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The biomolecule-coated nanotitania catalysts were synthesised using rhizome extract of Gloriosa superba and the characteristics of the synthesised nanocatalysts were investigated by using various physiochemical methodologies. The antibacterial activity of the biomolecule coated nanotitania catalysts was tested against harmful microbial human pathogens. Nanotitania catalysts were found to be the most potential agent against gram negative bacterium i.e. Staphylococcus epidermidis. An efficient anti-biofilm activity was also observed against biofilm developing bacteria namely S. epidermidis and Pseudomonas aeruginosa. The 50% inhibitory concentration (IC50) of nanotitania catalysts noticed was 46.64 and 61.81 µg/mL for MCF-7 (cancer) L929 (normal) cell lines, respectively. Bioengineered nanotitania catalysts exhibited potential anticancer activity against breast cancer cell line. AO/EtBr staining results show distinct morphological variations such as orange and red coloured apoptotic bodies were identified in cancer cells that were treated with nanotitania catalysts. Further, the nuclear changes, mitochondrial depolarization and increased reactive oxygen species (ROS) level were also detected in nanotitania catalysts treated MCF-7 cells by Hoechst, rhodamine and DCFH-DA probe staining techniques. COMET assay confirmed the DNA destruction in the nanotitania treated cancer cells. In addition, the nanotitania catalysts exhibited potential photocatalytic activity against inorganic toxic dyes and the maximum rate of dye degradation was observed for crystal violet. The present results strongly suggest that the biomolecule coated nanotitania catalysts could be used as potential and novel compound towards biomedical as well as photocatalytic applications.

Soil salinity and water-deficit conditions often affect crop productivity in groundnut. Therefore, developing transgenic groundnut that can grow under such abiotic stress conditions is crucial to stabilize its yield. Sodium proton antiporter-like protein (NHXLP) is a plasma membrane-bound protein associated with Na+ exclusion and helps to maintain ion homeostasis under saline conditions. In the present study, salt tolerant transgenic groundnut variety JL-24 was developed by expressing SbNHXLP gene isolated from Sorghum bicolor. Molecular analysis of transgenics by PCR and Southern blot confirmed the integration of SbNHXLP gene. SbNHXLP expression at the transcript level was checked by reverse transcriptase (RT)-PCR. Homozygous T2 lines along with wild-type (WT) plants were evaluated for 150 mM NaCl stress tolerance. Biochemical analysis of transgenics under salt stress revealed higher chlorophyll content, superoxide dismutase, and catalase activities, accumulation of proline, and K+ accompanied by lower Na+ accumulation compared to WT plants. Additionally, transgenics displayed higher biomass and pod yield when compared with WT plants under stress. Our findings indicate that overexpression of SbNHXLP gene in groundnut results in enhanced tolerance to salinity stress. This highlights the potential of SbNHXLP as a target candidate gene to impart salt stress tolerance in groundnut. A sodium proton antiporter-like protein isolated from Sorghum (SbNHXLP) was overexpressed in groundnut and stably integrated. Transgenics displayed higher chlorophyll, proline, K+, and better yields than WT plants under salt stress.

Coronavirus disease 2019 (COVID-19) is caused by a Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2), which is a positive-strand RNA virus. The SARS-CoV-2 genome and its association to SAR-CoV-1 vary from ca. 66 to 96% depending on the type of betacoronavirideae family members. With several drugs, viz. chloroquine, hydroxychloroquine, ivermectin, artemisinin, remdesivir, azithromycin considered for clinical trials, there has been an inherent need to find distinctive antiviral mechanisms of these drugs. Curcumin, a natural bioactive molecule has been shown to have therapeutic potential for various diseases, and its effect on COVID-19 is also currently being explored. In this study, we show the binding potential of curcumin targeted to a variety of SARS-CoV-2 proteins, viz. spike glycoproteins (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), spike protein-ACE2 (PDB ID: 6M17) along with nsp10 (PDB ID: 6W4H) and RNA dependent RNA polymerase (PDB ID: 6M71) structures. Furthermore, representative docking complexes were validated using molecular dynamics simulations and mechanistic studies at 100 ns was carried on nucleocapsid and nsp10 proteins with curcumin complexes which resulted in stable and efficient binding energies and correlated with that of docked binding energies of the complexes. Both the docking and simulation studies indicate that curcumin has the potential as an antiviral against COVID-19.

Lysine (Lys) is indispensable nutritionally, and its levels in plants are modulated by both transcriptional and post-transcriptional control during plant ontogeny. Animal glutamate receptor homologs have been detected in plants, which may participate in several plant processes through the Lys catabolic products. Interestingly, a connection between Lys and serotonin metabolism has been established recently in rice. 2-Aminoadipate, a catabolic product of Lys appears to play a critical role between serotonin accumulation and the color of rice endosperm/grain. It has also been shown that expression of some lysine-methylated proteins and genes encoding lysine-methyltransferases (KMTs) are regulated by cadmium even as it is known that Lys biosynthesis and its degradation are modulated by novel mechanisms. Three complex pathways co-exist in plants for serine (Ser) biosynthesis, and the relative preponderance of each pathway in relation to plant development or abiotic stress tolerance are being unfolded slowly. But the phosphorylated pathway of L-Ser biosynthesis (PPSB) appears to play critical roles and is essential in plant metabolism and development. Ser, which participates indirectly in purine and pyrimidine biosynthesis and plays a pivotal role in plant metabolism and signaling. Also, L-Ser has been implicated in plant responses to both biotic and abiotic stresses. A large body of information implicates Lys-rich and serine/arginine-rich (SR) proteins in a very wide array of abiotic stresses. Interestingly, a link exists between Lys-rich K-segment and stress tolerance levels. It is of interest to note that abiotic stresses largely influence the expression patterns of SR proteins and also the alternative splicing (AS) patterns. We have checked if any lncRNAs form a cohort of differentially expressed genes from the publicly available PPSB, sequence read archives of NCBI GenBank. Finally, we discuss the link between Lys and Ser synthesis, catabolism, Lys-proteins, and SR proteins during plant development and their myriad roles in response to abiotic stresses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease2019 (COVID-19). SARS-CoV-2 is known for its high pathogenicity and transmission due to thepresence of polybasic cleavage sites. No specific drug is available for the treatment. To identifythe potential inhibitors, we have performed molecular docking against the SARS-CoV-2 mainprotease (6Y84) with fifteen important natural xanthone compounds. The docking results showedall the compounds exhibited good binding energies and interactions with the main protease. Thevalidation of representative docking complexes through molecular dynamics simulations showedthat xanthones binds with a higher binding affinity and lower free energy than the standardligand with Brasixanthone C and Brasixanthone B on 50 ns. Natural xanthone compounds havealso passed the Absorption, Distribution, Metabolism, and Excretion (ADME) property criteriaas well as Lipinski’s rule of five. The present integrated molecular docking and dynamicssimulations study unveil the use of xanthones as potential antiviral agents against SARS-CoV-2.

The Cucurbita genus, often called as cucurbits, include several economically important fruits and vegetable crops like cucumber, gourds, squash, watermelon, pumpkin, and melon. Several of the species including Cucurbita pepo and C. maxima have nutritional value and are utilized in folk medicine for treating gastrointestinal diseases and intestinal parasites. Such an activity is attributed to the presence of fatty acids, glycosides, resins, sterols, carotenoids, phenols, tocopherols, saponins, steroids, and terpenoids such as cucurbitacins. Squash and pumpkin are the major members of Cucurbitaceae family used as food and animal feed. The two major pumpkin varieties C. pepo and C. maxima are considered as highly polymorphic with manifold nutritional, including food preservative abilities and medicinal activities. Development of transgenic pepo for tolerance to various biotic and abiotic stresses coupled with nutritional value is the need of the hour. Very few reports are available on transgenic production of pepo. The present review summarizes the regeneration and transformation protocols for developing transgenic C. pepo and C. maxima and future prospects.

Pearl millet is an important crop for alleviating micronutrient malnutrition through genomics-assisted breeding for grain Fe (GFeC) and Zn (GZnC) content. In this study, we identified candidate genes related to iron (Fe) and zinc (Zn) metabolism through gene expression analysis and correlated it with known QTL regions for GFeC/GZnC. From a total of 114 Fe and Zn metabolism-related genes that were selected from the related crop species, we studied 29 genes. Different developmental stages exhibited tissue and stage-specific expressions for Fe and Zn metabolism genes in parents contrasting for GFeC and GZnC. Results revealed that PglZIP, PglNRAMP and PglFER gene families were candidates for GFeC and GZnC. Ferritin-like gene, PglFER1 may be the potential candidate gene for GFeC. Promoter analysis revealed Fe and Zn deficiency, hormone, metal-responsive, and salt-regulated elements. Genomic regions underlying GFeC and GZnC were validated by annotating major QTL regions for grain Fe and Zn. Interestingly, PglZIP and PglNRAMP gene families were found common with a previously reported linkage group 7 major QTL region for GFeC and GZnC. The study provides insights into the foundation for functional dissection of different Fe and Zn metabolism genes homologs and their subsequent use in pearl millet molecular breeding programs globally.

Key message The HbCAld5H1 gene cloned from Hevea brasiliensis regulates the cambial activity, xylem differentiation, syringyl–guaiacyl ratio, secondary wall structure, lignification pattern and xylan distribution in xylem fibres of transgenic tobacco plants. Abstract Molecular characterization of lignin biosynthesis gene coniferaldehyde-5-hydroxylase (CAld5H) from Hevea brasiliensis and its functional validation was performed. Both sense and antisense constructs of HbCAld5H1 gene were introduced into tobacco through Agrobacterium-mediated genetic transformation for over expression and down-regulation of this key enzyme to understand its role affecting structural and cell wall chemistry. The anatomical studies of transgenic tobacco plants revealed the increase of cambial activity leading to xylogenesis in sense lines and considerable reduction in antisense lines. The ultra-structural studies showed that the thickness of secondary wall (S2 layer) of fibre had been decreased with non-homogenous lignin distribution in antisense lines, while sense lines showed an increase in S2 layer thickness. Maule color reaction revealed that syringyl lignin distribution in the xylem elements was increased in sense and decreased in antisense lines. The immunoelectron microscopy revealed a reduction in LM 10 and LM 11 labelling in the secondary wall of antisense tobacco lines. Biochemical studies showed a radical increase in syringyl lignin in sense lines without any significant change in total lignin content, while S/G ratio decreased considerably in antisense lines. Our results suggest that CAld5H gene plays an important role in xylogenesis stages such as cambial cell division, secondary wall thickness, xylan and syringyl lignin distribution in tobacco. Therefore, CAld5H gene could be considered as a promising target for lignin modification essential for timber quality improvement in rubber.

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is a respiratory syndrome caused by positive RNA virus resulting in outbreak of corona virus disease 2019 (COVID-19). The SARS-CoV-2 genome and its association to SAR-CoV-1 vary from ca. 66% to 96% depending on the type of betacoronavirdeae family members. With several drugs, viz. chloroquine, hydroxychloroquine, ivermectin, quinidine, artemisinin, remdesivir, azithromycin considered for clinical trials, there has been an inherent need to find distinctive antiviral mechanisms of these drugs. On the other hand, curcumin, a natural bioactive molecule has been shown to have a therapeutic potential for various diseases, but no role of it in COVID-19 has been explored. In this work, we show the binding potential of curcumin targeted to a host of SARS-CoV-2 proteins, viz. spike glycoproteins (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17) along with nsp10 (PDB ID: 6W4H) and RNA dependent RNA polymerase (PDB ID: 6M71) structures. Our results indicate that curcumin has potential antiviral protein binding affinity towards SARS-CoV-2 proteins which is comparable with other repurposed drugs that are considered for clinical trials.

Sorghum is a major staple globally and biofortifying sorghum with increased grain iron and zinc complements ongoing efforts to combat micronutrient malnutrition. Limited information available on the nature and magnitude of gene effects for grain iron and zinc. So generation mean analysis was done using four crosses, ICSB 52 × IS 13211, ICSB 52 × SPV 1359, IS 20843 × IS 2248 and IS 2248 × IS 20843. Six generations, P1, P2, F1, F2, B1 and B2, were generated for each of these crosses which were evaluated during the postrainy season 2012–13. The mean sum of squares due to generations were significant for days to flowering, plant height, grain yield/plant, 100-grain weight, and grain Fe and Zn. Generation mean studies revealed the presence of both additive and dominant gene interactions in inheritance of agronomic traits. Duplicative epistasis was observed for days to flowering, plant height, grain yield/plant, 100-grain weight, and grain Zn with a predominance of dominant gene action in inheritance of these traits. Panicle length, panicle width, and grain Fe showed both additive and dominance gene effects, with higher magnitude of dominance. This information can be utilized in developing sorghum lines with high grain Fe and Zn.

Plants overcome the effect of Na+ toxicity either by excluding Na+ at the plasma membrane or by sequestering them into the vacuoles. Influx of Na+ ions into the plant vacuoles is usually driven by H+ generated by vacuolar-type H+-ATPase as well as vacuolar proton pyrophosphatse (VPPase). In the present study, we have developed Bacopa monnieri transgenics via Agrobacterium tumefaciens containing the recombinant vector pCAMBIA2300-SbVPPase gene. Transformants were produced using nodal explants. Transformants were confirmed by PCR and DNA blot analysis. qPCR analysis showed higher transcript levels of SbVPPase compared to untransformed control (UC). Higher VPPase activity was recorded in transgenics compared to UC. Under 150 mM salt stress, transgenic shoots showed enhanced Na+ accumulation with better biomass production, increased glycine betaine content, and total soluble sugar levels than UC. Transgenic shoots showed 2.9–3.8-folds lower levels of malondialdehyde content indicating lesser membrane damage. Increase in antioxidant enzyme activities (1.4–3.2-folds) was observed in transgenics compared to UC. Transgenics also displayed 7.3–9.0-folds enhanced accumulation of the medicinally important compound bacoside A. Increased biomass production, accumulation of Na+, osmolytes (glycine betaine, sugars etc.), and elevated antioxidant enzyme activities indicate better osmotic adjustment in transgenics by compartmentalization of Na+ into the vacuoles under salt stress conditions. Thus, overexpression of SbVPPase in Bacopa alleviated salt stress by sequestering Na+.

Morphogenic cultures of Gloriosa superba were initiated on Murashige and Skoog’s medium fortified with 2 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5 mg L−1 naphthaleneacetic acid (NAA), 4% sucrose and 0.1% activated charcoal. To enhance the content of the alkaloid colchicine, morphogenic cultures were treated with different concentrations of abiotic elicitors like signalling compounds, metals, biotic elicitors, precursors and a combination of elicitors. Signalling molecules like acetyl salicylic acid (ASA) and sodium nitroprusside improved the production of colchicine. Abiotic elicitors have markedly (p ≤ 0.05 or ≤ 0.01) enhanced the colchicine content either at lower or higher concentrations. Among the metals, the highest amount of 11.67 mg of colchicine g−1 dry wt was noticed at 60 mM rubidium chloride, followed by 60 mM NaCl (11.18 mg g−1). Contrarily, in the presence of biotic elicitors such as Fusarium oxysporum, Alternaria solani, and Saccharomyces cerevisiae, colchicine content ranged only between 2 and 5.32 mg g−1, but Bacillus subtilis repressed it. Among the aromatic amino acids, phenylalanine at 500 mg L−1 influenced the highest accumulation of 19.48 mg g−1 dry tissue, followed by tryptophan (12.47 mg g−1), and tyrosine (9.87 mg g−1), a direct precursor of colchicine biosynthesis, while intact tubers and leaves contained 4.65 and 4.16 mg of colchicine g−1 dry tissue respectively. A combination of 10 µM AlCl3 and 50 µM salicylic acid (SA) registered 17.34 mg g−1 followed by 16.24 mg g−1 tissue in presence of 1 µM HgCl2 and 50 µM SA. The results suggest that the elicitor-stimulated colchicine accumulation was a stress response and can be exploited further for commercial production.

Dehydrins (DHNs) are highly hydrophilic, thermo stable, calcium dependent chaperons involved in plant developmental processes as well as in diverse abiotic stresses. A systematic survey resulted in the identification of 7 dehydrins (DHNs) in Setaria italica and Zea mays, but 6 in Sorghum bicolor. They are classified into 5 sub-groups, namely YnSKn, SKn, KnS, S, and YnS. DHNs of Sorghum exhibit 1 ortholog with Oryza sativa and Z. mays and 3 with S. italica. Unlike other DHNs, SbDHN5 has been found as an ordered protein with many phosphorylation sites. Network analyses of novel YnS subgroup showed interaction with HSP70 and FKBP genes. In silico promoter analysis revealed the presence of abscisic acid (ABA), drought, salt, low temperature stress-responsive elements. The miRNA target analysis revealed DHNs are targeted by 51 miRNAs responsive to abiotic stresses. High transcript expressions of DHNs were observed in root, stem and leaf compared to inflorescence in S. bicolor. All DHN genes exhibited high levels of expression in stem under cold, heat, salt, and drought stresses. In contrast to other DHNs, the SbDHN2 of YnS subgroup, exhibited the highest expression, under multiple stresses in all the tissues indicating its involvement against a wide array of abiotic stresses.

An efficient protocol for somatic embryogenesis and plant regeneration from rhizome explants of Gloriosa superba L. was developed using various plant growth regulators (PGRs), Ulva lactuca extracts (ULE), and phycomolecule-coated U. lactuca silver nanoparticles (ULAgNPs). Callus was initiated from rhizome explants on the Murashige and Skoog (MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (1.0–5.0 mg L−1), α-naphthaleneacetic acid (NAA) (0.5 mg L−1), ULE (10–50%), and ULAgNPs (0.1–0.5 mg L−1). Callus was cultured on MS medium fortified with various concentrations and combinations of 6-benzylaminopurine (BAP) (0.5–2.5 mg L−1), kinetin (KIN) (0.5–2.5 mg L−1), ULAgNPs (0.1–0.5 mg L−1), and 20% ULE along with 0.5 mg L−1 NAA for the development of somatic embryos (SEs). The maximum percentage of embryo maturation (100%) was observed on the medium containing 0.5 mg L−1 ULAgNPs, 2.0 mg L−1 BAP, 0.5 mg L−1 abscisic acid (ABA), 0.5 mg L−1 silver nitrate (AgNO3), and 20% ULE. The highest percentage of embryo germination (86.1%) was noticed on the MS medium containing 0.3 mg L−1 ULAgNPs, 5.0 mg L−1 gibberellic acid (GA3), 2.0 mg L−1 BAP, 0.5 mg L−1 adenine sulfate (AdS), and 20% ULE. Well-rooted plantlets were successfully acclimatized in the greenhouse with 70% survival rate. Results suggest that U. lactuca extract-derived silver nanoparticles could be used as biostimulants for the enhancement of somatic embryogenesis and plant regeneration rate in G. superba.

Abiotic stress conditions lead to the defects in plant growth and development and also reduction in flowering and fertility. Under prolonged stresses, imminent death of the plants has been observed. To cope with such stress conditions, plants accumulate a wide variety of organic solutes called osmolytes. Osmolytes are accumulated in bacteria, lower, and higher plants as a response primarily to abiotic stress. They encompass amino acids such as proline, tertiary sulfonium, and quaternary ammonium compounds like beatines, sugars (trehalose), and polyhydric alcohols (mannitol, sorbitol, pinitol, etc.). Osmolytes are accumulated in the cytoplasm as well as in chloroplasts in certain cases for osmotic adjustment under stress conditions. This enables the plants to absorb water and survive under stress. Out of the many phytohormones that play diverse roles during abiotic stress, abscisic acid (ABA) is an important one and perceived by plants by a core signaling module. As an integral part of signal transduction during stress conditions, ABA and other hormones regulate not only stomatal closure, but also a wide array of gene expressions including osmolyte biosynthetic pathway genes. Many signal molecules like nitric oxide, carbon monoxide, and hydrogen sulfide also play a vital role in osmolyte biosynthesis. Osmolytes appear to have multiple functions during stress such as osmotic adjustment and scavenging of reactive oxygen species (ROS). Thus, generation of ROS and osmolyte accumulation are linked together. This review summarizes the role played by ABA in signal transduction, the role of hormones to regulate osmolyte biosynthesis, and various functions carried out by them.

Na+ transporters play an important role during salt stress and development. The present study is aimed at genome-wide identification, in silico analysis of sodium-proton antiporter (NHX) and sodium-proton exchanger (NHE)-type transporters in Sorghum bicolor and their expression patterns under varied abiotic stress conditions. In Sorghum, seven NHX and nine NHE homologs were identified. Amiloride (a known inhibitor of Na+/H+ exchanger activity) binding motif was noticed in both types of the transporters. Chromosome 2 was found to be a hotspot region with five sodium transporters. Phylogenetic analysis inferred six ortholog and three paralog groups. To gain an insight into functional divergence of SbNHX/NHE transporters, real-time gene expression was performed under salt, drought, heat, and cold stresses in embryo, root, stem, and leaf tissues. Expression patterns revealed that both SbNHXs and SbNHEs are responsive either to single or multiple abiotic stresses. The predicted protein–protein interaction networks revealed that only SbNHX7 is involved in the calcineurin B-like proteins (CBL)- CBL interacting protein kinases (CIPK) pathway. The study provides insights into the functional divergence of SbNHX/NHE transporter genes with tissue specific expressions in Sorghum under different abiotic stress conditions.

Shoot-tip derived callus cultures of Sorghum bicolor were transformed by Agrobacterium tumefaciens as well as by bombardment methods with the mutated pyrroline-5-carboxylate synthetase (P5CSF129A) gene encoding the key enzyme for proline biosynthesis from glutamate. The transgenics were selfed for three generations and T4 plants were examined for 100 mM NaCl stress tolerance in pot conditions. The effect of salt stress on chlorophyll and carotenoid contents, photosynthetic rate, stomatal conductance, internal carbon dioxide concentration, transpiration rates, intrinsic transpiration and water use efficiencies, proline content, MDA levels, and antioxidant enzyme activities were evaluated in 40-day-old transgenic lines and the results were compared with untransformed control plants. The results show that chlorophyll content declines by 65% in untransformed controls compared to 30–38% loss (significant at P < 0.05) in transgenics but not carotenoid levels. Photosynthetic rate (PSII activity) was reduced in untransformed controls almost completely, while it declined by 62–88% in different transgenic lines. Salinity induced ca 100% stomatal closure in untransformed plants, while stomatal conductance was decreased only by 64–81% in transgenics after 4 days. The intercellular CO2 decreased by ca 30% in individual transgenic lines. Malondialdehyde (MDA) content was lower in transgenics compared to untransformed controls. The activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione reductase (GR; EC1.8.1.7) were quantified in leaves exposed to 100 mM NaCl stress and found higher in transgenics. The results suggest that transgenic lines were able to cope better with salt stress than untransformed controls by protecting photosynthetic and antioxidant enzyme activities.

Despite the fact that when subjected to salinity stress most plants accumulate high concentrations of sodium (Na(+)) and chloride (Cl(-)) ions in their tissues, major research has however been focused on the toxic effects of Na(+). Consequently, Cl(-) toxicity mechanisms in annual plants, particularly in inducing oxidative stress, are poorly understood. Here, the extent to which Na(+) and/or Cl(-) ions contribute in inducing oxidative stress and regulating the adaptive antioxidant defense is shown in two Indica rice genotypes differing in their salt tolerance. Equimolar (100 mM) concentrations of Na(+), Cl(-), and NaCl (EC ≈ 10 dS m(-1)) generated free-radical (O2 (•-), (•)OH) and non-radical (H2O2) forms of reactive oxygen species (ROS) and triggered cell death in leaves of 21-day-old hydroponically grown rice seedlings as evident by spectrophotometric quantifications and histochemical visualizations. The magnitude of ROS-mediated oxidative damage was higher in sensitive cultivar, whereas NaCl proved to be most toxic among the treatments. Salt treatments significantly increased activities of antioxidant enzymes and their isozymes including superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Na(+) and Cl(-) ions showed additive effects under NaCl in activating the antioxidant enzyme machinery, and responses were more pronounced in tolerant cultivar. The expression levels of SodCc2, CatA, and OsPRX1 genes were largely consistent with the activities of their corresponding enzymes. Salt treatments caused an imbalance in non-enzymatic antioxidants ascorbic acid, α-tocopherol, and polyphenols, with greater impacts under NaCl than Na(+) and Cl(-) separately. Results revealed that though Cl(-) was relatively less toxic than its counter-cation, its effects cannot be totally ignored. Both the cultivars responded in the same manner, but the tolerant cultivar maintained lower Na(+)/K(+) and ROS levels coupled with better antioxidant defense under all three salt treatments.

An optimized method was devised for asymbiotic seed germination, seedling development and field establishment of Eulophia nuda Lindl., an endangered orchid with tremendous therapeutic potentialities. Seeds of different ages were germinated on half and full strength MS (Murashige and Skoog), KC (Knudson) and BM1 (Van Waes and Debergh) media. Amongst various supplements,15 % coconut water (CW) and 500 mg/L casein hydrolysate proved beneficial for seed germination. BM1 fortified with CW (BM1 + CW) showed the highest germination (80.5 ± 2.1 %) after 60 days of inoculation, which was further improved to 91.3 ± 1.9 % upon incorporation of 1 mg/L each of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) and eventually 50.5 ± 2.1 % cultures developed into seedlings. BM1 + CW nourished with 2.5 mg/L BAP and 1.5 mg/L Kin (kinetin) proved best for multiple shoot induction from seedlings. Shoot numbers further increased with each successive transfer onto the same medium. Sixty shoots per shoot clump were achieved after four cycles of 30 days each. Microshoots were rooted (81.3 ± 2.4 %) on MS containing 2.0 mg/L indole-3-butyric acid (IBA) and 200 mg/L activated charcoal. Rooted plantlets were gradually acclimatized to greenhouse (70 % survival) and they exhibited normal morphology and growth characteristics. Flow-cytometry based DNA content analysis revealed that the ploidy levels were maintained in in-vitropropagated plants.

Growth, osmotic adjustment, antioxidant enzyme defense and principle medicinal component bacoside A was studied in in vitro raised shoots of Bacopa monnieri under different concentrations of KCl and CaCl2 (0, 50, 100, 150 or 200 mM). Significant reduction was observed in shoot number per culture; shoot length, fresh weight, dry weight and tissue water content (TWC) when shoots were exposed to increasing KCl and CaCl2 concentrations (50–200 mM) as compared to control. Minimum damage to the membrane as assessed by malondialdehyde (MDA) content was noticed in control in contrast to sharp increase in KCl and CaCl2 stressed shoots. Higher amounts of free proline, glycine betaine and total soluble sugars (TSS) accumulated in KCl and CaCl2 exposed shoots compared to the controls. Among different concentrations of KCl and CaCl2, increasing concentration of CaCl2 showed more increase in osmolyte accumulation. Na+ content decreased with increasing concentrations of KCl and CaCl2. Accumulation of K+ increased significantly in KCl (50–100 mM) stressed shoots as compared to control, while it decreased in CaCl2 treated shoots indicating that it prevents the uptake of K+ ions. Ca2+ accumulation significantly increased with increasing concentrations of CaCl2 up to 150 mM but decreased at higher concentrations. Shoots treated with KCl and CaCl2 (0–100 mM) showed higher antioxidant enzyme (SOD, CAT, APX and GPX) activities but KCl suppressed the activities at higher concentrations. Accumulation of bacoside A was enhanced with an increase in KCl and CaCl2 concentration up to 100 mM. It appears from the data that accumulation of osmolytes, and elevated activities of antioxidant enzymes play an important role in osmotic adjustment in shoot cultures of Bacopa and the two salts tested have a positive effect on bacoside accumulation.

Abutilon indicum exploited for its immense value has been propagated successfully through multiple shoot induction and somatic embryogenesis. Direct regeneration (8.20 ± 0.83 shoots) was achieved from nodal explants using 0.5 mg/l kinetin (Kn) in MS media. The basal callus from nodal explants turned embryogenic on subsequent introduction of 0.2 mg/l TDZ into the Kn-supplemented media, giving rise to somatic embryos. The embryogenic potential of calli expressed in terms of embryo-forming capacity (EFC) increased from 8.15 EFC to 20.95 EFC after plasmolysis. The phytochemical analysis (HPLC) for the presence of scopoletin and scoparone has revealed a unique accumulation pattern, with higher levels of scopoletin during the earlier stages and scoparone in the later stages of development. The embryogenic calli contained the highest amount of coumarins (99.20 ± 0.97 and 61.03 ± 0.47 μg/gFW, respectively) followed by regenerated plant (9.43 ± 0.20 and 36.36 ± 1.19 μg/gFW, respectively), obtained via somatic embryogenesis. Rapid multiplication of A. indicum equipped with two potent coumarins is important in order to meet the commercial demand for combat against dreadful diseases, thereby providing a new platform for plant-based drugs and their manufacture on a commercial scale.

Both cDNA including 5′UTR and 3′UTR and genomic clones of cinnamyl alcohol dehydrogenase (CAD) were isolated and characterized from a pulp-yielding leguminous tree Leucaena leucocephala (LlCAD1). The deduced amino acid sequence shared high identity with orthologous sequences of Acacia mangium × Acacia auriculiformis (83%), Medicago sativa (83%), Nicotiana tabaccum (83%) and Aralia cordata (81%). Full length cDNA contained 78 bases of 5′UTR and 283 bases of 3′UTR, while the genomic clone contained 5 exons and 4 introns. Western blot analysis revealed elevated expression of LlCAD1 in seedling roots and shoots compared to leaves. Sense and antisense CAD tobacco transgenics showed increased and reduced CAD activity accompanied by a change in monomeric lignin composition. Histochemical staining of lignin in down-regulated plants suggested an increase in aldehyde units and a decrease in S/G ratio. Down-regulation of CAD resulted in accumulation of syringic, ferulic, p-coumaric and sinapic acids compared to untransformed controls. These observations were validated by anatomical studies of down-regulated transgenic stems which showed thin walled, elongated phloem and xylem fibres, accompanied by a reduction in the density of vessel elements and amount of secondary xylem when compared to untransformed plants. Furthermore, Klason lignin analysis of CAD antisense transgenics showed 7–32% reduced lignin and normal phenotype as compared to untransformed plants. Such a reduction was not noticed in up-regulated transgenics. These results demonstrate a unique opportunity to explore the significant role that down-regulation of CAD gene plays in reducing lignin content thereby offering potential benefits to the pulp and paper industry.

cDNA and genomic clones of cinnamoyl CoA reductase measuring 1011 and 2992 bp were isolated from a leguminous pulpwood tree Leucaena leucocephala, named as LlCCR. The cDNA exhibited 80-85% homology both at the nucleotide and amino acid levels with other known sequences. The genomic sequence contained five exons and four introns. Sense and antisense constructs of LlCCR were introduced in tobacco plants to up and down-regulate this key enzyme of lignification. The primary transformants showed a good correlation between CCR transcript levels and its activity. Most of the CCR down-regulated lines displayed stunted growth and development, wrinkled leaves and delayed senescence. These lines accumulated unusual phenolics like ferulic and sinapic acids in cell wall. Histochemical staining suggested reduction in aldehyde units and increased syringyl over guaiacyl (S/G) ratio of lignin. Anatomical studies showed thin walled, elongated xylem fibres, collapsed vessels with drastic reduction of secondary xylem. The transmission electron microscopic studies revealed modification of ultrastructure and topochemical distribution of wall polysaccharides and lignin in the xylem fibres. CCR down-regulated lines showed increased thickness of secondary wall layers and poor lignification of S2 and S3 wall layers. The severely down-regulated line AS17 exhibited 24.7% reduction of Klason lignin with an increase of 15% holocellulose content. Contrarily, the CCR up-regulated lines exhibited robust growth, development and significant increase in lignin content. The altered lignin profiles observed in transgenic tobacco lines support a role for CCR down-regulation in improving wood properties of L. leucocephala exclusively used in the pulp and paper industry of India.

The enzyme aldoreductase which plays an important role in pathogenesis of diabetic retinopathy, neuropathy, and nephropathy was purified from bovine lens, and its inhibitory activity was studied with the synthesized flavone derivatives 1-(2-hydroxyphenyl)ethanone as the starting material. Experimental study revealed that 2-chloroflavone shows less inhibitory activity of 60–70% than other flavones used in the study. To validate experimental results computationally, docking studies of new flavone derivatives synthesized were performed with the enzyme aldose reductase, and the results indicate that 3-iodo, 4-methyl, 5-chloroflavone and 2-chloroflavone bind with higher and lesser affinities. Docking studies with site directed mutagenesis of Val47Ile, Tyr48His, Pro121Phe, Trp219Tyr, Cys298Ala, Leu300Pro, Ser302Arg, and Cys303Asp of the enzyme altered the inhibition activity of aldose reductase. The regression value (R2) of 0.81 between the docking scores of the known inhibitors and the experimental logIC50 indicates the reliability of the docking studies. Biological activity and carcinogenic properties predict that 3-iodo, 4-methyl, 5-chloroflavone is the best flavone inhibitor against aldose reductase.

A protocol for plant regeneration via somatic embryogenesis was developed in two chickpea (Cicer arietinum L.) cultivars ICCV-10 and Annigeri. Somatic embryos were induced from immature cotyledons on Murashige and Skoog’s (MS) medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), α-naphthaleneacetic acid (NAA) and picloram alone or in combination with 0.5 — 2.0 mg dm−3 N6-benzylaminopurine (BA) or kinetin (KIN). NAA was better for somatic embryo induction compared to other auxins. The well formed, cotyledonary shaped embryos germinated into plantlets with 36.6 % frequency on MS medium supplemented with 2.0 mg dm−3 BA + 0.5 mg dm−3 abscisic acid (ABA). The frequency of embryogenesis and plantlet regeneration was higher in cv. ICCV-10 as compared to cv. Annigeri. Regenerated plants were transferred to soil (40 % survival) and grown to maturity. Histological studies of explants at various developmental stages of somatic embryogenesis reveled that somatic embryos developed directly from the cotyledon cells and they were single cell origin.

Δ1-pyrroline-5-carboxylate synthetase (P5CS) is a proline biosynthetic pathway enzyme and is known for conferring enhanced salt and drought stress in transgenics carrying this gene in a variety of plant species; however, the wild-type P5CS is subjected to feedback control. Therefore, in the present study, we used a mutagenized version of this osmoregulatory gene-P5CSF129A, which is not subjected to feedback control, for producing transgenic indica rice plants of cultivar Karjat-3 via Agrobacterium tumefaciens. We have used two types of explants for this purpose, namely mature embryo-derived callus and shoot apices. Various parameters for transformation were optimized including antibiotic concentration for selection, duration of cocultivation, addition of phenolic compound, and bacterial culture density. The resultant primary transgenic plants showed more enhanced proline accumulation than their non-transformed counterparts. This proline level was particularly enhanced in the transgenic plants of next generation (T1) under 150 mM NaCl stress. The higher proline level shown by transgenic plants was associated with better biomass production and growth performance under salt stress and lower extent of lipid peroxidation, indicating that overproduction of proline may have a role in counteracting the negative effect of salt stress and higher maintenance of cellular integrity and basic physiological processes under stress.

Accumulation of proline, activities of peroxidase (POX), catalase (CAT), phenylalanine ammonia lyase (PAL) and malate dehydrogenase (MDH) were studied during different developmental stages of somatic embryos in chickpea. Callus cultures that did not form somatic embryos served as control. While increased levels of proline and POX activity were noticed in globular stages of embryos, CAT activity increased during early and late heart-shaped embryo formation indicating tissue-specific activation of these enzymes. The activity of PAL reached a peak during torpedo and cotyledonary stages of embryo development. On the other hand, MDH activity enhanced during the germination of somatic embryos inferring more requirement of energy during this stage. Electrophoretic (sodium dodecyl sulfate polyacrylamide gel electrophoresis) pattern of proteins revealed that ten bands are associated with non-embryogenic tissues, whereas 11 bands with globular, heart, torpedo and cotyledonary stages of embryo development and nine bands during the germination stage of embryos. Two extra stage-specific protein bands with molecular masses of 16 and 18 kDa appeared during globular, heart, torpedo, and cotyledonary stages. But, these bands disappeared during germination of embryos and are absent in non-embryogenic cultures. This study thus may help in the identification of proteins and the role of above enzymes during different developmental stages of somatic embryo induction and their maturation in a recalcitrant leguminous crop plant chickpea.

Caffeoyl coenzyme A O-methyltransferase (CCoAOMT) is an important enzyme that participates in lignin biosynthesis especially in the formation of cell wall ferulic esters of plants. It plays a pivotal role in the methylation of the 3-hydroxyl group of caffeoyl CoA. Two cDNA clones that code CCoAOMT were isolated earlier from subabul and in the present study; 3D models of CCoAOMT1 and CCoAOMT2 enzymes were built using the MODELLER7v7 software to find out the substrate binding sites. These two proteins differed only in two amino acids and may have little or no functional redundancy. Refined models of the proteins were obtained after energy minimization and molecular dynamics in a solvated water layer. The models were further assessed by PROCHECK, WHATCHECK, Verify_3D and ERRAT programs and the results indicated that these models are reliable for further active site and docking analysis. The refined models showed that the two proteins have 9 and 10 alpha-helices, 6 and 7 beta-sheets respectively. The models were used for docking the substrates CoA, SAM, SAH, caffeoyl CoA, feruloyl CoA, 5-hydroxy feruloyl CoA and sinapyl CoA which showed that CoA and caffeoyl CoA are binding with high affinity with the enzymes in the presence and absence of SAM. It appears therefore that caffeoyl CoA is the substrate for both the isoenzymes. The results also indicated that CoA and caffeoyl CoA are binding with higher affinity to CCoAOMT2 than CCoAOMT1. Therefore, CCoAOMT2 conformation is thought to be the active form that exists in subabul. Docking studies indicated that conserved active site residues Met58, Thr60, Val63, Glu82, Gly84, Ser90, Asp160, Asp162, Thr169, Asn191 and Arg203 in CCoAOMT1 and CCoAOMT2 enzymes create the positive charge to balance the negatively charged caffeoyl CoA and play an important role in maintaining a functional conformation and are directly involved in donor-substrate binding.

Callus cultures from salt tolerant (CSR-10) and susceptible (Swarnadhan) varieties of Oryza sativa L. were established in Murashige and Skoog's (MS) medium containing lethal concentrations (50 mM) of rubidium chloride (RbCl) as a selective agent. While 95-100% cells were viable in callus cultures grown without RbCl, viability was 75% in 50 mM RbCl selected cultures. Growth of RbCl selected calli in presence of salt was comparable to that of callus grown without it. Cells tolerant to RbCl showed more vacuoles and accumulated more K(+) in comparison with their corresponding controls. Suspension cultures were established and uptake of (86)Rb(+) was measured at 10 and 20 min intervals, which revealed a linear relationship between the absorption of K(+) and time. Callus cultures (560-day-old) tolerant to 50 mM RbCl regenerated shoots with 35-40% frequencies in both the varieties, but the same age-old callus grown in the medium devoid of RbCl did not show any organogenesis. Callus cultures that are tolerant to 50 mM RbCl when exposed to 25 mM LiCl, 50 mM NaCl, 50 mM KCl and 25 mM CsCl also exhibited cross tolerance in both the varieties. This is the first time that a callus line of rice resistant to RbCl was raised and shown to accumulate a major cation K(+ )and also an increased influx of it.

This study describes a protocol for the induction of high frequency somatic embryogenesis directly from immature inflorescence explants in three sorghum genotypes (SPV-462, SPV-839, and M35-1). The effect of various growth regulators on somatic embryogenesis was investigated. High frequency somatic embrogenesis was obtained on Murashige and Skoog (MS) medium supplemented with 2 mg l−1 2, 4-dichlorophenoxyacetic acid (2, 4-D), and addition of 0.5 mg l−1 kinetin (KN) in the medium further improved the formation of somatic embryos per explant in all genotypes. The presence of 1.5 mg l−1 6-benzylaminopurine plus 1.0 mg l−1 KN in MS medium was most efficient for maturation and germination of somatic embryos. The genotype SPV-462 performed better than SPV-839 and M35-1 in terms of induction and germination of somatic embryos. Organogenesis also occurred in callus of all genotypes at the frequency of 20–25%. Regenerated plants from somatic embryos were successfully acclimatized in soil in the greenhouse...

This study reports a protocol for plant regeneration from cultured explants of green gram [Vigna radiata (L.) Wilezek] via somatic embryogenesis. Somatic embryos were induced from nature cotyledons of var., TAP-7 and Pusa Baisaki when cultured on Murashige and Skoog (MS) medium fortified with different concentrations of 2,4-dichlorophenoxyacetic acid, α-naphthaleneacetic acid (NAA) and 2,4,5-trichlorophenoxyacetic acid singly or in combination with 2.22–8.88 μM N6-benzylaminopurine (BAP) or 2.32–9.38 μM kinetin. The type and concentration of auxin and plant genotype influenced the frequency of somatic embryogenesis. NAA was the most effective auxin for somatic embryo induction. The well-developed, cotyledonary shaped embryos of var. TAP-7 germinated into plantlets at a frequency of 56.6% on MS medium supplemented with 1.88 μM abscisic acid and 6.66 μM BAP. Regenerated plants were transferred to soil and grown to maturity with 90% survival. The protocol described here offers a good potential for genetic improvement using gene transfer techniques and the production of synthetic seeds of V. radiata.

Callus cultures of Adhatoda zeylanica Medicus were established from leaf and petiole explants. Accumulation of a bioactive pyrroloquinazoline alkaloid, vasicine, in callus cultures was detected and confirmed by thin layer chromatography, electron-ionization mass spectra, 13C NMR and high-pressure liquid chromatography analysis. The mass of vasicine obtained from leaf-derived callus cultures was found as 188 and this is comparable to that of the authentic sample. The retention time for leaf-derived extract was 10.065 and for the petiole-derived extract was 9.78 (authentic sample had 9.6 retention time) on high-performance liquid chromatography. The mass and NMR spectra were compared with the spectra obtained from the authentic sample of vasicine. Different growth regulators greatly influenced the growth of callus cultures. The accumulation of vasicine was more in leaf-derived callus grown on Murashige and Skoog (MS) medium with 2.3 μM kinetin, and 4.5 μM 2,4-dichlorophenoxyacetic acid. This is the first report on in vitro production of a pharmacologically important compound vasicine and its characterization by mass spectrometry and 13C NMR studies from callus cultures of Adhatoda zeylanica.

Enhancement of accumulation of anthraquinones in Morinda citrifolia (Noni fruit) suspension cultures was accomplished by treatment with elicitors, by ultrasonication and by controlled feeding of the carbon source in the growth medium. The elicitation was attained by additions of polyunsaturated fatty acids (linoleic acid, α-linolenic acid, arachidonic acid), methyl jasmonate, salicylate and nitric oxide (by addition of sodium nitroprusside to the medium) at different concentrations. The accumulation of anthraquinones in the elicited cultures ranged from 5 to 12 mg/g dry weight of cells, which was two to three-fold of what was attained in control cultures. Treatment by short pulses of ultrasonication enhanced the accumulation up to 2.5-fold after 16 s of sonication. A synergistic effect was achieved by simultaneously applying elicitation and controlled addition of sucrose, that increased the anthraquinone production to 16.74 mg/g of dry weight, which was more than a four-fold increase above the control cultures. The accumulation of the anthraquinones in the M. citrifolia cells was confirmed by confocal laser fluorescence microscopy. Minor fluorescence was observed from the cells in the lag phase (1-3 days), while substantially higher fluorescence was observed at late exponential and stationary phase (10-14 days). Rounder spherical cells emitted less fluorescence than elongated slender cells. The fluorescence was assumed to be a result of autofluorescent properties of the aromatic anthraquinone molecules. © 2005 Elsevier Ireland Ltd. All rights reserved.

Somatic embryogenesis was induced from suspension cultures (derived from leaf callus) of an important medicinal plant, Plumbago rosea L. While acetylsalicylic acid (ASA) alone induced embryogenesis, indole-3-acetic acid (IAA) failed to elicit a similar response. This is the first time that ASA-induced somatic embryogenesis has been reported in cultured cells. Optimal embryogenic response per culture was observed in Murashige and Skoog's medium containing a combination of ASA (8.32 μM) and IAA (5.06 μM), but 1-naphthaleneacetic acid and indole-3-butyric acid individually did not induce somatic embryogenesis. Increase in the concentration of ammonium enhanced the number of embryos formed per culture. Accumulation of plumbagin, an important naphthoquinone and a medicinal compound, was three times higher in embryogenic compared to non-embryogenic suspensions.

Cell cultures of Plumbago roseaL. (synonymous P. indica) were treated with the elicitors prepared from the fungi ( Aspergillus nigerand Rhizopus oryzae), bacteria (Bacillus subtilis and Pseudomonas aeruginosa ), yeast extract and chitosan to induce and enhance the synthesis of plumbagin. Elicitation of plumbagin production in chitosan treated cells was 6.71-fold higher compared to control cells. The treatment of cells with A. niger, R. oryzae and yeast elicitors resulted in two- to three-fold more plumbagin over control cells. Bacterial elicitors did not show much (

Callus and suspension cultures derived from leaf explants of Plumbago rosea were established and plumbagin, a naphthoquinone, was isolated from them and confirmed by 1H NMR and electron-ionization mass spectroscopy. Maximum content of plumbagin was obtained in the stationary phase of growth (4.3 mg g−1 dry cell wt). Media pH, phytohormones and carbon sources were optimized for biomass and plumbagin accumulation. Cell aggregates, measuring 500 μm in diam, produced 8.2 g dry cell wt l−1, but larger aggregates (above 500 μm) favored plumbagin accumulation with an yield of 4.5 mg g−1 dry cell wt.

Plant regeneration via somatic embryogenesis was developed in two groundnut varieties. Somatic embryogenesis was induced from immature leaflets on MS medium with different concentrations of the auxins 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthaleneacetic acid (NAA) in combination with 0.5 mg/l of the cytokinin BA. The highest frequency of somatic embryo formation occurred on MS medium fortified with 20 mg 2,4-D per l. Of the two auxins tested individually 2,4-D was more effective for induction of embryogenesis as well as production of embryos. Embryo development and maturation was achieved on MS medium supplemented with N6-benzyladenine (BA) (0.5–2.0 mg/l) and 2,4-D (0.5 mg/l). Plant conversion frequency from somatic embryos was highest in presence of 2.0 mg BA per l and 0.5 mg NAA per l. The frequency of embryogenesis and plant regeneration was higher in the VRI-2 cultivar than in the other cultivar tested. Regenerated plants were transferred to soil, grown to maturity, and produced viable seeds.

Starch, total sugars, reducing sugars and protein contents and the specific activities of hydrolytic enzymes such as amylase, Phosphorylase, soluble acid invertase, wall-bound acid invertase, sucrose synthetase, acid and alkaline phosphatases and ribonuclease were determined in root forming, shoot forming and non-organ-forming callus cultures of tobacco. Organ-forming cultures not only showed higher amounts of the above metabolites but also higher enzyme activities compared to non-organ-forming cultures. The activities of these enzymes in relation to organogenesis is discussed.

Induction of somatic embryogenesis, shoot organogenesis, and subsequent plant regeneration in niger seem to be dependent on genotype, choice of explant, and composition of media growth regulators. Two distinct regeneration protocols have been developed for somatic embryogenesis and shoot organogenesis. Somatic embryogenesis was induced from epicotyls and cotyledonary explants (9 to 35%) (but not from hypocotyls and roots) in presence of 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxypropionic acid. These embryos matured in MS medium containing Kinetin plus naphthalene acetic acid (NAA), Kinetin plus Zeatin, and Kinetin plus abscisic acid (ABA). Matured embryos could be germinated on LS and MS basal media without hormones. Non-embryogenic callus initiated on Linsmaier and Skoog’s (LS) medium from cotyledons of six different genotypes produced shoots (9 to 32%) on Murashige and Skoog’s (MS) medium fortified with 6-benzylaminopurine (BAP, 0.5 mg · liter−1), and BAP (1 mg · liter−1) plus NAA (0.1 mg · liter−1). These shoots were rooted with 100% frequency by using indole-3-acetic acid or NAA and transferred successfully to the soil.

Vigna Δ1-pyrroline-5-carboxylate synthetase (P5CS) cDNA was transferred to chickpea (Cicer arietinum L.) cultivar Annigeri via Agrobacterium tumefaciens mediated transformation. Following selection on hygromycin and regeneration, 60 hygromycin-resistant plants were recovered. Southern blot analysis of five fertile independent lines of T0 and T1 generation revealed single and multiple insertions of the transgene. RT-PCR and Western blot analysis of T0 and T1 progeny demonstrated that the P5CS gene is expressed and produced functional protein in chickpea. T1 transgenic lines accumulated higher amount of proline under 250 mM NaCl compared to untransformed controls. Higher accumulation of Na+ was noticed in the older leaves but negligible accumulation in seeds of T1 transgenic lines as compared to the controls. Chlorophyll stability and electrolyte leakage indicated that proline overproduction helps in alleviating salt stress in transgenic chickpea plants. The T1 transgenics lines were grown to maturity and set normal viable seeds under continuous salinity stress (250 mM) without any reduction in plant yield in terms of seed mass.

In the present study, 44 arsenic-resistant bacteria were isolated through serial dilutions on agar plate with concentrations ≥0.05 mM of sodium arsenite and ≥10 mM of sodium arsenate from Mandovi and Zuari--estuarine water systems. The ars genotype characterization in 36 bacterial isolates (resistant to 100 mM of sodium arsenate) revealed that only 17 isolates harboured the arsA (ATPase), B (arsenite permease) and C (arsenate reductase) genes on the plasmid DNA. The arsA, B and C genes were individually detected using PCR in 16, 9 and 13 bacterial isolates respectively. Molecular identification of the 17 isolates bearing the ars genotype was carried using 16S rDNA sequencing. A 1300 bp full length arsB gene encoding arsenite efflux pump and a 409 bp fragment of arsC gene coding for arsenate reductase were isolated from the genera Halomonas and Acinetobacter. Phylogenetic analysis of arsB and arsC genes indicated their close genetic relationship with plasmid borne ars genes of E. coli and arsenate reductase of plant origin. The putative arsenate reductase gene isolated from Acinetobacter species complemented arsenate resistance in E. coli WC3110 and JM109 validating its function. This study dealing with isolation of native arsenic-resistant bacteria and characterization of their ars genes might be useful to develop efficient arsenic detoxification strategies for arsenic contaminated aquifers.

Callus initiation from seedling explants of niger (Guizotia abyssinica Cass) cv. Ootacamund was found to be better on LS medium containing kinetin (1.4 μM) plus 2,4-dichlorophenoxyacetic acid (9 μM) than its analogues. Embryoids were induced directly from cotyledons on LS medium supplemented with 2,4,5-trichlorophenoxyacetic acid and 2,4,5-trichlorophenoxypropionic acid. When cotyledon-derived callus was subcultured onto medium with 10.7 μM naphthalene-acetic acid and 2.3 μM kinetin, embryogenesis was observed. Multiple shoots were obtained from cotyledonary explants in presence of MS medium containing 4.4 μM benzyladenine and 11.4 μM indoleacetic acid. Regenerated plants that were transferred to pots and grown to maturity were morphologically normal and fertile.

Activities of α- and β-glucosidases, α- and β-galactosidase, α-mannosidase, β-1,3-glucanase, acid and neutral invertases were detected in the cytoplasmic fraction as well as in cell walls isolated from callus cultures of cotton

In an effort to develop potent anti-inflammatory and antithrombotic drugs, a series of new 4-(2-phenyltetrahydrofuran-3-yl) benzene sulfonamide analogs were designed and docked against homology models of human cyclooxygenase-2 (COX-2), lipoxygenase and thromboxane synthase enzymes built using MODELLER 7v7 software and refined by molecular dynamics for 2 ns in a solvated layer. Validation of these homology models by procheck, verify-3D and ERRAT programs revealed that these models are highly reliable. Docking studies of 4-(2-phenyltetrahydrofuran-3-yl) benzene sulfonamide analogs designed by substituting different chemical groups on benzene rings replacing 1H pyrazole in celecoxib with five membered thiophene, furan, 1H pyrrole, 1H imidazole, thiazole and 1,3-oxazole showed that diaryl furan molecules showed good binding affinity towards mouse COX-2. Further, docking studies of diaryl furan derivatives are likely to have superior thromboxane synthase and COX-2 selectivity. Docking studies against site directed mutagenesis of Arg120Ala, Ser530Ala, Ser530Met and Tyr355Phe enzymes displayed the effect of inhibition of COX-2. Drug likeliness and activity decay for these inhibitors showed that these molecules act as best drugs at very low concentrations.

Ornithine delta-aminotransferase (OAT) is an important enzyme in proline biosynthetic pathway and is implicated in salt tolerance in higher plants. OAT transaminates ornithine to pyrroline 5-carboxylate, which is further catalyzed to proline by pyrroline 5-carboxylate reductase. The Vigna aconitifolia OAT cDNA, encoding a polypeptide of 48.1 kDa, was expressed in Escherichia coli and the enzyme was partially characterized following its purification using (NH(4))(2)SO(4) precipitation and gel filtration techniques. Optimal activity of the enzyme was observed at a temperature of 25 degrees C and pH 8.0. The enzyme appeared to be a monomer and exhibited high activity at 4mM ornithine. Proline did not show any apparent effect but isoleucine, valine and serine inhibited the activity when added into the assay mixture along with ornithine. Omission of pyridoxal 5'-phosphate from the reaction mixture reduced the activity of this enzyme by 60%. To further evaluate these biochemical observations, homology modeling of the OAT was performed based on the crystal structure of the ornithine delta-aminotransferase from humans (PDB code 1OAT) by using the software MODELLER6v2. With the aid of the molecular mechanics and dynamics methods, the final model was obtained and assessed subsequently by PROCHECK and VERIFY-3D graph. With this model, a flexible docking study with the substrate and inhibitors was performed and the results indicated that Gly106 and Lys256 in OAT are the important determinant residues in binding as they have strong hydrogen bonding contacts with the substrate and inhibitors. These observations are in conformity with the results obtained from experimental investigations.

Summary The effect of aluminium (Al) on seedlings of two rice cultivars, Pusa Basmati and Vikas was investigated after different hours of exposure to 80 μmol/L of external Al supply. With increasing time of exposure, the growing seedlings readily absorbed Al and its localization was greater in roots than shoots. Prolonged exposure to Al intensified lipid peroxidation, changed the activities of SOD and peroxidase and caused DNA damage. However, differential responses were observed between the seedlings of two rice cultivars under Al stress. A close inverse relationship existed between decreased root growth and increased Al accumulation, lipid peroxidation, SOD, peroxidase activities and DNA damage. The results demonstrate that roots are the major sites of Al localization and accumulation of Al promoted oxygen free radicals mediated peroxidation of membranes as evidenced by increased MDA levels and the activities of SOD and peroxidase. Our results for the first time showed that Al can cause DNA damage in rice.

Cell cultures of Plumbago rosea were immobilized in calcium alginate and cultured in Murashige and Skoog's basal medium containing 10 mM CaCl 2 for the production of plumbagin, an important medicinal compound. Studies were carried to find out the impact of immobilization on the increased accumulation of this secondary metabolite. Immobilization in calcium alginate enhanced the production of plumbagin by three, two and one folds compared to that of control, un-crosslinked alginate and CaCl 2 treated cells respectively. Cell loading at a level of 20% to the polymer volume (Na-alginate) was optimal and maximum plumbagin was obtained. At higher cell loading (40–50%), lower plumbagin accumulation was noticed. Addition of 200 mg l −1 chitosan as an elicitor to the immobilized cells resulted in eight and two folds higher accumulation of plumbagin over control and immobilized cells. Also, more than 70% of the plumbagin was released into the medium, which is highly desirable for easy recovery of the product. Sucrose utilization rate of the cells was higher when cells were subjected to in situ product removal using Amberlite XAD-7. This may indicate that the toxicity of plumbagin was reduced on cells when it was removed from the medium. Cells subjected to combined treatments of chitosan, immobilization and in situ extraction showed a synergistic effect and yielded 92.13 mg g −1 DCW of plumbagin which is 21, 5.7, 2.5 times higher than control, immobilized, immobilized and elicited cells respectively.

Cefotaxime ( 50 and 100 mg/1 ), a cephalosporin antibiotic and the amino acids asparagine and proline (200 mg/l) enhanced the production of embryogenic callus, increased the frequency of plant regeneration, and delayed the loss of regeneration potential in immature embryo-derived callus cultures ofSorghum bicolor (L.) Moench. Although these compounds did not promote callus induction or growth of callus, they influenced plant regeneration considerably in 10 low responding genotypes of grain and high anthocyanin containing sweet sorghums.

Nodal explants (0.5 to 0.8 cm long) isolated from 2-year old shrubs of guayule, Parthenium argentatum Gray, when cultured on MS medium supplemented with different concentrations of KN, BAP, 2,4-D, 2,4-D + BAP, NAA and NAA + BAP produced callus tissues and shoots simultaneously with varying frequencies. Shoots were regenerated with a high frequency (80-88%) from callus on MS medium containing NAA + BAP with or without glutamine. Addition of glutamine to these media improved considerably the number of shoots formed from a known amount of callus. Shoots could be regenerated from 200 day old callus cultures with a very high frequency but the organogenetic capacity declined thereafter. Increase in the concentration of sucrose (upto 4%) significantly enhanced the shoot forming ability of callus, but higher concentrations (6%) suppressed it. Rooting was induced only in dark when IAA, IBA and NAA were used, but 2,4-D could induce them both in light and dark. The system is suitable for the mass propagation of this important rubber yielding plant.