Agrobacterium rhizogenes mediated genetic transformation and its applications

Agrobacterium rhizogenes mediated transformation is a powerful technique in plant biotechnology that enables the rapid and efficient production of transformed hairy roots. This process is particularly advantageous for various plant species, spanning angiosperms (both dicotyledonous and monocotyledonous plants), gymnosperms, and even moss. The key element in this transformation is the root-inducing (Ri) plasmid carried by A. rhizogenes. The process begins with the introduction of A. rhizogenes to wounded plant tissues. The bacterium, being Gram-negative, harbors the Ri plasmid, which contains the transfer-DNA (T-DNA) fragment. This T-DNA integrates into the host plant genome, triggering the formation of hairy roots. The Ri T-DNA can also transmit through meiosis, ensuring that the genetic modifications are heritable. The A. rhizogenes-mediated transformation system is particularly valuable for species that are challenging to transform using Agrobacterium tumefaciens. It offers several advantages over A. tumefaciens-mediated transformation, including a faster process and a higher transformation frequency

Crucial stages and process for successful banana micropropagation through plant tissue cultutre techniques

Banana is a vegetatively propagated plant in which tissue culture is employed vastly. The apical shoot tip culture technique is capable to mass produce disease-free planting material for commercial propagation of banana seedlings. Healthy planting material serves as a major input for successful farming of year round crop. The success of tissue culture depends largely on the selection of mother suckers, in vitro culture and rooting and hardening of plants. The crucial stages for successful micropropagation are discussed in detail

Successful intracytoplasmic sperm injection with testicular spermatozoa using pentoxifylline and HOS from a male with necrozoospermia: a case report

The study was done to compare fertilization, cleavage, and pregnancy outcome of a man affected with necro zoospermia  using pentoxifylline and a hypoosmotic swelling (HOS) test to select viable spermatozoa from testicular biopsy specimens. A patient was diagnosed with necrozoospermia by semen analysis, and testicular spermatozoa were injected intracytoplasmically, using pentoxifylline and HOS (Hypo osmotic swelling test) and the following ICSI results were observed. Significantly higher fertilization rates (pentoxifylline 100% vs HOS 80%) were observed. There was no significant difference observed in cleavage rates among both groups. Finally, a healthy female infant with birth weight 3 kg was delivered at the second frozen embryo transfer cycle.it was found that selecting viable spermatozoa using pentoxifylline was more effective in fertilization and pregnancies than obtaining it through a HOS test. ICSI is effective for necrozoospermic man

Standardization of sterilization protocol for explants and its suitability for direct organogenesis in tuberose cv. Arka Vaibhav

A study was carried out to standardize the sterilization protocol for different explants (terminal stem scale,immature flower bud and tepal segment) and to select the suitable explant for the direct organogenesis of tuberose cv. Arka Vaibhav. The highest survival per cent (100) and uncontaminated cultures (0.00) of terminal stem scale explant was observed in pre-treatment with overnight soaking of terminal stem scale in the solution comprising carbendazim (0.1%), chlorothalonil (0.05%) and myristyl trimethyl ammonium bromide (cetrimide) (0.05%) and subsequently surface sterilization with 70% ethanol (1 min), 4% sodium hypochlorite (10 min) followed by 0.1% HgCl2 (15 min). The explant immature flower bud recorded the highest survival per cent (100) and maximum aseptic cultures in the treatment T1 comprised of 1.0 drop Tween-20 + 70% ethanol (30 sec) and 1% sodium hypochlorite (3 min). Pre-treatment of tepal segment explant in 0.1% carbendazim (30 min) solution followed by surface sterilization with combination of 1.0 drop Tween-20 + 70% ethanol (30 sec) followed by 1% sodium hypochlorite (3 min) registered 91.66% of survival with the minimum contamination (10%) in the treatment. Among the three explants used, the terminal stem scale was found suitable for direct organogenesis with early greenness (5.72 days) and highly responsive to shoot induction (100%) in MS medium supplemented with 4 mg/L BAP + 0.1mg/L IAA. Other two explants viz., immature flower bud and tepal segment failed to respond for direct organogenesis by shoot induction instead produced profuse callus

Over expression of anti-apoptotic gene in banana cv Rasthali enhances resistance against Fusarium oxysporum f. sp. cubense Race 1

The most popular banana cv Rasthali was transformed with anti-apoptotic gene, AtBAG4 regulated with two different promoters viz., ZmBgl and ubiquitin to enhance the tolerance levels to Fusarium oxysporum f. sp. cubense Race 1 (FOC1). The differences in gene expression driven by two promoters revealed that stronger expression of AtBAG4 gene under the ubiquitin promoter suppressed the infection and spreading processes of FOC1 in transgenic banana under standard bioassay systems. Analysis using the real time PCR showed the varying levels of AtBAG4 gene expression under two promoters. It was evident that ZmBgl driven AtBAG4 lead to lower gene expression in leaves which correlated with lesser levels of resistance to FOC1. Constitutive expression of AtBAG4 under the control of ubiquitin promoter showed increased transgene transcripts which directly correlated with the enhanced tolerance against FOC1 from seedlings stage to active vegetative phases. This study reveals the importance of constitutive expression of anti-apoptotic gene showing enhanced tolerance against the most dreaded FOC1 in highly susceptible variety Rasthali

Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins

As a result of the adaptation of life to an aerobic environment, nature has evolved a panoply of metalloproteins for oxidative metabolism and protection against reactive oxygen species. Despite the diverse structures and functions of these proteins, they share common mechanistic grounds. An open-shell transition metal like iron or copper is employed to interact with O_2 and its derived intermediates such as hydrogen peroxide to afford a variety of metal–oxygen intermediates. These reactive intermediates, including metal-superoxo, -(hydro)peroxo, and high-valent metal–oxo species, are the basis for the various biological functions of O_2-utilizing metalloproteins. Collectively, these processes are called oxygen activation. Much of our understanding of the reactivity of these reactive intermediates has come from the study of heme-containing proteins and related metalloporphyrin compounds. These studies not only have deepened our understanding of various functions of heme proteins, such as O2 storage and transport, degradation of reactive oxygen species, redox signaling, and biological oxygenation, etc., but also have driven the development of bioinorganic chemistry and biomimetic catalysis. In this review, we survey the range of O_2 activation processes mediated by heme proteins and model compounds with a focus on recent progress in the characterization and reactivity of important iron–oxygen intermediates. Representative reactions initiated by these reactive intermediates as well as some context from prior decades will also be presented. We will discuss the fundamental mechanistic features of these transformations and delineate the underlying structural and electronic factors that contribute to the spectrum of reactivities that has been observed in nature as well as those that have been invented using these paradigms. Given the recent developments in biocatalysis for non-natural chemistries and the renaissance of radical chemistry in organic synthesis, we envision that new enzymatic and synthetic transformations will emerge based on the radical processes mediated by metalloproteins and their synthetic analogs

Cloning of chitinase gene from <i style="">Bacillus thuringiensis</i>

264-269In the present investigation, 34 Bacillus thuringiensis (Bt) isolates of different agroclimatic condition were studied for fungitoxic characters and the principle involved for fungitoxicity was identified in most of the cases as exochitinases. The different Bt strains were screened for fungitoxicity and chitin degrading activity employing 4 fungal pathogens. Biochemical assay of the chitinase using glycol chitin as the substrate helped to identify the enzyme as an exochitinase. The antifungal chitinase activity on phyto-pathogenic Fusarium oxysporum f. sp. cubense was investigated in vitro by fluorescent microscopic observation. PCR was employed using chitinase gene specific primers to obtain the corresponding gene from Bt isolates. The corresponding gene was cloned and sequenced for one of the isolates and it was determined to be around 1129 bp, encoding a polypeptide of 360 amino acids. This gene was found to be highly homologous to that of chitinase of B. cereus strain 28-9

Mechanical and Microstructure Characterization of Coconut Spathe Fibers and Kenaf Bast Fibers Reinforced Epoxy Polymer Matrix Composites

AbstractIn this present study, the natural fibers such as kenaf and coconut spathe are reinforced in polymer matrix by hand layup process. Alkali treated coconut spathe and kenaf bast fibers are uniformly dispersed with epoxy resin and cured using tri-ethylene tetra amine (TETA) at 250C. The weight proportion of the polymer matrix is maintained constantly 10% whereas the proportions of the fibers are altered within the composites. The mechanical properties like tensile, flexural, impact strengths are analyzed. Fracture analysis of fiber reinforced composites and the effect of alkali treatment on fibers are also observed using scanning electron microscope (SEM)

Duplex PCR to detect both Papaya ring spot virus and Papaya leaf curl virus simultaneously from naturally infected papaya (<i style="mso-bidi-font-style:normal">Carica papaya</i> L.)

269-272Papaya, a major fruit crop in India and worldwide, is affected by many fungal and viral diseases. A mixed infection of Papaya ring spot virus (PRSV), a linear single-stranded (+) RNA genome of approx 10 kb size, and Papaya leaf curl virus (PaLCV), a bipartite Gemini virus (component A &amp; B) having circular single-stranded DNA (+) genome of about 5.2 kb, has hampered the production and productivity of papaya in many parts of world. Rapid detection techniques are important in prevention of spread of the disease in field conditions. In the present study, <span style="mso-ansi-language: EN-IN;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold">a rapid and reliable PCR based detection protocol has been standardized. Sets of primers were designed, based on the respective virus isolate sequence data available in GenBank, to obtain anticipated products of calculated size. </span