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

Assessment of genetic diversity in China aster [Callistephus chinensis (L.) Nees

China aster [Callistephus chinensis (L.) Nees] is a flowering annual mainly cultivated for loose flower and cut flower, bedding and pot culture. To assess the genetic diversity, 42 genotypes were evaluated for fourteen quantitative traits. The genotypes were found to be highly variable for the traits such as plant height, plant spread, flower stalk length, 100 flower weight, number of flowers per plant, weight of flowers per plant and flower yield per hectare. However, low variability was recorded for vase life and shelf life. The genotypes were broadly grouped into two clusters, which were further divided into cluster 1a, 1b and cluster 2a, 2b, respectively. All the genotypes in cluster 1a were vigorous and medium flowering, whereas, genotypes in cluster 1b were tall, erect, vigorous and late flowering. The cluster 2a comprises of the genotypes with short stature, small flower and early flowering, however, cluster 2b contains only two genotypes. In principal component analysis (PCA) PC1 was highly correlated to flower yield, weight of flowers/plant, flower stalk length and plant height and PC2 was highly positively correlated to shelf life and vase life and negatively correlated to 100 flower weight. The results suggested that the existing variation in China aster genotypes could be used for the development of trait-specific novel genotypes

Evaluation of tuberose genotype IIHR 17-23SP-08 (IC0642158) for flower yield, quality and response to biotic stress

Tuberose (Agave amica, family Asparagaceae) is an important commercial flower crop valued for its spectacular fragrant flowers. An experiment was conducted to evaluate the single petalled tuberose genotypes for growth, flowering, flower yield, concrete yield and response to biotic stress for two consecutive years from 2020 to 2022. Tuberose genotype IIHR 17-23SP-08 was found to be superior with highest plant height (55.53 cm), early flowering (94.93 days), highest number of spikes/plant (8.47), longest spikes (114.61cm) and rachis (32.11cm) and maximum number of florets/spike (54.87). The matured bud weight of IIHR 17-23SP-08 was 1.29 g, which is preferable in the medium segment range with higher number of flower buds (725 buds per kg). It is a high yielder producing the highest number of spikes/m2 (76.20) and loose flower yield 18.88 t/ha/year among the genotypes evaluated. The genotype IIHR 17-23SP-08 was also found to be a good multiplier with the maximum bulb production of 8.94 bulbs per clump. It was found to be resistant to root knot nematode (Meloidogyne incognita) and tolerant to leaf burn disease (Alternaria polianthi) under field conditions. It was found suitable as loose flower for garland preparation with the shelf life of 2 days under ambient conditions and for concrete extraction with the concrete yield of 0.095%. It produces white buds (RHS colour: NNI55D, white group, Fan 4) with green tinge on the tip. Thus, the genotype IIHR 17 23SP 08 was found promising and novel among the single types with better flower and bulb yield parameters

Isolation and Partial Characterisation of a Novel Lectin from Aegle marmelos Fruit and Its Effect on Adherence and Invasion of Shigellae to HT29 Cells

Lectins are a class of ubiquitous proteins/glycoproteins that are abundantly found in nature. Lectins have unique carbohydrate binding property and hence have been exploited as drugs against various infectious diseases. We have isolated one such novel lectin from the fruit pulp of Aegle marmelos. The isolated lectin was partially characterised and its effect against Shigella dysenteriae infection was evaluated. The isolated lectin was found to be a dimeric protein with N-acetylgalactosamine, mannose and sialic acid binding specificity. The effect of Aegle marmelos fruit lectin on the adherence of Shigella dysenteriae to human colonic epithelial cells (HT29 cells) was evaluated by Enzyme Linked Immune Sorbent Assay and invasion was analysed. The protective nature of the Aegle marmelos fruit lectin was assessed by analyzing apoptosis through dual staining method. Aegle marmelos fruit lectin significantly inhibited hemagglutination activity of Shigella and its minimum inhibitory concentration is 0.625 µg/well. Further, at this concentration lectin inhibited Shigella dysenteriae adherence and invasion of HT29 cells and protects the HT29 cells from Shigella dysenteriae induced apoptosis. To conclude, isolated lectin dimeric protein with N-acetylgalactosamine, Mannose and sialic acid binding specificity and inhibits adherence and invasion of Shigellae to HT29 cells thus, protects the host

Distinct Roles for Dectin-1 and TLR4 in the Pathogenesis of Aspergillus fumigatus Keratitis

Aspergillus species are a major worldwide cause of corneal ulcers, resulting in visual impairment and blindness in immunocompetent individuals. To enhance our understanding of the pathogenesis of Aspergillus keratitis, we developed a murine model in which red fluorescent protein (RFP)-expressing A. fumigatus (Af293.1RFP) conidia are injected into the corneal stroma, and disease progression and fungal survival are tracked over time. Using Mafia mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, we demonstrated that the presence of resident corneal macrophages is essential for production of IL-1β and CXCL1/KC, and for recruitment of neutrophils and mononuclear cells into the corneal stroma. We found that β-glucan was highly expressed on germinating conidia and hyphae in the cornea stroma, and that both Dectin-1 and phospho-Syk were up-regulated in infected corneas. Additionally, we show that infected Dectin-1−/− corneas have impaired IL-1β and CXCL1/KC production, resulting in diminished cellular infiltration and fungal clearance compared with control mice, especially during infection with clinical isolates expressing high β-glucan. In contrast to Dectin 1−/− mice, cellular infiltration into infected TLR2−/−, TLR4−/−, and MD-2−/− mice corneas was unimpaired, indicating no role for these receptors in cell recruitment; however, fungal killing was significantly reduced in TLR4−/− mice, but not TLR2−/− or MD-2−/− mice. We also found that TRIF−/− and TIRAP−/− mice exhibited no fungal-killing defects, but that MyD88−/− and IL-1R1−/− mice were unable to regulate fungal growth. In conclusion, these data are consistent with a model in which β-glucan on A.fumigatus germinating conidia activates Dectin-1 on corneal macrophages to produce IL-1β, and CXCL1, which together with IL-1R1/MyD88-dependent activation, results in recruitment of neutrophils to the corneal stroma and TLR4-dependent fungal killing

Distinct Roles for Dectin-1 and TLR4 in the Pathogenesis of Aspergillus fumigatus Keratitis

Aspergillus species are a major worldwide cause of corneal ulcers, resulting in visual impairment and blindness in immunocompetent individuals. To enhance our understanding of the pathogenesis of Aspergillus keratitis, we developed a murine model in which red fluorescent protein (RFP)-expressing A. fumigatus (Af293.1RFP) conidia are injected into the corneal stroma, and disease progression and fungal survival are tracked over time. Using Mafia mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, we demonstrated that the presence of resident corneal macrophages is essential for production of IL-1β and CXCL1/KC, and for recruitment of neutrophils and mononuclear cells into the corneal stroma. We found that β-glucan was highly expressed on germinating conidia and hyphae in the cornea stroma, and that both Dectin-1 and phospho-Syk were up-regulated in infected corneas. Additionally, we show that infected Dectin-1−/− corneas have impaired IL-1β and CXCL1/KC production, resulting in diminished cellular infiltration and fungal clearance compared with control mice, especially during infection with clinical isolates expressing high β-glucan. In contrast to Dectin 1−/− mice, cellular infiltration into infected TLR2−/−, TLR4−/−, and MD-2−/− mice corneas was unimpaired, indicating no role for these receptors in cell recruitment; however, fungal killing was significantly reduced in TLR4−/− mice, but not TLR2−/− or MD-2−/− mice. We also found that TRIF−/− and TIRAP−/− mice exhibited no fungal-killing defects, but that MyD88−/− and IL-1R1−/− mice were unable to regulate fungal growth. In conclusion, these data are consistent with a model in which β-glucan on A.fumigatus germinating conidia activates Dectin-1 on corneal macrophages to produce IL-1β, and CXCL1, which together with IL-1R1/MyD88-dependent activation, results in recruitment of neutrophils to the corneal stroma and TLR4-dependent fungal killing

Post translational changes to α-synuclein control iron and dopamine trafficking : a concept for neuron vulnerability in Parkinson's disease

Parkinson's disease is a multifactorial neurodegenerative disorder, the aetiology of which remains elusive. The primary clinical feature of progressively impaired motor control is caused by a loss of midbrain substantia nigra dopamine neurons that have a high α-synuclein (α-syn) and iron content. α-Syn is a neuronal protein that is highly modified post-translationally and central to the Lewy body neuropathology of the disease. This review provides an overview of findings on the role post translational modifications to α-syn have in membrane binding and intracellular vesicle trafficking. Furthermore, we propose a concept in which acetylation and phosphorylation of α-syn modulate endocytic import of iron and vesicle transport of dopamine during normal physiology. Disregulated phosphorylation and oxidation of α-syn mediate iron and dopamine dependent oxidative stress through impaired cellular location and increase propensity for α-syn aggregation. The proposition highlights a connection between α-syn, iron and dopamine, three pathological components associated with disease progression in sporadic Parkinson's disease