Effects of Nitrogen Sources on Selected Biochemical Properties of Oryza Sativa L. Cultivars

Fifteen recommended rice cultivars were used in this experiment. They were Setanjung, Muda, MR 84, RU 2242-1-1, IR 64, MR 185, MR 151, MR 159, MR 167, MRQ 34, MR 207, MR 209, MR 211, MR 219 and MR 220. Leaves of three-week old seedlings were analyzed for nitrogen assimilating enzymes, namely nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) activities to evaluate the assimilation of N supply whereas ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity was use as an indicator for photosynthesis. The end products of N and C metabolism such as chlorophyll, soluble protein, fresh weight, soluble carbohydrates and starch contents were also analyzed. These biochemical evaluation were carried out in three different growth medium known as ‘control ~ without nitrogen sources’, ‘NO3 - containing medium’ and ‘NH4 + containing medium’ to determine the effect of different N sources. Treatments were laid out in split-plots in a randomized complete block design with N treatment as the main plot and cultivars as the subplot. In the study obtained, the addition of external N sources did not help in accelerating the activities of N assimilating enzymes (NR, NiR, GS, GOGAT and GDH) as well as Rubisco when compared to control medium. In the leaves of three-week old seedlings, NR, NiR, GS and Rubisco activities were negatively related with the availability of N sources (-88%, -28%, -22% and -13%, respectively). GOGAT activity was demonstrated not to be influenced by the addition of N sources (no significant different) whereas GDH activity was higher in control (+51%) and NH4 + (+20%) containing medium as compared to NO3 -. In investigation of the effects of different nitrogen sources on selected N and C metabolites, positive correlation was observed. The increment of nearly 40% under nitrate supply and 62% in ammonium of the soluble protein content was seen with the external addition of N. Similarly, there was also an increased in the fresh weight (FW) content of nearly 0.8-fold in NO3 - grown plants to 0.2-fold in NH4 + fed plants when different N sources were applied (the increased in ammonium supply was not statistically significant in comparison with control). This lower FW content under ammonium supply could be the consequences of the slight chlorosis observed in the leaves tissue. In contrast, chlorophyll content happened to be lower in both NO3 - and NH4 + containing medium, with a reduction of 30% and 14%, respectively. Soluble carbohydrates content was slightly higher under nitrate supply than in ammonium whereas the control medium was found to possess higher starch content. Lower starch content in both medium (NO3 - and NH4 +) could possibly relate to higher nitrogen use efficiency which resulted in an increase of soluble protein and FW contents. Apparently, the antioxidative property of ascorbic acid content was significantly higher in both control and NH4 + containing medium, whereas glutathione reductase (GR) activity was highest under ammonium supply. Cultivars as the subplot were found to demonstrate high significant evidence (P < 0.001) and were in consistency among the entire biochemical analyses, indicating genetic materials (15 rice cultivars) being one of the influential factor in regulating the outcome of the biochemical results obtained

Impact of within-row plant spacing and fixed fruit setting on yield and quality of rockmelon fruit cultivated by drip irrigation in a greenhouse

Experiments were conducted in a ventilated greenhouse located in a commercial farm (2°56′N, 101°54′E) at Broga, Malaysia from 2014 to 2015. The objective of this study was to evaluate the interaction between within-row plant spacing and fruit-set position on the yield and quality of 'Glamour' rockmelon fruit. Rockmelon was grown at 1.57 m between rows with 0.15 m, 0.30 m, and 0.60 m of within-row plant spacing. The plants were fixed to set fruit at T1 (one fruit, 1-7 lateral branches), T2 (one fruit, 8-14 lateral branches), T3 (two fruits, 1-7 lateral branches), and T4 (two fruits, 8-14 lateral branches). As within-row plant spacing decreased from 0.30 m to 0.15 m, yield per ha was increased by 58.1%, and a 3.7-fold increase in yield was seen from 0.60-m to 0.15-m spacing. Total soluble solids (11.96°Brix) and total carbohydrate content (86.60 g GE 100 g DW) were highest at a plant spacing of 0.60 m. Our results demonstrated that the interaction between 0.30-m within-row plant spacing with two fruits set at 8-14 lateral branches showed the most commercially viable outcome in fresh fruit weight as these conditions produced two fruits with an average fruit weight of 2.20 kg per fruit

Improvement of hydrogen yield of ethanol-producing Escherichia coli recombinants in acidic conditions

Background: An effective single culture with high glycerol consumption and hydrogen and ethanol coproduction yield is still in demand. A locally isolated glycerol-consuming Escherichia coli SS1 was found to produce lower hydrogen levels under optimized ethanol production conditions. Molecular approach was proposed to improve the hydrogen yield of E. coli SS1 while maintaining the ethanol yield, particularly in acidic conditions. Therefore, the effect of an additional copy of the native hydrogenase gene hycE and recombinant clostridial hydrogenase gene hydA on hydrogen production by E. coli SS1 at low pH was investigated. Results: Recombinant E. coli with an additional copy of hycE or clostridial hydA was used for fermentation using 10 g/L (108.7 mmol/L) of glycerol with an initial pH of 5.8. The recombinant E. coli with hycE and recombinant E. coli with hydA showed 41% and 20% higher hydrogen yield than wild-type SS1 (0.46 \ub1 0.01 mol/mol glycerol), respectively. The ethanol yield of recombinant E. coli with hycE (0.50 \ub1 0.02 mol/mol glycerol) was approximately 30% lower than that of wild-type SS1, whereas the ethanol yield of recombinant E. coli with hydA (0.68 \ub1 0.09 mol/mol glycerol) was comparable to that of wild-type SS1. Conclusions: Insertion of either hycE or hydA can improve the hydrogen yield with an initial pH of 5.8. The recombinant E. coli with hydA could retain ethanol yield despite high hydrogen production, suggesting that clostridial hydA has an advantage over the hycE gene in hydrogen and ethanol coproduction under acidic conditions. This study could serve as a useful guidance for the future development of an effective strain coproducing hydrogen and ethanol

Improvement of hydrogen yield of ethanol-producing Escherichia coli recombinants in acidic conditions

Background: An effective single culture with high glycerol consumption and hydrogen and ethanol coproduction yield is still in demand. A locally isolated glycerol-consuming Escherichia coli SS1 was found to produce lower hydrogen levels under optimized ethanol production conditions. Molecular approach was proposed to improve the hydrogen yield of E. coli SS1 while maintaining the ethanol yield, particularly in acidic conditions. Therefore, the effect of an additional copy of the native hydrogenase gene hycE and recombinant clostridial hydrogenase gene hydA on hydrogen production by E. coli SS1 at low pH was investigated. Results: Recombinant E. coli with an additional copy of hycE or clostridial hydAwas used for fermentation using 10 g/L (108.7 mmol/L) of glycerol with an initial pH of 5.8. The recombinant E. coli with hycE and recombinant E. coli with hydA showed 41% and 20% higher hydrogen yield than wild-type SS1 (0.46 ± 0.01 mol/mol glycerol), respectively. The ethanol yield of recombinant E. coli with hycE (0.50 ± 0.02 mol/mol glycerol) was approximately 30% lower than that of wild-type SS1, whereas the ethanol yield of recombinant E. coli with hydA (0.68 ± 0.09 mol/mol glycerol) was comparable to that of wild-type SS1. Conclusions: Insertion of either hycE or hydA can improve the hydrogen yield with an initial pH of 5.8. The recombinant E. coli with hydA could retain ethanol yield despite high hydrogen production, suggesting that clostridial hydAhas an advantage over the hycE gene in hydrogen and ethanol coproduction under acidic conditions. This study could serve as a useful guidance for the future development of an effective strain coproducing hydrogen and ethanol

Co-culture systems for the production of secondary metabolites: current and future prospects

Microorganisms are the great sources of Natural Products (NPs); these are imperative to their survival apart from conferring competitiveness amongst each other within their environmental niches. Primary and secondary metabolites are the two major classes of NPs that help in cell development, where antimicrobial activity is closely linked with secondary metabolites. To capitalize on the effects of secondary metabolites, co-culture methods have been often used to develop an artificial microbial community that promotes the action of these metabolites. Different analytical techniques will subsequently be employed based on the metabolite specificity and sensitivity to further enhance the metabolite induction. Liquid Chromatography-Mass Spectrometry (LC-MS) and Gas Chromatography (GC)-MS are commonly used for metabolite separation while Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) have been used as tools to elucidate the structure of compounds. This review intends to discuss current systems in use for co-culture in addition to its advantages, with discourse into the investigation of specific techniques in use for the detailed study of secondary metabolites. Further advancements and focus on co-culture technologies are required to fully realize the massive potential in synthetic biological systems

Functional and structural analysis of non-synonymous single nucleotide polymorphisms (nsSNPs) in the MYB oncoproteins associated with human cancer

MYB proteins are highly conserved DNA-binding domains (DBD) and mutations in MYB oncoproteins have been reported to cause aberrant and augmented cancer progression. Identification of MYB molecular biomarkers predictive of cancer progression can be used for improving cancer management. To address this, a biomarker discovery pipeline was employed in investigating deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) in predicting damaging and potential alterations on the properties of proteins. The nsSNP of the MYB family; MYB, MYBL1, and MYBL2 was extracted from the NCBI database. Five in silico tools (PROVEAN, SIFT, PolyPhen-2, SNPs&GO and PhD-SNP) were utilized to investigate the outcomes of nsSNPs. A total of 45 nsSNPs were predicted as high-risk and damaging, and were subjected to PMut and I-Mutant 2.0 for protein stability analysis. This resulted in 32 nsSNPs with decreased stability with a DDG score lower than − 0.5, indicating damaging effect. G111S, N183S, G122S, and S178C located within the helix-turn-helix (HTH) domain were predicted to be conserved, further posttranslational modifications and 3-D protein analysis indicated these nsSNPs to shift DNA-binding specificity of the protein thus altering the protein function. Findings from this study would help in the field of pharmacogenomic and cancer therapy towards better intervention and management of cancer

Association and Interaction Effect of AGTR1 and AGTR2 Gene Polymorphisms with Dietary Pattern on Metabolic Risk Factors of Cardiovascular Disease in Malaysian Adults

Gene-diet interaction using a multifactorial approach is preferred to study the multiple risk factors of cardiovascular disease (CVD). This study examined the association and gene-diet interaction effects of the angiotensin II type 1 receptor (AGTR1) gene (rs5186), and type 2 receptor (AGTR2) gene (rs1403543) polymorphisms on metabolic risk factors of CVD in Malaysian adults. CVD parameters (BMI, blood pressure, glycated hemoglobin, total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and TC/HDL-C ratio), and constructed dietary patterns “vegetables, fruits, and soy diet” (VFSD), and “rice, egg, and fish diet” (REFD) were obtained from previous studies. Genotyping analysis was performed by real-time PCR using Taqman probes. The subjects were 507 adults (151 Malays; 179 Chinese; and 177 Indians). Significant genetic associations were obtained on blood lipids for rs5186 in Malays and Chinese, and rs1403543 in Chinese females. The significant gene-diet interaction effects after adjusting for potential confounders were: rs5186 × VFSD on blood pressure in Malays (p = 0.016), and in Chinese on blood lipids for rs5186 × REFD (p = 0.009–0.023), and rs1403543 × VFSD in female subjects (p = 0.001–0.011). Malays and Chinese showed higher risk for blood pressure and/or lipids involving rs5186 and rs1403543 SNPs together with gene-diet interactions, but not Indians

Association of Stress, Mental Health, and <i>VEGFR-2</i> Gene Polymorphisms with Cardiometabolic Risk in Chinese Malaysian Adults

Gene-environment (G &#215; E) interactions involving job stress and mental health on risk factors of cardiovascular disease (CVD) are minimally explored. This study examined the association and G &#215; E interaction effects of vascular endothelial growth factor receptor-2 (VEGFR-2) gene polymorphisms (rs1870377, rs2071559) on cardiometabolic risk in Chinese Malaysian adults. Questionnaires: Job Stress Scale (JSS); Depression, Anxiety, and Stress Scale (DASS-21); and Rhode Island Stress and Coping Inventory (RISCI) were used to measure job stress, mental health, and coping with perceived stress. Cardiometabolic risk parameters were evaluated in plasma and genotyping analysis was performed by real-time polymerase chain reaction. The subjects were 127 Chinese Malaysian adults. The allele frequencies for rs1870377 (A allele and T allele) and rs2071557 (A allele and T allele) polymorphisms were 0.48 and 0.52, and 0.37 and 0.63, respectively. Significant correlations include scores from JSS dimensions with blood glucose (BG) (p = 0.025&#8722;0.045), DASS-21 dimensions with blood pressure, BMI, and uric acid (p = 0.029&#8722;0.047), and RISCI with blood pressure and BG (p = 0.016&#8722;0.049). Significant G &#215; E interactions were obtained for: rs1870377 with stress on total cholesterol (p = 0.035), low density lipoprotein cholesterol (p = 0.019), and apolipoprotein B100 (p = 0.004); and rs2071559 with anxiety on blood pressure (p = 0.006&#8722;0.045). The significant G &#215; E interactions prompt actions for managing stress and anxiety for the prevention of CVD