Total Soluble Leaf Protein Research Articles

Insecticidal action of mammalian galectin-1-transfected Arabidopsis thaliana.

Galectins (GALs) are a family of mammalian sugar-binding proteins specific for β-galactosides. Our previous studies have shown that the larval development of the diamondback moth (Plutella xylostella) is significantly disturbed when fed with recombinant mammalian galectin 1 (GAL1) derived from Escherichia coli. To further explore its applicability, two GAL1-overexpressed Arabidopsis [GAL1-Arabidopsis (whole plant) and GAL1-Arabidopsis-vas (vascular bundle-specific)] lines were established for insecticidal activity and mechanism studies. The expression level of GAL1 in transgenic Arabidopsis is 1-0.5% (GAL1-Arabidopsis) and 0.08-0.01% (GAL1-Arabidopsis-vas) of total leaf soluble protein. Survival, body weight, and food consumption significantly decreased in a time-dependent manner in P. xylostella larvae (with chewing mouthparts) fed on GAL1-Arabidopsis. The mortality of Kolla paulula (with piercing-sucking mouthparts and xylem feeder) fed on GAL1-Arabidopsis-vas was also significantly higher than that fed on wild-type Arabidopsis (WT-Arabidopsis), but was lower than that fed on GAL1-Arabidopsis. The histochemical structure and results of immunostaining suggested that the binding of GAL1 to the midgut epithelium of P. xylostella fed on GAL1-Arabidopsis was dose- and time-dependent. Ultrastructural studies further showed the disruption of microvilli, abnormalities in epithelial cells, and fragments of the peritrophic membrane (PM) in P. xylostella larvae fed on GAL1-Arabidopsis. The insecticidal mechanism of GAL1 involves interference with PM integrity and suggests that GAL1 is a potential candidate for bioinsecticide development. © 2024 Society of Chemical Industry.

Improvement of Germination and Early Growth of Radish (Raphanus sativus L.) through Modulation of Seed Metabolic Processes.

Radish (Raphanus sativus L.) is a vegetable cultivated worldwide because of its large succulent hypocotyls. The priming method initiates metabolic processes at early stages and regulates the metabolic events in seed necessary for germination. This research was conducted to examine the influence of various priming treatments on physiological performance (germination, growth, lipid peroxidation, primary and secondary metabolism) and antioxidant activity of radish seedlings. On the basis of germination and growth characteristics, vigor index, and relative water content in leaves, it was confirmed that priming treatments with 0.01% ascorbic acid (AA) and 1% KNO3 improves the initial stages of radish development. Furthermore, the efficiency of AA as a priming agent was confirmed through the reduction of malondialdehyde (MDA) level compared to unprimed seedlings. On the other hand, hormopriming with indole-3-acetic acid (IAA) significantly increased the concentration of photosynthetic pigments and total soluble leaf proteins compared to non-primed seedlings. The highest content of total phenolic compounds, including flavonoids, were obtained after hormopriming with 1 mM IAA and halopriming with 1% MgSO4. On the basis of the percentage of inhibition of DPPH radicals, it was confirmed that treatments with IAA and AA can improve the antioxidant activity of radish seedlings. This study provides useful information regarding the possibilities of pregerminative metabolic modulation through the seed priming for the biochemical and physiological improvement of radish, and this topic should be further investigated in order to determine the potential use of AA and IAA as suitable priming agents in radish commercial production.

High Salinity Reduces Plant Growth and Photosynthetic Performance but Enhances Certain Nutritional Quality of C4 Halophyte Portulaca oleracea L. Grown Hydroponically Under LED Lighting.

Portulaca oleracea L. (known as purslane) is one of the most nutritious leafy vegetables owing to its high content of antioxidants. In this study, all plants were grown indoors hydroponically with different NaCl salinities. Photosynthetic photo flux density (PPFD) at 200 μmol m−2 s−1 (12 h) was provided to all plants by LED with red:blue ratio of 2.2. Thirty days after transplanting, plants grown with100 mM NaCl had the highest productivity and the fastest leaf growth followed by those with 0, 200 and 300 mM NaCl. Grown with 300 mM NaCl, purslane had the lowest specific leaf area due to its highest leaf dry matter content and its lowest water content. All plants had similar values of leaf succulence except for those with 300 mM NaCl. Total chlorophyll and carotenoids contents were significantly higher in plants grown with 0 and 100 mM NaCl than with 200, and 300 mM NaCl. All plants had Fv/Fm ratios close to 0.8. However, electron transport rate and ΔF/Fm′ were significantly higher in plants grown with 0 and 100 mM NaCl than with 200 and 300 mM NaCl. CAM-induced purslane with 300 mM NaCl had higher non-photochemical quenching. Maximum net photosynthetic O2 evolution rate and Cyt b6f concentration were significantly lower with 300 mM NaCl compared to all other plants while all plants had similar PS II concentration. Proline concentration increased with increasing salinities. All plants had similar levels of total soluble sugars. Plants grown with 0 and 100 mM NaCl had significantly higher concentrations of NO3−, total reduced nitrogen, total leaf soluble protein, Rubisco protein, total ascorbic acid, and total phenolic compounds than with 200 and 300 mM NaCl. The highest concentrations of K, Ca, and Mg were found in purslane grown under 0 mM NaCl. Statistically, no significant differences in Fe concentrations were observed among all plants. However, salinity seems to increase Fe concentration. In conclusion, it is feasible to grow purslane under 100 mM NaCl as it is the most optimal condition to achieve higher productivity and better quality. However, the production of antioxidants may depend on not only salinity but also other growth conditions.

Genetic parameters estimation and factor analysis of morphological and physiological characteristics of F2:4 rice (Oryza sativa L.) genotypes in germination stage under salinity conditions

IntroductionSalinity stress greatly affects crop yields especially in arid and semi-arid climates. The reaction of rice plants; with a special situation among other crops for supplying human nutrition, to salinity varies in different growth stages. Salinity tolerance in plants is a complex process in which morphological changes, physiological and biochemical processes are involved. In order to study the reaction of rice plants to salinity conditions and identification of tolerant genotypes, it is recommended to evaluate the salinity effects at salinity sensitive stages such as germination stage. The use of genetic diversity in crops is one of the most important interests of breeders in understanding the strategies for crops improvements. The aim of this research was to, estimate the genetic diversity of evaluated traits, study the effect of salinity on various morphological and physiological characteristics in the rice germination stage, determine the relationship between traits, and to identify the traits that affect the indirect selection of tolerant genotypes to salinity. Materials and methodsOne hundred seventeen F2:4 generation lines; obtained from the cross between Mousa Tarom and 304 rice genotypes, were cultured in two separate experiments; with and without salinity stress, in a randomized complete block design at the Faculty of Agriculture, Yasouj University. The seeds were placed in petri dishes in germinator at 25 ± 3 ° C. The number of germinated seeds of each genotype was counted during 14 days, and the seed length and weight vigor, germination percentage, seed germination rate, as well as the morpho- physiological characteristics of rootlet and shootlet length, rootlet fresh and dry weight, shootlet fresh and dry weight, Leaf proline, total soluble sugars and leaf protein content were evaluated. Results and discussionIn both the salinity stress and non-stress conditions, the phenotypic coefficient of variation (CVp) was larger than the genetic coefficient of variation (CVg) for all measured traits. Leaf proline, total protein and soluble sugars had the highest CVg in both the stress and non-stress conditions, indicating a wide diversity of the evaluated genotypes. The genotypes showed the lowest CVg and CVp under both the conditions for germination percentage. So, it can be claimed that the genotypes were not significantly different in their reaction to environmental variations.Proline heritability was 98% in both the salinity conditions. The heritability of protein content in stress condition (86%) was about 13 percentage points lower than non-stress (99%). Salinity stress increased 6 percentage points of soluble sugars (98%) compared to non-stress condition. Salinity stress also increased the heritability of germination percentage, shootlet length, shootlet fresh weight, rootlet fresh weight, and shootlet dry weight and Seedling length vigor index compared to non-stress condition. In non-stress condition, the highest positive and significant correlation was found between rootlet and Seedling length vigor index, and between shootlet dry weight and weight vigor index. In stress conditions, the highest correlation was observed between rootlet length and rootlet dry weight. Also, a significant correlation was observed between the characteristics of the Seedling length vigor index with rootlet dry weight, rootlet and shootlet fresh weight, germination percentage and rate in salinity stress condition. Rootlet dry weight with germination percentage, rootlet length and shootlet length showed a positive and highly significant correlations. No significant correlation was seen between soluble proline, total protein content and soluble sugars in germination stage.On the basis of principal component analysis, in non-stress, and salinity stress conditions 5 and 6 factors were identified, respectively, which explained 74% and 78% of the diversity of the total data. In non-stress conditions, the first factor explained 33.92% of the variation, in that, traits such as shootlet length, shootlet fresh and dry weight and seedling weight vigor index had the highest effect with the positive direction. In stress condition, the first factor explained 32.2% of the total variation in which the shootlet fresh weight and length, germination percentage and germination rate, and Seedling length vigor index had the highest positive effect. ConclusionDifferent lines and varieties of rice show different responses to different environmental stresses, which evaluation of such a reactions are of particular importance for breeders. Leaf soluble proline, protein and soluble sugars had the highest genetic variation in both the stress and non-stress conditions. These conditions indicated that selection for soluble sugars, proline, and leaf total protein was promising, and their high heritability suggests that the traits in question are more likely to be transmitted to the offspring. Therefore, they can be used in breeding programs for creation of genetic diversity, hybridization and selection. Based on the results of factor analysis, shootlet fresh weight and length can be used as an effective feature in the selection of salt tolerant genotypes in both stress and non-stress conditions at germination stage.

Effect of Nitrogen Fertilizers on Yield and Antioxidant Enzymes of Basil (Ocimum basilicum L.) under Water Stress Conditions

Water scarcity in Iran has always been a limiting factor for crop and horticultural production. Under these conditions, the nutrient uptake and metabolism processes of plants are different and can reduce growth. To study water stress (at three levels) and six fertilizer regimes (Nitrogen fertilizer requirement by a combination of vermicompost and urea fertilizer) on the quantitative yield of experimental basil (Ocimum basilicum L.). Results showed that water deficit treatment reduced leaf chlorophyll content, leaf soluble proteins, shoot dry weight and essential oil yield. The highest concentration of total chlorophyll and leaf soluble protein was obtained in normal irrigation and fertilizer regime of 1 ton vermicompost. And water deficit stress reduced these two traits. The lowest activity of antioxidant enzymes was obtained under non-stress conditions. Increasing of water deficit stress increased the activity of these antioxidants among fertilizer treatments. The highest activity of this antioxidant was obtained in non-fertilizer treatment and by adding vermicompost fertilizer to fertilizer treatment of this antioxidant. Forks also declined. The shoot dry weight and essential oil yield decreased under water deficit stress. Increasing vermicompost share in fertilizer treatments led to increased yield. The percentage of essential oil increased with moderate irrigation and decreased again with severe irrigation. In general, the results showed that vermicompost had a positive effect on both vegetative and physiological traits of the plant. Keywords: Catalase, Compost, Peroxidase, Secondary metabolites, Urea fertilizer DOI: 10.7176/JSTR/5-11-12

Potent insect gut binding lectin from Sclerotium rolfsii impart resistance to sucking and chewing type insects in cotton

Cotton is an important crop that is continuously cultivated around the world. However, its production has decreased in recent times due to wide ranging insects and also current practices of using synthetic insecticides that are not precise and their residues impairing the biodiversity. Hence, the search for newer classes of efficient entomotoxic proteins continues. Genetically modified cotton crops with cry genes from Bacillus thuringiensis, have been cultivated across the world, which overcome the chewing type insect menace. In the present study, we assess the development of transgenic cotton plants by Agrobacterium, wherein the confirmed kanamycin resistant T0 plants were advanced to T1 generation and the gene integration was studied by molecular analysis. Western blot and ELISA assays demonstrated the expression of 0.46% lectin of the total soluble leaf proteins. In planta bioassay showed 69% of aphid, Aphis gossypii population reduction with T1 generation plants. Whereas 100% insect mortality is occurred in Spodoptera litura larvae by 96 h. Present findings shows the potent insecticidal effect of Sclerotium rolfsii lectin on sucking (homopteran) and chewing (lepidopteron) insects, underlining its significance and strengthening genetic resources in cotton breeding against different order insect pests.

Biologically active recombinant human erythropoietin expressed in hairy root cultures and regenerated plantlets of Nicotiana tabacum L.

Hairy root culture is a potential alternative to conventional mammalian cell culture to produce recombinant proteins due to its ease in protein recovery, low costs and absence of potentially human pathogenic contaminants. The current study focussed to develop a new platform of a hairy root culture system from Nicotiana tabacum for the production of recombinant human EPO (rhEPO), which is regularly produced in mammalian cells. The human EPO construct was amplified with C-terminal hexahistidine tag from a cDNA of Caco-2 cells. Two versions of rhEPO clones, with or without the N-terminal calreticulin (cal) fusion sequence, were produced by cloning the amplified construct into gateway binary vector pK7WG2D. Following Agrobacterium rhizogenes mediated transformation of tobacco explants; integration and expression of constructs in hairy roots were confirmed by several tests at DNA, RNA and protein levels. The amount of intracellular rhEPO from hairy root cultures with cal signal peptide was measured up to 66.75 ng g-1 of total soluble protein. The presence of the ER signal peptide (cal) was essential for the secretion of rhEPO into the spent medium; no protein was detected from hairy root cultures without ER signal peptide. The addition of polyvinylpyrrolidone enhanced the stabilization of secreted rhEPO leading to a 5.6 fold increase to a maximum concentration of 185.48 pg rhEPOHR g-1 FW hairy root cultures. The rhizo-secreted rhEPO was separated by HPLC and its biological activity was confirmed by testing distinct parameters for proliferation and survival in retinal pigment epithelial cells (ARPE). In addition, the rhEPO was detected to an amount 14.8 ng g-1 of total soluble leaf protein in transgenic T0 generation plantlets regenerated from hairy root cultures with cal signal peptide.

Expression of an insecticidal fern protein in cotton protects against whitefly.

Whitefly (Bemisia tabaci) damages field crops by sucking sap and transmitting viral diseases. None of the insecticidal proteins used in genetically modified (GM) crop plants to date are effective against whitefly. We report the identification of a protein (Tma12) from an edible fern, Tectaria macrodonta (Fee) C. Chr., that is insecticidal to whitefly (median lethal concentration = 1.49 μg/ml in in vitro feeding assays) and interferes with its life cycle at sublethal doses. Transgenic cotton lines that express Tma12 at ∼0.01% of total soluble leaf protein were resistant to whitefly infestation in contained field trials, with no detectable yield penalty. The transgenic cotton lines were also protected from whitefly-borne cotton leaf curl viral disease. Rats fed Tma12 showed no detectable histological or biochemical changes, and this, together with the predicted absence of allergenic domains in Tma12, indicates that Tma12 might be well suited for deployment in GM crops to control whitefly and the viruses it carries.

A Fusion between Domains of the Human Bone Morphogenetic Protein-2 and Maize 27 kD γ-Zein Accumulates to High Levels in the Endoplasmic Reticulum without Forming Protein Bodies in Transgenic Tobacco.

Human Bone Morphogenetic Protein-2 (hBMP2) is an osteoinductive agent physiologically involved in bone remodeling processes. A commercialized recombinant hBMP2 produced in mammalian cell lines is available in different clinical applications where bone regeneration is needed, but widespread use has been hindered due to an unfavorable cost/effective ratio. Protein bodies are very large insoluble protein polymers that originate within the endoplasmic reticulum by prolamine accumulation during the cereal seed development. The N-terminal domain of the maize prolamin 27 kD γ-zein is able to promote protein body biogenesis when fused to other proteins. To produce high yield of recombinant hBMP2 active domain (ad) in stably transformed tobacco plants we have fused it to the γ-zein domain. We show that this zein-hBMP2ad fusion is retained in the endoplasmic reticulum without forming insoluble protein bodies. The accumulation levels are above 1% of total soluble leaf proteins, indicating that it could be a rapid and suitable strategy to produce hBMP2ad at affordable costs.

Expression, subcellular localization, and enzyme activity of a recombinant human extra-cellular superoxide dismutase in tobacco (Nicotiana benthamiana L.)

Human extracellular superoxide dismutase (hEC-SOD) is an enzyme that scavenges reactive oxygen species (ROS). Because of its antioxidant activity, hEC-SOD has been used as a therapeutic protein to treat skin disease and arthritis in mammalian systems. In this study, codon-optimized hEC-SOD was expressed in tobacco (Nicotiana benthamiana L.) via a plant-based transient protein expression system. Plant expression binary vectors containing full-length hEC-SOD (f-hEC-SOD) and modified hEC-SOD (m-hEC-SOD), in which the signal peptide and heparin-binding domain were deleted, were constructed for the cytosolic-, endoplasmic reticulum (ER)-, and chloroplast-localizations in tobacco leaf mesophyll cells. The results demonstrated that f-hEC-SOD was more efficiently expressed in the cytosolic fractions than in the ER or chloroplasts of tobacco cells. Our data further indicated that differently localized f-hEC-SOD and m-hEC-SOD displayed SOD enzyme activities, suggesting that the hEC-SODs expressed by plants may be functionally active. The f-hEC-SOD was expressed up to 3.8% of the total leaf soluble protein and the expression yield was calculated to be 313.7 μg f-hEC-SOD per g fresh weight of leaf. Overall, our results reveal that it was possible to express catalytically active hEC-SODs by means of a transient plant expression system in tobacco leaf cells.

Characterization of the rice RbcS3 promoter and its transit peptide for use in chloroplast-targeted expression

Here, we report characterization of an RbcS promoter and its transit peptide for use in chloroplast-targeted expression. RbcS3 that encodes a small subunit of ribulose bisphosphate carboxylase/oxygenase is of great interest due to its green tissue-specific expression such as leaf and leaf sheaths. We isolated the RbcS3 promoter and its transit peptide sequence and linked to GFP for characterization in transgenic plants. Our qRT-PCR analysis on leaves and roots of transgenic plants revealed that GFP transcript levels were higher by fivefold in leaves of RbcS3:TP3:GFP transgenic lines than in those of the RbcS3:GFP transgenic lines, suggesting that the transcript levels were increased by chloroplast-targeted expression, as shown in previously characterized RbcS1:TP1 system. The transit peptide sequence TP3 was sufficient to target GFP to chloroplasts as observed in protoplasts of RbcS3:TP3:GFP transgenic lines. GFP fluorescence in RbcS3:GFP plants was detected only in the cytosol. The GFP protein levels in leaves of RbcS3:TP3:GFP plants were 0.12–0.23 % of the total soluble leaf proteins. These levels were higher or comparable to those of PGD1:GFP plants (GFP driven by a constitutive promoter PGD1). Taken together, these results indicate that the fusion of the RbcS3 promoter to its transit peptide, RbcS3:TP3, provides a chloroplast-targeting expression system.

Sclerotium rolfsii lectin expressed in tobacco confers protection against Spodoptera litura and Myzus persicae

Bacillus thuringiensis (Bt) toxins expressed in GM crops provide effective protection against chewing-type insects but fail to control damage by sucking pests, leading to a search for a newer class of efficient entomotoxic proteins. In this direction lectins with novel sugar-binding properties showing toxicity to a wide range of agricultural insect pests are being evaluated for the insecticidal efficacy. Our previous study demonstrated the potential toxic effect of O-glycans sugar-specific Sclerotium rolfsii lectin (SRL) supplemented through an artificial diet on the growth and survival of Spodoptera litura larvae by binding to midgut epithelial cells. Considering the significance of its entomotoxic property, we cloned the SRL gene and expressed it in a prokaryotic host, which showed 97 % sequence homology to the native SRL. Recombinant SRL (recSRL) exhibited a carbohydrate-binding property and insecticidal activity similar to native SRL. The SRL gene was transferred into tobacco plants by Agrobacterium-mediated transformation and expressed constitutively using a CaMV35S promoter. Integration and stability of the SRL gene was confirmed by Southern hybridization. recSRL expressed in the transgenic tobacco leaves was analyzed by Western blotting and quantified by ELISA, which accounted for 0.47 % of the total soluble leaf proteins. Bioassays conducted on second instar S. litura larvae fed on transgenic tobacco leaves showed 90 % larval mortality in 48 h and in planta assays using M. persicae demonstrated an 81.90 % population reduction. These findings indicated that the ectopically expressed SRL conferred protection against target pests of lepidopteran and hemipteran orders.

Novel expression system for enhanced synthesis of antimicrobial peptide cecropin P1 in plants

A gene of antimicrobial peptide cecropin P1 (CP1) was inserted into the vector plasmid pPCV91 under the control of promoter 35S RNA of cauliflower mosaic virus (CaMV 35S) containing four enhancer sequences CaMV 35S and nontranslated leader sequence Ω RNA of tobacco mosaic virus. The recombinant vector obtained was used for agrobacterial transformation of tobacco plants (Nicotiana tabacum L., variety Samsun) with the polymerase chain reaction (PCR)-based method. The presence of gene CP1 in the genome of plants was proven by western-blot analysis and testing the antibiotic activity of plant extracts. In different plant lines, the level of cecropin P1 synthesis amounted 0.02–0.2% of total soluble plant leaf protein. The transgenic plants, unlike the control ones, displayed enhanced tolerance to phytopathogenic microorganisms and oxidative stress. It was established that the ability of the transgenic plants to express cecropin P1 is transmitted to progeny.

The intrinsically disordered protein LEA7 from Arabidopsis thaliana protects the isolated enzyme lactate dehydrogenase and enzymes in a soluble leaf proteome during freezing and drying

The accumulation of Late Embryogenesis Abundant (LEA) proteins in plants is associated with tolerance against stresses such as freezing and desiccation. Two main functions have been attributed to LEA proteins: membrane stabilization and enzyme protection. We have hypothesized previously that LEA7 from Arabidopsis thaliana may stabilize membranes because it interacts with liposomes in the dry state. Here we show that LEA7, contrary to this expectation, did not stabilize liposomes during drying and rehydration. Instead, it partially preserved the activity of the enzyme lactate dehydrogenase (LDH) during drying and freezing. Fourier-transform infrared (FTIR) spectroscopy showed no evidence of aggregation of LDH in the dry or rehydrated state under conditions that lead to complete loss of activity. To approximate the complex influence of intracellular conditions on the protective effects of a LEA protein in a convenient in-vitro assay, we measured the activity of two Arabidopsis enzymes (glucose-6-P dehydrogenase and ADP-glucose pyrophosphorylase) in total soluble leaf protein extract (Arabidopsis soluble proteome, ASP) after drying and rehydration or freezing and thawing. LEA7 partially preserved the activity of both enzymes under these conditions, suggesting its role as an enzyme protectant in vivo. Further FTIR analyses indicated the partial reversibility of protein aggregation in the dry ASP during rehydration. Similarly, aggregation in the dry ASP was strongly reduced by LEA7. In addition, mixtures of LEA7 with sucrose or verbascose reduced aggregation more than the single additives, presumably through the effects of the protein on the H-bonding network of the sugar glasses.

TiO2 nanoparticle biosynthesis and its physiological effect on mung bean (Vigna radiata L.)

TiO2 nanoparticle (NPs) biosynthesis is a low cost, ecofriendly approach developed using the fungi Aspergillus flavus TFR 7. To determine whether TiO2 NPs is suitable for nutrient, we conducted a two part study; biosynthesis of TiO2 NP and evaluates their influence on mung bean. The characterized TiO2 NPs were foliar sprayed at 10mgL−1 concentration on the leaves of 14 days old mung bean plants. A significant improvement was observed in shoot length (17.02%), root length (49.6%), root area (43%), root nodule (67.5%), chlorophyll content (46.4%) and total soluble leaf protein (94%) as a result of TiO2 NPs application. In the rhizosphere microbial population increased by 21.4–48.1% and activity of acid phosphatase (67.3%), alkaline phosphatase (72%), phytase (64%) and dehydrogenase (108.7%) enzyme was observed over control in six weeks old plants owing to application of TiO2 NPs. A possible mechanism has also been hypothesized for TiO2 NPs biosynthesis.

Development of Zinc Nanofertilizer to Enhance Crop Production in Pearl Millet (Pennisetum americanum)

In context to environmentally benign technology, present study was made for biosynthesis of zinc nanoparticles which were used as nanofertilizer to enhance crop production in pearl millet (Pennisetum americanum L.) cv. HHB 67. Synthesized zinc nanoparticles were characterized for confirmation of size, shape, surface structure, crystalline nature, and study of elemental proportion. Results indicate that synthesized nanoparticle size ranged between 15 and 25 nm. A significant improvement in shoot length (15.1 %), root length (4.2 %), root area (24.2 %), chlorophyll content (24.4 %), total soluble leaf protein (38.7 %), plant dry biomass (12.5 %), and enzyme activities of acid phosphatase (76.9 %), alkaline phosphatase (61.7 %), phytase (322.2 %), and dehydrogenase (21 %) were observed over control in 6 weeks old plants. The grain yield at crop maturity was improved by 37.7 % due to application of zinc nanofertilizer.

Effect of Boron on the Contents of Chlorophyll, Carotenoid, Phenol and Soluble Leaf Protein in Mung Bean, Vigna radiata (L.) Wilczek

Greenhouse experiments were carried out to study the effect of boron (B) on certain biochemical constituents considering mung bean, Vigna radiata (L.) Wilczek as an experimental crop. B as boric acid (H3BO3) was applied at the concentrations of 0, 1, 2, 4, 8, 16 and 32 μg B g−1 soil. Lower applied doses of B up to 4 μg g−1 resulted in an increase in chlorophyll and carotenoid contents and decrease in stress indicators viz. total phenol content and soluble leaf protein content. Maximum increment in chlorophyll and carotenoid contents was observed at 4 μg g−1 B concentrations, while at this concentration (4 μg g−1) maximum decrease in total phenol content and soluble leaf protein content was observed. Reciprocal relationship between total chlorophyll contents and total phenol content was observed. Adverse effect on selected biochemical constituents beyond 4 μg g−1 B concentrations reflected the importance of efficient and appropriate use of boron in agronomic practices for mung bean.

Root-zone CO<sub>2</sub> and root-zone temperature effects on photosynthesis and nitrogen metabolism of aeroponically grown lettuce (Lactuca sativa L.) in the tropics

Effects of elevated root-zone (RZ) CO2 concentration (RZ [CO2]) and RZ temperature (RZT) on photosynthesis, productivity, nitrate (NO3 −), total reduced nitrogen (TRN), total leaf soluble and Rubisco proteins were studied in aeroponically grown lettuce plants in a tropical greenhouse. Three weeks after transplanting, four different RZ [CO2] concentrations (ambient, 360 ppm, and elevated concentrations of 2,000; 10,000; and 50,000 ppm) were imposed on plants at 20°C-RZT or ambient(A)-RZT (24–38°C). Elevated RZ [CO2] resulted in significantly higher light-saturated net photosynthetic rate, but lower light-saturated stomatal conductance. Higher elevated RZ [CO2] also protected plants from both chronic and dynamic photoinhibition (measured by chlorophyll fluorescence Fv/Fm ratio) and reduced leaf water loss. Under each RZ [CO2], all these variables were significantly higher in 20°C-RZT plants than in A-RZT plants. All plants accumulated more biomass at elevated RZ [CO2] than at ambient RZ [CO2]. Greater increases of biomass in roots than in shoots were manifested by lower shoot/root ratios at elevated RZ [CO2]. Although the total biomass was higher at 20°C-RZT, the increase in biomass under elevated RZ [CO2] was greater at A-RZT. Shoot NO3 − and TRN concentrations, total leaf soluble and Rubisco protein concentrations were higher in all elevated RZ [CO2] plants than in plants under ambient RZ [CO2] at both RZTs. Under each RZ [CO2], total leaf soluble and Rubisco protein concentrations were significantly higher at 20°C-RZT than at A-RZT. Our results demonstrated that increased P Nmax and productivity under elevated [CO2] was partially due to the alleviation of midday water loss, both dynamic and chronic photoinhibition as well as higher turnover of Calvin cycle with higher Rubisco proteins.

ZnO Nanoparticle Biosynthesis and Its Effect on Phosphorous-Mobilizing Enzyme Secretion and Gum Contents in Clusterbean (Cyamopsis tetragonoloba L.)

Biological synthesis of ZnO nanoparticle is a new approach for environmentally benign protocol in context to green nanotechnology. In present investigation, ZnO nanoparticles were synthesized from ZnNO3 using extracellular secretions of Aspergillus fumigatus TFR-8 (NCBI GenBank Accession No. JQ675291) and effect of these biologically transformed ZnO nanoparticles was studied on clusterbean (Cyamopsis tetragonoloba L.) to enhance native phosphorous-mobilizing enzymes and nanoinduced gum production. Valid characterization techniques were employed for confirmation of size, shape, surface structure, crystalline nature, and elemental proportion. Results indicate that synthesized nanoparticle size ranging between 1.2 and 6.8 nm at least in one dimension with oblate spherical and hexagonal in structure. The samples contained 98 % atom of Zn element. The characterized ZnO nanoparticles were foliar sprayed at 10 ppm concentration on leaf of 14-day-old clusterbean plants. A significant improvement in plant biomass (27.1 %), shoot length (31.5 %), root length (66.3 %), root area (73.5 %), chlorophyll content (276.2 %), total soluble leaf protein (27.1 %), rhizospheric microbial population (11–14 %), acid phosphatase (73.5 %), alkaline phosphatase (48.7 %), and phytase (72.4 %) activity in clusterbean rhizosphere was observed over control in 6-week-old plants due to application of nanoZnO. The gum content in clusterbean seeds improved by 7.5 % after maturity which indicates ZnO in nano form may contribute more in industrial and medical applications besides agricultural sector. A possible hypothesis of mechanism for ZnO nanoparticle biosynthesis has also been made.

High-level expression of modified gene encoding human adiponectin in transgenic rice.

Adiponectin is a polypeptide specifically secreted from human adipocytes, and its deficiency is closely linked to increased obesity and type II diabetes. There is an urgent demand for large-scale production of human adiponectin for pharmaceutical applications. Here, we report that we have successfully obtained a high-level of expression of modified genes encoding human adiponectin in transgenic rice. The 735 bp cDNA of the native human sequence was adopted to rice codon usage, fused to the translation initiation sequence in the N terminus and to the KDEL signal sequence in the C terminus. An amplification promoting sequence acting as an enhancer of transcription was also introduced to enhance gene expression. The presence of the transgene and mRNA transcripts was confirmed by PCR, Southern blot and RT-PCR. Western blot analysis revealed that a protein of approximately 30 kDa was produced in rice leaves. ELISA analysis was used to determine the amount of recombinant adiponectin in transformants with the modified gene in up to 0.32% of total soluble leaf protein. Our results establish the feasibility of high-level expression of recombinant human adiponectin in transgenic rice.