Muhammad Fayyaz Chaudhary

Expression of rol genes in transgenic soybean (Glycine max L.) leads to changes in plant phenotype, leaf morphology, and flowering time

Soybean (Glycine max L.) cultivar NARC-4 was transformed with constructs carrying rolA, rolB, or rolC genes, each under the control of the Cauliflower Mosaic Virus 70S promoter. Cotyledonary nodes of soybean seeds were infected with Agrobacterium tumefaciens strain LBA4404 carrying one of the three rol genes, along with nptII in the plasmid pLBR. The efficiency of the transformation varied slightly among the three constructs, with frequencies of 6, 7, and 5% for the rolA, rolB, and rolC genes, respectively, being observed. Southern blot analysis confirmed the integration of rol genes in the soybean genome with varying numbers of copies of the transgene. All transformed plants showed enhanced rooting, but the number of adventitious roots was higher for transformants carrying the rolB transgene. rolA and rolC transformants showed dwarf phenotypes, clustered branching, and variations in leaf morphology. Furthermore, these plants flowered within a short period of time and produced lower numbers of flowers. rolB transformants showed variations in phenotype, including dwarf to semi-dwarf and shrubby growth, abnormal stem growth, short internodes, variations in leaf morphology, and greenish to yellowish-green colored leaves. These plants also flowered early, but dwarf plants produced low numbers of flowers, while shrubby plants produced high numbers of flowers, but these were mostly infertile.

Hormonal regulation for callogenesis and organgenesis of Artemisia absinthium L

Callus cultures were induced from leaf and stem explants of Artemisia absinthium, at different auxin and cytokinin concentrations. Moderate concentrations of growth regulators either in combination or in single in MS medium produced friable, light green and non-embryogenic callus from both explants. These totipotent cells gave rise to shoots when transferred to same or different growth regulator containing medium as second subculture. Complete rooting was achieved on full and half strength basal MS medium supplemented with different auxin concentrations. Synergetic effect of plant growth regulator plays an important role in callus induction and cell differentiation.

Comparison of transgenic plant production for bacterial blight resistance in Pakistani local rice ( Oryza sativa L.) cultivars

The study was carried out to improve bacterial leaf blight resistance in three rice cultivars (Basmati - 370, DR - 82 and IR - 6) by Agrobacterium mediated transformation system. Three week-old scutellum derived calli were infected with Agrobacterium strain EHA101, containing binary vector pTCL5 which has Xa 21 gene. Different levels of acetosyringone were tested to enhance transformation efficiency. Acetosyringone at 300 iM showed 56.6% GUS expression with 100 and 200 iM acetosyringone showing 13.3 and 30.0% GUS expression, respectively. Maximum transformation efficiency was obtained using DR - 82 with calli exposed to 300 iM acetosyringone for 2 min. Direct hygromycin selection with 48 h of co-cultivation was superior to pre-selection in all three cultivars. Transient GUS expression was 51.4% while stable GUS expression in calli was 18.8%. PCR analysis confirmed the presence of the Xa 21 gene in transformed regenerated plants. Stable varietal transformation efficiency was DR - 82 > Basmati-370 > IR - 6. Resistance of transgenic plants against Xanthomonas oryzae pathovar oryzae was evaluated with various strains/isolates at the seedling stage. All PCR positive transgenic plants of DR - 82 and Basmati - 370 were resistant with lesion areas less than 5% of the inoculated leaf area. The tested transgenic plants were resistant to all the indigenous and exotic strains tested due to the broad spectrum protection provided by the Xa 21 gene.

Response of nitrogen assimilating enzymes during in vitro culture of Argyrolobium roseum

Abstract Nitrogen assimilating enzymes play curtail role during un-differentiation and re-differentiation of plant cells. To investigate role and pattern of glutamine synthetase (GS), nitrate reductase (NR) and glutamate dehydrogenase (GDH) during in vitro life cycle of Argyrolobium roseum this study was conducted. The concentrations of these enzymes were determined during seed germination; callus induction from leaf, stem and root explants; shoot regeneration from callus; root development and acclimatization stages. GS and NR enzymes showed ascending pattern during in vitro plant development from seed while GDH concentration decreased during this process. Completely reverse pattern was showed by these enzymes during callogenesis and proliferation phase. Increase in GS and NR activities was noticed in regenerated leaves and stem during shoots and roots developmental phases; and vice verse for GDH. The acclimatization stress also up lifted NR and GS activities in leaf, stem and root tissues. This study highlights the importance of nitrogen assimilating enzymes (NR, GS, and GDH) during growth and development of A. roseum in vitro culture.

Salicylic acid and ascorbic acid retrieve activity of antioxidative enzymes and structure of Caralluma tuberculata calli on PEG stress

Biochemical adaptations and morphological changes are cellular aptitude originated on biotic and abiotic stresses. Polyethylene glycol (PEG) induces drought stress in the nutrient solution. In the present investigation, Caralluma tuberculata calli is exposed to PEG and antioxidative molecules. By increasing the level of antioxidative enzymes (SOD, POD, CAT, APX, and GR), the PEG-stressed calli falls off upon exposure to non-enzymatic antioxidants (ascorbic acid and salicylic acid). Under PEG-stress, several cellular and sub-cellular changes such as alteration in plasma membrane thickness, change in nucleus shape, increase in nucleoli, deformation of thylakoid membranes, and increase in plastoglobuli are observed through electron microscopic images. From our results we conclude that application of PEG (a drought causative agent) leads to an increase in the level of antioxidative enzymes and also deformation of cellular organelles. However, application of ascorbic acid and salicylic acid eradicate drought effect induced by PEG.

Low-temperature synthesis of hierarchical structures of copper oxide and their superior biological activity

In this work, the authors report a facile low-temperature wet-chemical route to prepare morphology-tailored hierarchical structures (HS) of copper oxide. The preparation of copper oxide collides was carried out using varying concentrations of copper acetate and a reducing agent at a constant temperature of 50°C. The prepared HS of CuO were characterised by powdered X-rays diffraction that indicates phase pure having monoclinic structures. The morphology was further confirmed by field-emission scanning electron microscope. It reveals a difference in shape and size of copper oxide HS by changing the concentration of reactants. In order to evaluate the effect of H2O2 on CuO NPs, the prepared CuO are modified by treatment with H2O2. In general trend, CuOH2O2 collide showed enhanced protein kinase inhibition, antibacterial (maximum zone 16.34 mm against Staphylococcus aureus) and antifungal activities in comparison to unmodified CuO collides. These results reveal that CuO HS exhibit antimicrobial properties and can be used as a potential candidate in pharmaceutical industries.