Transcriptional and Physiological Analyses to Assess the Effects of a Novel Biostimulant in Tomato

This work aimed to study the effects in tomato (Solanum lycopersicum L.) of foliar applications of a novel calcium-based biostimulant (SOB01) using an omics approach involving transcriptomics and physiological profiling. A calcium-chloride fertilizer (SOB02) was used as a product reference standard. Plants were grown under well-watered (WW) and water stress (WS) conditions in a growth chamber. We firstly compared the transcriptome profile of treated and untreated tomato plants using the software RStudio. Totally, 968 and 1,657 differentially expressed genes (DEGs) (adj-p-value < 0.1 and |log2(fold change)| ≥ 1) were identified after SOB01 and SOB02 leaf treatments, respectively. Expression patterns of 9 DEGs involved in nutrient metabolism and osmotic stress tolerance were validated by real-time quantitative reverse transcription PCR (RT-qPCR) analysis. Principal component analysis (PCA) on RT-qPCR results highlighted that the gene expression profiles after SOB01 treatment in different water regimes were clustering together, suggesting that the expression pattern of the analyzed genes in well water and water stress plants was similar in the presence of SOB01 treatment. Physiological analyses demonstrated that the biostimulant application increased the photosynthetic rate and the chlorophyll content under water deficiency compared to the standard fertilizer and led to a higher yield in terms of fruit dry matter and a reduction in the number of cracked fruits. In conclusion, transcriptome and physiological profiling provided comprehensive information on the biostimulant effects highlighting that SOB01 applications improved the ability of the tomato plants to mitigate the negative effects of water stress.

Chemosensory Proteins (CSPs) in the Cotton Bollworm Helicoverpa armigera

Chemosensory proteins (CSPs) are a family of small, soluble proteins that play a crucial role in transporting odorant and pheromone molecules in the insect chemosensory system. Recent studies reveal that they also function in development, nutrient metabolism and insecticide resistance. In-depth and systematic characterization of previously unknown CSPs will be valuable to investigate more detailed functionalities of this protein family. Here, we identified 27 CSP genes from the genome and transcriptome sequences of cotton bollworm, Helicoverpa armigera (Hübner). The expression patterns of these genes were studied by using transcriptomic data obtained from different tissues and stages. The results demonstrate that H. armigera CSP genes are not only highly expressed in chemosensory tissues, such as antennae, mouthparts, and tarsi, but also in the salivary glands, cuticle epidermis, and hind gut. HarmCSP6 and 22 were selected as candidate CSPs for expression in Escherichia coli and purification. A new method was developed that significantly increased the HarmCSP6 and 22 expression levels as soluble recombinant proteins for purification. This study advances our understanding of insect CSPs and provides a new approach to highly express recombinant CSPs in E. coli.

Utilization of phytohormones for successful crop production under environmental stress conditions

Stress is an external factor that exerts a detrimental effect on overall growth of a plant. Environmental stress is a serious threat for sustainable crop production, and a main cause for food insecurity. Agricultural crops are exposed to a variety of environmental stresses including extreme temperatures and unfavorable chemical and physical soil conditions. Drought stress adversely affects some physiological and biochemical processes in plants, including transpiration, translocation of assimilates and nutrient metabolism. Salinity stress is responsible for loss of turgor, reduction in growth, wilting, leaf abscission, reduction in photosynthesis and respiration, loss of cellular integrity, tissue necrosis and finally death of the plant. Drought and salinity stress negatively affects the growth and yield of crop plants more than all the other stresses combined. Cold stress affects cellular components and metabolism, and temperature extremes impose stresses of variable severity that depend on the intensity and duration of the stress. Many approaches are being used to alleviate the deleterious effects of environmental stresses on successful agricultural crops production in recent years. Application of phytohormones (Abscisic acid, Indole-3-Aacetic Acid, Jasmonic acid and salicylic acid) is one of the curative measures to mitigate the environmental stresses in agricultural crops. Phytohormones play a significant role in enhancing stress tolerance and therefore, reduce the yield loss in crop plants. In this paper, the impacts of environmental stresses on productivity and physiological activities of crop plants, and the effective role of some phytohormones in alleviation of environmental stresses have been reviewed.

Exploring the Functional and Metabolic Effects of Feeding Garra Fish Meal to Broiler Chickens

The present study evaluated the metabolic and functional effects, beyond nutritive value, of feeding garra meal to broiler chickens. Three hundred twenty Sasso-breed day-old chicks were randomly assigned to four dietary treatments with either 0, 10, 20 or 30% garra meal added on top of a formulated starter and grower basal diets. The experiment lasted for 42 days. There was a gradual increase in feed intake and body weight gain with increasing garra meal addition (p < 0.05). Broiler chickens fed 30% garra meal were more efficient in converting feed to body weight and yielded the highest carcass weight (p < 0.05). Crude protein and crude fat digestibility coefficients were higher with the garra meal receiving groups with the highest values (74.8 ± 1.6 and 92.3 ± 0.6) recorded with 20% and 30% garra meal additions, respectively (p < 0.05). The increase in individual and total esterified carnitine concentrations in dried blood spots demonstrated the elevated metabolic rate with increasing garra meal addition (p < 0.05). A better supply of glucogenic substrate to the citric acid cycle was seen with garra meal addition due to the increase of propionylcarnitine to acetylcarnitine ratio (p < 0.05) while no effect was observed on ketogenesis as measured through the 3-hydroxybutyrylcarnitine to acetylcarnitine ratio (p > 0.05). Yet, it likely showed that part of the higher amino acids (Leucine, Methionine and Citrulline) uptake due to garra meal was used as glucogenic substrate (p < 0.05). Histo-morphology showed gradual increases in villus height, crypt depth and their ratio in the proximal parts of the intestine (duodenum and jejunum) with the opposite results observed in the more distal part (ileum) with garra meal addition (p < 0.05). It can be concluded that garra meal strongly improved broiler performance when added to a plant-based diet and only few parameters warranted for caution when using more up to 30% garra meal addition. Beyond growth performance, garra meal generated a shift to a more efficient digestion and nutrient metabolism, and induced changes in edible muscle that may aid in solving shortages in the Ethiopian human diet.

Bioavailability, Accumulation and Distribution of Toxic Metals (As, Cd, Ni and Pb) and Their Impact on Sinapis alba Plant Nutrient Metabolism

This study presents the behavior of white mustard seedlings Sinapis alba grown for three months in laboratory polluted soil containing As, Cd, Ni and Pb. Four different experiments were performed in which As was combined with the other three toxic metals in different combinations (As, AsCd, AsCdNi, AsCdNiPb), keeping the same concentrations of As and Cd in all tests and following the national soil quality regulations. The effects of these metals were monitored by the analytical control of metal concentrations in soil and plants, bioavailability tests of mobile metal fractions using three different extracting solutions (DTPA + TEA + CaCl2-DTPA, DTPA + CaCl2-CAT, and CH3COONH4 + EDTA-EDTA) and calculation of bioaccumulation and translocation factors. Additionally, micro, and macro-nutrients both in soil and plant (root, stem, leaves, flowers and seeds) were analyzed in order to evaluate the impact of toxic metals on plant nutrient metabolism. Metals were significantly and differently accumulated in the plant tissues, especially under AsCdNi and AsCdNiPb treatments. Significant differences (p < 0.05) in the concentration of both As and Cd were highlighted. Translocation could be influenced by the presence of other toxic metals, such as Cd, but also of essential metals, through the competition and antagonism processes existing in plant tissues. Significantly, more Cd and Ni levels were detected in leaves and flowers. Cd was also detected in seeds above the WHO limit, but the results are not statistically significant (p > 0.05). The extraction of metallic nutrients (Zn, Cu, Mn, Ni, Mg, K, Fe, Ca, Cr) in the plant was not influenced by the presence of toxic metal combinations, on the contrary, their translocation was more efficient in the aerial parts of the plants. No phytotoxic effects were recorded during the exposure period. The most efficient methods of metal extraction from soil were for As-CAT; Cd-all methods; Pb and Ni-DTPA. The Pearson correlations (r) between applied extraction methods and metal detection in plants showed positive correlations for all toxic metals as follows: As-CAT > DTPA > EDTA, Cd-DTPA > CAT > EDTA, Ni-EDTA = DTPA > CAT, Pb-EDTA = DTPA = CAT). The results revealed that Sinapis alba has a good ability to accumulate the most bioavailable metals Cd and Ni, to stabilize As at the root level and to block Pb in soil.

Geroscience approaches to obesity

Besides aging, obesity is the greatest risk factor for numerous chronic pathologies, including metabolic syndrome, type 2 diabetes, cardiovascular disease, hypertension, and cancer. Preventing and treating obesity would greatly reduce healthcare costs and the impact of the aging process, with estimated savings up to $145,000,000,000. Pharmacological interventions identified by geroscience may prove effective against diet-induced obesity. To test this hypothesis, we fed a 66% kcal/fat diet to nine-month-old C57Bl6/N mice for 6 weeks and treated them with either rapamycin, acarbose, or a combination thereof. Rapamycin, and to a lesser extent acarbose, prevented weight gain and fat accumulation in these mice. We detected increased expression of the Liver Activating Protein (LAP) isoform of the transcription factor CCAT/Enhancer Binding Protein β (C/EBPβ) in the liver of mice treated with rapamycin. C/EBPβ-LAP mediates some of the effects of caloric restriction on nutrient metabolism and increases lifespan in a mouse transgenic model. We tested whether independent activation of C/EBPβ-LAP would recapitulate the effects of rapamycin by treating mice on a high-fat diet with adefovir dipivoxil, a reverse transcriptase inhibitor that can activate LAP in vitro independently of mTOR inhibition. Adefovir dipivoxil reduced weight and fat mass accumulation in mice over the course of 6 weeks. Mice treated with adefovir dipivoxil showed increased expression of genes involved in β-oxidation and lipids mobilization, and reduced activation of fatty acid biosynthesis and lipid storage pathways. Our results identify C/EBPβ-LAP as a potential new target to improve lipid homeostasis in both aging and obesity.

Nutrient metabolism in the liver and muscle of juvenile blunt snout bream (Megalobrama amblycephala) in response to dietary methionine levels

A 75-day rearing trial was designed to study the response of juvenile Megalobrama amblycephala to dietary methionine (Met) levels. Three practical diets with graded Met levels (0.40%, 0.84% and 1.28% dry matter) were prepared to feed the juvenile fish. The results showed that the 0.84% Met diet significantly improved the growth compared with 0.40% diets. Compared with 0.84% and 1.28% Met, 0.40% Met significantly increased the hepatic lipid content, while decreasing the muscular lipid and glycogen contents. 0.40% Met decreased the protein levels of phospho-Eukaryotic initiation factor 4E binding protein-1 (p-4e-bp1), 4e-bp1 and Ribosomal protein S6 kinase 1 in the liver, compared with 0.84% diet, while an increasing trend was observed in the muscle. Met supplementation tended to decrease and increase lipid synthesis in the liver and muscle, respectively, via changing mRNA levels of sterol regulatory element-binding protein 1, fatty acid synthetase and acetyl-CoA carboxylase. 1.28% dietary Met promoted fatty acid β-oxidation and lipolysis in both the liver and muscle by increasing carnitine palmitoyl transferase 1, peroxisome proliferator activated receptor alpha, lipoprotein lipase and lipase mRNA levels. Compared with 0.40% and 0.84% dietary Met, 1.28% Met enhanced the mRNA levels of hepatic gluconeogenesis related genes phosphoenolpyruvate carboxykinase (pepck), and glucose-6-phosphatase, and muscular glycolysis related genes phosphofructokinase (pfk), and pyruvate kinase (pk). The mRNA levels of hepatic pfk, pk and glucokinase were markedly downregulated by 1.28% Met compared with 0.84% level. Muscular pepck, glycogen synthase, and hepatic glucose transporters 2 mRNA levels were induced by 1.28% Met. Generally, deficient Met level decreased the growth of juvenile Megalobrama amblycephala, and the different nutrient metabolism responses to dietary Met were revealed in the liver and muscle.

Changes in Growth Performance, Nutrient Metabolism, Antioxidant Defense and Immune Response After Fishmeal Was Replaced by Low-Gossypol Cottonseed Meal in Golden Pompano (Trachinotus ovatus)

The present study was designed to elucidate the changing pattern of growth performance, nutrient metabolism, antioxidant defense, and immune response after fishmeal (FM) was replaced by cottonseed meal (CSM). Four isonitrogenous and isolipidic experimental diets (42.5% crude protein, 14.0% crude lipid) were formulated to replace 0% (CSM0 diet), 20% (CSM20 diet), 40% (CSM40 diet), and 60% (CSM60 diet) of the FM protein with CSM. Juvenile golden pompano (Trachinotus ovatus) with an initial body weight of 24.8 ± 0.02 g were fed each diet for 6 weeks. The results showed that compared with the control diet, significant differences were not found in the weight gain ratio, specific growth performance, and apparent digestibility of dry matter and protein after 20% FM was replaced by CSM. Higher CSM replacement markedly decreased the growth performance (P &lt; 0.05). Moreover, the CSM20 and CSM40 diets did not depress the feed efficiency ratio and protein efficiency ratio compared with the CSM0 diet. Further exploring the physio-biochemical and molecular responses, the present study also showed that dietary 20–40% CSM replacement had no significant effect on altering the whole body, plasma nutrient contents, free amino acids, or whole-body fatty acid contents. Additionally, the CSM20 diet did not change the mRNA and protein phosphorylation levels of the key enzymes and regulators involved in target of rapamycin (TOR) and amino acid response (AAR) signaling, nutrient metabolism, immune response, and antioxidant defense. Higher CSM inclusion significantly varied the TOR and AAR signaling response, nutrient metabolism, immune response, and antioxidant defense. Based on the results, CSM could successfully replace 20% FM in the formulated diets for golden pompano. This study proposes the optimal inclusion level of CSM in the diet, which has an important significance in optimizing aquafeeds formulation.

Role of Epigallocatechin Gallate in Glucose, Lipid, and Protein Metabolism and L-Theanine in the Metabolism-Regulatory Effects of Epigallocatechin Gallate

Epigallocatechin gallate (EGCG) and L-theanine (LTA) are important bioactive components in tea that have shown promising effects on nutrient metabolism. However, whether EGCG alone or combined with LTA can regulate the glucose, lipid, and protein metabolism of healthy rats remains unclear. Therefore, we treated healthy rats with EGCG or the combination of EGCG and LTA (EGCG+LTA) to investigate the effects of EGCG on nutrient metabolism and the role of LTA in the metabolism-regulatory effects of EGCG. The results showed that compared with the control group, EGCG activated insulin and AMP-activated protein kinase (AMPK) signals, thus regulating glucose, lipid, and protein metabolism. Compared with EGCG, EGCG+LTA enhanced hepatic and muscle glycogen levels and suppressed phosphorylation of AMPK, glycogen synthase 2, mammalian target of rapamycin, and ribosomal protein S6 kinase. In addition, EGCG+LTA inhibited the expression of liver kinase B1, insulin receptor and insulin receptor substrate, and promoted the phosphorylation level of acetyl-CoA carboxylase. Furthermore, both EGCG and EGCG+LTA were harmless for young rats. In conclusion, EGCG activated AMPK and insulin pathways, thereby promoting glycolysis, glycogen, and protein synthesis and inhibiting fatty acid (FA) and cholesterol synthesis. However, LTA cooperated with EGCG to promote glycogen metabolism and suppressed the effect EGCG on FA and protein synthesis via AMPK signals.