axis represents a dynamic interplay between the gut microbiota, cognitive function, and cardiovascular health, with profound implications for understanding and managing chronic diseases. In dysbiosis, a disruption in microbial balance contributes to neuro-inflammation, mood disorders, neurodegenerative diseases, and cardiovascular conditions such as atherosclerosis and hypertension. To date, researchers explored different mechanism through which gut microbial communities influence the activities of brain and heart. In order to understand these mechanisms summative, in this review, we focused on key communication pathways between microbiota-gut-brain-heart, such as vagus nerve, gut-derived metabolites, and systemic inflammation. Furthermore, the review discusses the bidirectional nature of these relationships, where cardiovascular and cognitive health mutually influence one another. Therapeutic interventions, including probiotics, dietary modifications, biotechnological approach and lifestyle changes are evaluated for their potential to modulate the gut-brain-heart axis and improve health outcomes. Despite significant advances, challenges remain in understanding the complex interactions within this axis. Future research directions emphasize personalized medicine approaches and the potential of microbiome-targeted therapies to revolutionize the prevention and treatment of cognitive and cardiovascular disorders.

Delta lactones are fatty acid-derived aroma compounds that hold tremendous commercial value. As consumer demand for natural flavours continues to rise, the bioproduction of δ-lactones, including δ-decalactone and δ-dodecalactone, is attracting substantial interest. Our study brings forth a novel approach to the bioproduction of δ-lactones from glucose, deviating from existing methods that primarily rely on the biotransformation of fatty acids. The high cost of fatty acid raw material constrains the commercial viability of this traditional approach. We engineered surface-lipid producing type I polyketide synthase (PKS) from Mycobacterium smegmatis by incorporating macrolactone thioesterase (TE) domain. Two out of three fusion constructs produced an appropriately engineered PKS-TE fusion protein that facilitated the synthesis of δ-lactones. When grown on glucose as the sole carbon source, recombinant E. coli expressing the engineered PKS-TE fusion protein successfully made δ-lactones ranging from C8-C18 acyl chains. Our research further highlights the potential of Mycobacterium smegmatis as a cell factory for producing fatty acid-based δ-lactones. By genetically designing and engineering Mycobacterium smegmatis to express PKS-TE fusion protein, we achieved bioproduction of various δ-lactones. Batch fermentation of the engineered E. coli strain fed with 2 % glucose produced 786 mg/L of δ-dodecalactone and 444 mg/L of δ-decalactone at 120 h, underscoring the efficacy of our approach. Thus, this study is the first to demonstrate a methodology for redirecting primary metabolic intermediates towards δ-lactone biosynthesis in engineered bacteria, enabling the use of inexpensive and renewable feedstocks.