Physiological effects of long-term saline-alkaline stress on the gills of Acanthopagrus latus: A combined analysis of transcriptomics and metabolomics.

Drought stress inhibits oat growth and yield. The application of fulvic acid (FA) can improve the drought resistance of oats, but the corresponding molecular mechanism of FA-mediated drought resistance remains unclear. Here, we studied the effects of FA on the drought tolerance of oat leaves through physiological, transcriptomic, and metabolomics analyses, and identified FA-induced genes and metabolites related to drought tolerance. Physiological analysis showed that under drought stress, FA increased the relative water and chlorophyll contents of oat leaves, enhanced the activity of antioxidant enzymes (SOD, POD, PAL, CAT and 4CL), inhibited the accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and dehydroascorbic acid (DHA), reduced the degree of oxidative damage in oat leaves, improved the drought resistance of oats, and promoted the growth of oat plants. Transcriptome and metabolite analyses revealed 652 differentially expressed genes (DEGs) and 571 differentially expressed metabolites (DEMs) in FA-treated oat leaves under drought stress. These DEGs and DEMs are involved in a variety of biological processes, such as phenylspropanoid biosynthesis and glutathione metabolism pathways. Additionally, FA may be involved in regulating the role of DEGs and DEMs in phenylpropanoid biosynthesis and glutathione metabolism under drought stress. In conclusion, our results suggest that FA promotes oat growth under drought stress by attenuating membrane lipid peroxidation and regulating the antioxidant system, phenylpropanoid biosynthesis, and glutathione metabolism pathways in oat leaves. This study provides new insights into the complex mechanisms by which FA improves drought tolerance in crops.

Aluminum (Al) toxicity severely restricts crop growth and productivity in acidic soils. The rubber tree is one of the most economically important crops in tropical regions, which is tolerant to high concentrations of Al in sand or hydroponic culture conditions compared with other plants that have been reported. However, the mechanisms of Al tolerance in rubber trees remain unknown. In this study, we conducted a transcriptome and metabolome analysis for rubber tree sapling roots treated with 200 mM Al for 0 (CK), 2 or 5 days, respectively. Compared with the CK, a total of 9534 differentially expressed genes (DEGs) and 3821 differentially expressed metabolites (DEMs) were identified in 2 d of Al treatment. There were 10,373 DEGs and 4636 DEMs after 5 d of Al treatment, and 1626 DEGs and 1674 DEMs between 2 and 5 d of Al treatment. The DEGs mainly concentrated in transporters, transcription factors (TFs), cell wall biosynthesis and antioxidant systems, and the DEMs were mainly focused on lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds, phenylpropanoids and polyketides. The combined transcriptome and metabolome analysis indicated DEGs and DEMs involved in ABC transporters, glutathione metabolism, flavonoid biosynthesis and phenylalanine metabolic pathways were identified to be closely associated with the Al tolerance of rubber trees. Our study elucidated the mechanism of rubber trees’ tolerance to Al at the transcriptional and metabolic levels, which provides a theoretical basis for the study of Al tolerance both for rubber trees and other woody plants.

Integrated application of multi-omics approach and biochemical assays provides insights into physiological responses to saline-alkaline stress in the gills of crucian carp (Carassius auratus)

Nitrogen is one of the most important mineral elements for plant growth and development. Excessive nitrogen application not only pollutes the environment, but also reduces the quality of crops. However, are few studies on the mechanism of barley tolerance to low nitrogen at both the transcriptome and metabolomics levels. In this study, the nitrogen-efficient genotype (W26) and the nitrogen-sensitive genotype (W20) of barley were treated with low nitrogen (LN) for 3 days and 18 days, then treated with resupplied nitrogen (RN) from 18 to 21 days. Later, the biomass and the nitrogen content were measured, and RNA-seq and metabolites were analyzed. The nitrogen use efficiency (NUE) of W26 and W20 treated with LN for 21 days was estimated by nitrogen content and dry weight, and the values were 87.54% and 61.74%, respectively. It turned out to have a significant difference in the two genotypes under the LN condition. According to the transcriptome analysis, 7926 differentially expressed genes (DEGs) and 7537 DEGs were identified in the leaves of W26 and W20, respectively, and 6579 DEGs and 7128 DEGs were found in the roots of W26 and W20, respectively. After analysis of the metabolites, 458 differentially expressed metabolites (DAMs) and 425 DAMs were found in the leaves of W26 and W20, respectively, and 486 DAMs and 368 DAMs were found in the roots of W26 and W20, respectively. According to the KEGG joint analysis of DEGs and DAMs, it was discovered that glutathione (GSH) metabolism was the pathway of significant enrichment in the leaves of both W26 and W20. In this study, the metabolic pathways of nitrogen metabolism and GSH metabolism of barley under nitrogen were constructed based on the related DAMs and DEGs. In leaves, GSH, amino acids, and amides were the main identified DAMs, while in roots, GSH, amino acids, and phenylpropanes were mainly found DAMs. Finally, some nitrogen-efficient candidate genes and metabolites were selected based on the results of this study. The responses of W26 and W20 to low nitrogen stress were significantly different at the transcriptional and metabolic levels. The candidate genes that have been screened will be verified in future. These data not only provide new insights into how barley responds to LN, but also provide new directions for studying the molecular mechanisms of barley under abiotic stress.

BackgroundMegalobrama amblycephala presents unsynchronized growth, which affects its productivity and profitability. The liver is essential for substance exchange and energy metabolism, significantly influencing the growth of fish.ResultsTo investigate the differential metabolites and genes governing growth, and understand the mechanism underlying their unsynchronized growth, we conducted comprehensive transcriptomic and metabolomic analyses of liver from fast-growing (FG) and slow-growing (SG) M. amblycephala individuals. A total of 2,097 differentially expressed genes (DEGs) were identified between FG and SG, with 830 genes exhibiting significantly higher expression level in FG. KEGG and GO enrichment analysis indicated that the DEGs with higher expression level were significantly correlated with insulin signaling pathway, steroid hormone and lipid metabolism related pathway (PPAR signaling pathway and fatty acid degradation). In the metabolomic analysis, 224 differentially expressed metabolites (DEMs) were detected, of which 128 were significantly more abundant in FG. These more abundant DEMs were prominently enriched in pathways associated with cell proliferation and energy metabolism (Oxidative phosphorylation, mTOR signaling pathway and FoxO signaling pathway). In addition, DEGs and DEMs in adenosine diphosphate (ATP) hydrolysis activity and associate with fatty acid metabolism, glucose metabolism, and amino acid metabolism pathways were both found in the transcriptomic and metabolomic integrated data. These findings suggest that the large amounts of energy generated by fatty acid, glucose metabolism and other energy metabolism pathway promote the rapid growth of FG.ConclusionsThis research is the first to integrate metabolomic and transcriptomic analyses of liver to identify key genes, metabolites, and pathways to uncover the molecular and metabolic mechanisms of unsynchronized growth in M. amblycephala. The identified metabolic and genes can be potential targets for selective breeding programs to improve growth performance in aquaculture.

α-Ketoglutarate modulates the mechanisms of toxicity in crucian carp kidneys chronically exposed to NaHCO3: Metabolomics insights.

Background/Objectives: Sweet potato is a tropical and subtropical crop and its growth and yield are susceptible to low-temperature stress. However, the molecular mechanisms underlying the low temperature stress of sweetpotato are unknown. Methods: In this work, combined transcriptome and metabolism analysis was employed to investigate the low-temperature responses of two sweet potato cultivars, namely, the low-temperature-resistant cultivar “X33” and the low-temperature-sensitive cultivar “W7”. Results: The differentially expressed metabolites (DEMs) of X33 at different time stages clustered in five profiles, while they clustered in four profiles of W7 with significant differences. Differentially expressed genes (DEGs) in X33 and W7 at different time points clustered in five profiles. More DEGs exhibited continuous or persistent positive responses to low-temperature stress in X33 than in W7. There were 1918 continuously upregulated genes and 6410 persistent upregulated genes in X33, whereas 1781 and 5804 were found in W7, respectively. Core genes involved in Ca2+ signaling, MAPK cascades, the reactive oxygen species (ROS) signaling pathway, and transcription factor families (including bHLH, NAC, and WRKY) may play significant roles in response to low temperature in sweet potato. Thirty-one common differentially expressed metabolites (DEMs) were identified in the two cultivars in response to low temperature. The KEGG analysis of these common DEMs mainly belonged to isoquinoline alkaloid biosynthesis, phosphonate and phosphinate metabolism, flavonoid biosynthesis, cysteine and methionine metabolism, glycine, serine, and threonine metabolism, ABC transporters, and glycerophospholipid metabolism. Five DEMs with identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were selected for correlation analysis. KEGG enrichment analysis showed that the carbohydrate metabolism, phenylpropanoid metabolism, and glutathione metabolism pathways were significantly enriched and played vital roles in low-temperature resistance in sweet potato. Conclusions: These findings contribute to a deeper understanding of the molecular mechanisms underlying plant cold tolerance and offer targets for molecular breeding efforts to enhance low-temperature resistance.

ObjectivePrecocious puberty (PP) is a prevalent endocrine disorder affecting the physical and mental wellbeing of children. Identifying the triggering factors of PP has become a central issue. This study seeks to investigate the metabolomic and transcriptomic alterations in PP.Material and methodsFirst, 37 school-aged girls diagnosed with PP and 25 age-matched prepubertal control girls were recruited, and the fecal samples were collected for non-targeted metabolomic analysis to screen for differentially expressed metabolites (DEMs). Subsequently, an animal model of PP was constructed by danazol administration to neonatal female rats, and both fecal non-targeted metabolomics and serum next-generation transcriptomic sequencing were performed to screen DEMs and differentially expressed genes (DEGs) in PP. Moreover, the DEM co-existing in clinical and animal models was administrated to PP rats to explore the role of the target metabolite in PP.ResultsA total of 24 DEMs in PP clinical samples and 180 DEMs and 425 DEGs in PP animal samples were identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that these DEMs and DEGs were enriched in disease-associated pathways, including fatty acid synthesis, glycerolipid metabolism, pyrimidine metabolism, steroid hormone biosynthesis, progesterone-mediated oocyte maturation, and gonadotropin-releasing hormone (GnRH) signaling pathway, forming a tight DEM–DEG pathway regulatory network. Further DEM validation demonstrated that thymine supplementation delayed the opening of the vagina and development of PP in model rats.ConclusionThis study reveals that the metabolomic and transcriptomic changes, along with enriched pathways, are implicated in PP based on clinical and animal analyses. The findings may provide new strategies and research avenues for PP treatment.

Integrated multi-omics reveals the interactive mechanisms of antioxidant defense, energy metabolism, and programmed cell death in cadmium tolerance of Elymus nutans Griseb.

Characterization, functional analysis, and expression levels of three carbonic anhydrases in response to pH and saline–alkaline stresses in the ridgetail white prawn Exopalaemon carinicauda

Effects of chronic saline-alkaline stress on gill, liver and intestinal histology, biochemical, and immune indexes in Amur minnow (Phoxinus lagowskii)

Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma (OPA), and its pathogenesis is primarily mediated by the viral envelope (Env) protein. However, the detailed oncogenic mechanisms underlying JSRV infection remain incompletely understood. In this study, we integrated transcriptomic and metabolomic analyses to characterize JSRV Env-induced alterations in human bronchial epithelial BEAS-2B (cells). BEAS-2B cells transfected with the pcDNA4.0myc-his-JSRV-env plasmid, those transfected with the empty pcDNA4.0myc-his vector, and untreated BEAS-2B cells served as the experimental, negative control, and blank control groups, respectively. Transcriptomic analysis identified a total of 2733 differentially expressed genes (DEGs). Specifically, relative to the blank and negative control groups, 1178 genes were upregulated and 307 were downregulated in the JSRV-env group. These DEGs were significantly enriched in pathways related to altered cellular energy metabolism, cell cycle regulation, and oncogenic signaling. Metabolomic analysis revealed 451 differentially expressed metabolites (DEMs), with 192 detected in positive ion mode and 259 in negative ion mode. Compared with both control groups, the JSRV-env group exhibited 33 upregulated and 46 downregulated DEMs in positive ion mode, as well as 22 upregulated and 55 downregulated DEMs in negative ion mode. These DEMs were significantly enriched in pathways such as cellular metabolism, purine metabolism, amino acid metabolism, and the tricarboxylic acid cycle. Notably, cellular and mitochondrial energy metabolism pathways were closely linked. Analyses of mitochondrial- and mitophagy-related genes, alongside an integrated transcriptomic and metabolomic evaluation of their interactions, suggested mitochondrial damage and the potential activation of mitophagy. Furthermore, JSRV Env-transformed BEAS-2B cells exhibited elevated reactive oxygen species, decreased mitochondrial membrane potential, and abnormal mitochondrial morphology-characterized by swelling, as well as fragmented, dissolved, or disappearing cristae-along with the presence of myelin-like mitochondrial lesions and mitophagosomes. Mitochondrial and lysosomal probe co-localization further confirmed mitochondrial degradation in the transformed cells. Overall, these results highlight the potential involvement of altered mitochondrial energy metabolism and mitophagy in JSRV Env-induced BEAS-2B cell transformation. These findings offer novel insights into the mechanisms of viral oncoproteins, cellular metabolic reprogramming, and mitophagy, while identifying potential targets for understanding JSRV pathogenesis.

Key role of hormone signal transduction and lipid metabolism in the development of Nitraria sibirica leaves: An integrated metabolomic and transcriptomic analysis

IntroductionIndigofera stachyodes Lindl. is a perennial shrub belonging to the Fabaceae family that has been traditionally utilized as a medicinal plant by ethnic minority groups in Guizhou Province, China. This species exhibits significant ethnopharmacological value in local traditional medicine systems. The plant predominantly inhabits karst mountainous regions characterized by frequent drought stress, which represents a typical harsh habitat for plant growth. Notably, drought conditions particularly impair the establishment and development of I. stachyodes seedlings. However, the molecular mechanisms underlying its drought tolerance and adaptive responses remain largely unexplored, warranting further investigation at the molecular level.MethodsWe conducted pot-based water control experiments to subject I. stachyodes seedlings to drought stress treatments (CK, T0, T2). Root tissues from each treatment group were analyzed using transcriptomics (RNA-seq) and metabolomics (LC-MS/GC-MS) approaches to identify differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs). Through integrated analysis of DEGs and DEMs, we performed KEGG pathway enrichment and constructed co-expression networks to elucidate the molecular mechanisms underlying drought stress responses in the roots of I. stachyodes seedlings.ResultsA total of 11,509 DEGs were detected in the transcriptome. Among them, the CK vs T0 group shared 7,191 DEGs, the CK vs T2 group shared 1,264 DEGs, and the T2 vs T0 group shared 3,054 DEGs. In the metabolome, a total of 622 metabolites were detected. Among them, the CK vs T0 group shared 187 DEMs, the CK vs T2 group shared 127 DEMs, and the T2 vs T0 group shared 86 DEMs. The transcriptome-metabolome analysis revealed that the roots of I. stachyodes seedlings regulate metabolic balance through the phenylpropanoid biosynthesis pathway and the flavonoid biosynthesis pathway when subjected to varying degrees of drought stress. Metabolites such as p-coumaric acid, sinapine malate, eugenol, coumestrol, medicarpin, prunin, isosakuranetin, vitexin, gallocatechin, catechin, garbunzol and dihydromyricetin, along with genes including PAL, C4H, COMT, 4CL, CHS, DFR, HIDH, I2’H, IF7GT, IF7MAT, IFR, VR, PTS and IFS are potential key substances that enable the roots of I. stachyodes seedlings to resist drought stress.DiscussionThese results elucidate that the roots of I. stachyodes seedlings can resist drought stress and adapt to drought environments by regulating the expression of genes and the synthesis of metabolites in the flavonoid and phenylpropanoid metabolic pathways, providing a foundation to facilitate the domestication of wild I. stachyodes.

Seed germination is an important development process in plant growth. The phytohormone abscisic acid (ABA) plays a critical role during seed germination. However, the mechanism of rapeseed in response to ABA is still elusive. In order to understand changes of rapeseed under exogenous ABA treatment, we explored differentially expressed metabolites (DEMs) and the differentially expressed genes (DEGs) between mock- and ABA-treated seedlings. A widely targeted LC-MS/MS based metabolomics were used to identify and quantify metabolic changes in response to ABA during seed germination, and a total of 186 significantly DEMs were identified. There are many compounds which are involved in ABA stimuli, especially some specific ABA transportation-related metabolites such as starches and lipids were screened out. Meanwhile, a total of 4440 significantly DEGs were identified by transcriptomic analyses. There was a significant enrichment of DEGs related to phenylpropanoid and cell wall organization. It suggests that exogenous ABA mainly affects seed germination by regulating cell wall loosening. Finally, the correlation analysis of the key DEMs and DEGs indicates that many DEGs play a direct or indirect regulatory role in DEMs metabolism. The integrative analysis between DEGs and DEMs suggests that the starch and sucrose pathways were the key pathway in ABA responses. The two metabolites from starch and sucrose pathways, levan and cellobiose, both were found significantly down-regulated in ABA-treated seedlings. These comprehensive metabolic and transcript analyses provide useful information for the subsequent post-transcriptional modification and post germination growth of rapeseed in response to ABA signals and stresses.