Micropropagtion of Terminalia bellerica from nodal explants of mature tree and assessment of genetic fidelity using ISSR and RAPD markers

The present study reports an efficient in vitro micropropagation protocol for a medicinally important tree, Terminalia bellerica Roxb. from nodal segments of a 30 years old tree. Nodal segments taken from the mature tree in March-April and cultured on half strength MS medium gave the best shoot bud proliferation response. Combinations of serial transfer technique (ST) and incorporation of antioxidants (AO) [polyvinylpyrrolidone, PVP (50 mg l⁻¹) + ascorbic acid (100 mg l⁻¹) + citric acid (10 mg l⁻¹)] in the culture medium aided to minimize browning and improve explant survival during shoot bud induction. Highest multiplication of shoots was achieved on medium supplemented with 6-benzyladenine (BA, 8.8 μM) and α-naphthalene acetic acid (NAA, 2.6 μM) in addition to antioxidants. Shoot elongation was obtained on MS medium containing BA (4.4 μM) + phloroglucinol (PG, 3.9 μM). Elongated shoots were transferred to half strength MS medium containing indole-3-butyric acid (IBA, 2.5 μM) for root development. The acclimatization of plantlets was carried out under greenhouse conditions. The genetic fidelity of the regenerated plants was checked using inter simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD) analysis. Comparison of the bands among the regenerants and mother plant confirmed true-to-type clonal plants.     

Regeneration and Agrobacterium-mediated genetic transformation of Terminalia bellerica Roxb.: a multipurpose tree species

An efficient in vitro transformation and plant regeneration protocol was developed for Terminalia bellerica using cotyledonary node cultures. High-frequency shoot bud proliferation was obtained on medium with 6-benzyladenine. Significant improvements in plant regeneration occurred using elevated levels of CuSO₄ and CoCl₂. Rooting occurred on a half-strength Murashige and Skoog medium containing indole-3-butyric acid. The rooted plants were acclimatized and transferred to field conditions. The genetic fidelity of the regenerated plants was confirmed using randomly amplified polymorphic DNA analysis. An Agrobacterium-mediated genetic transformation protocol was developed for Terminalia by varying several factors which influence T-DNA delivery. Southern blot analysis of regenerated plants confirmed selectable marker gene integration in transgenic plants. This transformation protocol can be utilized for further genetic manipulation of T. bellerica.     

Optimization of Ionic and Chelated Iron and Its Interaction with Disodium Ethylenediaminetetraacetic Acid for Enhancement of Plant Regeneration in Rice (Oryza sativa L)

Interactive effects of Fe₂(SO₄)3 and Na₂EDTA on callus induction and plant regeneration in indica rice (Oryza sativa cv Pusa Basmati-1) was investigated. Callus induction and subsequent plant regeneration from seed was obtained on MS medium supplemented with 11.31 µM 2,4-D and 2.68 µM NAA + 8.87 µM BAP respectively. Both the callus induction and the plant regeneration media were supplemented with different levels of Fe₂(SO₄)₃, Na₂EDTA and their combinations. Callus induction, its morphogenic potential, average number of regenerated plants as well as the appearance of the regenerants was influenced by the levels of Fe₂(SO₄)₃ and Na₂EDTA. Embryogenic callus could be induced in the presence of Fe₂(SO₄)₃ / Na₂EDTA. Iron was essential for plant regeneration. Non-chelated iron could induce callus formation as well as plant regeneration, yet the chelated form was more suitable. A higher level of Na₂EDTA in the regeneration medium was detrimental. Differential requirement of Fe₂(SO₄)₃ at induction and regeneration level was observed. Method of medium preparation affected the regeneration response. Nearly three fold increase in the number of regenerated plants was achieved with 0.05 mM Fe₂(SO₄)₃ + 0.1 mM Na₂EDTA at callus induction and 0.1 mM Fe₂(SO₄)₃+ 0.1 mM Na₂EDTA at plant regeneration and standard method of autoclaving.     

Comparative evaluation of <Emphasis Type="Italic">Populus</Emphasis> variants total sugar release and structural features following pretreatment and digestion by two distinct biological systems

Background

Populus natural variants have been shown to realize a broad range of sugar yields during saccharification, however, the structural features responsible for higher sugar release from natural variants are not clear. In addition, the sugar release patterns resulting from digestion with two distinct biological systems, fungal enzymes and Clostridium thermocellum, have yet to be evaluated and compared. This study evaluates the effect of structural features of three natural variant Populus lines, which includes the line BESC standard, with respect to the overall process of sugar release for two different biological systems.

Results

Populus natural variants, SKWE 24-2 and BESC 876, showed higher sugar release from hydrothermal pretreatment combined with either enzymatic hydrolysis or Clostridium thermocellum fermentation compared to the Populus natural variant, BESC standard. However, C. thermocellum outperformed the fungal cellulases yielding 96.0, 95.5, and 85.9% glucan plus xylan release from SKWE 24-2, BESC 876, and BESC standard, respectively. Among the feedstock properties evaluated, cellulose accessibility and glycome profiling provided insights into factors that govern differences in sugar release between the low recalcitrant lines and the BESC standard line. However, because this distinction was more apparent in the solids after pretreatment than in the untreated biomass, pretreatment was necessary to differentiate recalcitrance among Populus lines. Glycome profiling analysis showed that SKWE 24-2 contained the most loosely bound cell wall glycans, followed by BESC 876, and BESC standard. Additionally, lower molecular weight lignin may be favorable for effective hydrolysis, since C. thermocellum reduced lignin molecular weight more than fungal enzymes across all Populus lines.

Conclusions

Low recalcitrant Populus natural variants, SKWE 24-2 and BESC 876, showed higher sugar yields than BESC standard when hydrothermal pretreatment was combined with biological digestion. However, C. thermocellum was determined to be a more robust and effective biological catalyst than a commercial fungal cellulase cocktail. As anticipated, recalcitrance was not readily predicted through analytical methods that determined structural properties alone. However, combining structural analysis with pretreatment enabled the identification of attributes that govern recalcitrance, namely cellulose accessibility, xylan content in the pretreated solids, and non-cellulosic glycan extractability.

     

Phenylacetic acid improves bud elongation and in vitro plant regeneration efficiency in Helianthus annuus L.

We have developed a highly efficient three-stage protocol for plant regeneration in sunflower (Helianthus annuus L.) from embryonal cotyledons. This protocol uses phenylacetic acid (PAA) for both shoot-bud induction and the elongation of smaller buds. The medium used for inducing bud formation from the cotyledons was modified MS medium supplemented with 3 mg/l 6-benzylaminopurine (BAP) and 0.5 mg/l PAA. Buds were elongated on MS medium supplemented either with only 0.2 mg/l gibberellic acid (GA₃) or with 0.2 mg/l GA₃ + 0.1 mg/l PAA + 0.3 mg/l BAP. The elongated shoots were then transferred onto rooting medium containing 1 mg/l PAA. The complete plantlets with well-developed roots were transferred to field conditions where they survived and set normal seeds. The induction of shoot buds from embryonal cotyledons was also observed on modified MS medium supplemented with 0.5-5 mg/l BAP in combination with 0.5-5 mg/l !-naphthaleneacetic acid (NAA). In this case, the formation of callus took place along with shoot-bud formation, which hindered further development of the latter. The presence of PAA with BAP in the primary bud induction medium promoted normal development and elongation of shoot buds.     

In Vitro Culture of Kodo Millet: Influence of 2,4-D and Picloram in Combination with Kinetin on Callus Initiation and Regeneration

Immature inflorescences of kodo millet (Paspalum scrobiculatum L. cv. GPUK-3) were cultured on MS medium. Induction of embryogenic callus and subsequent somatic embryogenesis was possible on both 2,4-D and Picloram alone or with kinetin from spikelets as well as rachis. Immature inflorescence cultured on medium supplemented with lower levels of Picloram in combination with kinetin developed organogenic callus with shoot buds. Direct somatic embryo formation on rachis was observed at higher levels of Picloram in combination with kinetin. Plant regeneration was observed when calluses were transferred to α-napthaleneacetic acid (NAA) plus 6-benzylaminopurine (BA) supplemented MS medium. Histological observations provided a clear evidence for both somatic embryogenesis and shoot organogenesis. Profuse rooting was induced on phenylacetic acid (PAA) supplemented medium. Regenerated plants were successfully transferred to pots under field conditions where most of the plants survived and set normal seeds.     

Role of Tissue Factor in Mycobacterium tuberculosis-Induced Inflammation and Disease Pathogenesis

Tuberculosis (TB) is a chronic lung infectious disease characterized by severe inflammation and lung granulomatous lesion formation. Clinical manifestations of TB include hypercoagulable states and thrombotic complications. We previously showed that Mycobacterium tuberculosis (M.tb) infection induces tissue factor (TF) expression in macrophages in vitro. TF plays a key role in coagulation and inflammation. In the present study, we investigated the role of TF in M.tb-induced inflammatory responses, mycobacterial growth in the lung and dissemination to other organs. Wild-type C57BL/6 and transgenic mice expressing human TF, either very low levels (low TF) or near to the level of wild-type (HTF), in place of murine TF were infected with M.tb via aerosol exposure. Levels of TF expression, proinflammatory cytokines and thrombin-antithrombin complexes were measured post M.tb infection and mycobacterial burden in the tissue homogenates were evaluated. Our results showed that M.tb infection did not increase the overall TF expression in lungs. However, macrophages in the granulomatous lung lesions in all M.tb-infected mice, including low TF mice, showed increased levels of TF expression. Conspicuous fibrin deposition in the granuloma was detected in wild-type and HTF mice but not in low TF mice. M.tb infection significantly increased expression levels of cytokines IFN-γ, TNF-α, IL-6 and IL-1ß in lung tissues. However, no significant differences were found in proinflammatory cytokines among the three experimental groups. Mycobacterial burden in lungs and dissemination into spleen and liver were essentially similar in all three genotypes. Our data indicate, in contrast to that observed in acute bacterial infections, that TF-mediated coagulation and/or signaling does not appear to contribute to the host-defense in experimental tuberculosis.     

Baggasse Preservation: A Need for a Biotechnological Approach

ABSTRACT

Microarrays with biomolecules (e.g., DNA and proteins), cells, and tissues immobilized on solid substrates are important tools for biological research, including genomics, proteomics, and cell analysis. In this paper, the current state of microarray fabrication is reviewed. According to spot formation techniques, methods are categorized as “contact printing” and “non-contact printing.” Contact printing is a widely used technology, comprising methods such as contact pin printing and microstamping. These methods have many advantages, including reproducibility of printed spots and facile maintenance, as well as drawbacks, including low-throughput fabrication of arrays. Non-contact printing techniques are newer and more varied, comprising photochemistry-based methods, laser writing, electrospray deposition, and inkjet technologies. These technologies emerged from other applications and have the potential to increase microarray fabrication throughput; however, there are several challenges in applying them to microarray fabrication, including interference from satellite drops and biomolecule denaturization.