Selection of optimal stage for protocorm-like bodies and production of artificial seeds for direct regeneration on different media and short term storage of Dendrobium Shavin White

Micropropagation is currently the most popular method for orchid propagation through the production of protocorm-like bodies (PLBs). It is suggested that converting the PLBs into artificial seeds by encapsulation with sodium alginate can be useful for short-term preservation and distribution to the laboratories and commercial nurseries. Prior to the production of artificial seeds, the best developmental stage of PLBs based on sizes for increased conversion to plantlet was determined. PLBs were categorized based on size and presence of shoot namely ≤2 mm (S1), >2–4 mm (S2), >4–6 mm (S3), >2–4 mm with shoot (S4) and >4–6 mm with shoot (S5). S4 and S5 gave significantly higher conversion percentage (85 and 90 %, respectively) as compared to the PLBs without shoot (S1, S2 and S3). Thus, for uniformity PLBs of 3–5 mm with shoot were used for encapsulation with sodium alginate to form artificial seeds. The feasibility of germinating artificial seeds of Dendrobium Shavin White in different substrates namely; M1 (semi-solid ½ Murashige and Skoog (1962) basal medium), M2 (cotton irrigated with sterilized liquid ½ MS basal medium), M3 (cotton irrigated with sterilized distilled water) and M4 (cotton irrigated with non-sterilized distilled water) was tested. The encapsulated PLBs regenerated well in M1 where 96 % of encapsulated PLBs germinated after 12 days of inoculation and 76 % of them converted into plantlet after 37 days of inoculation while PLBs subjected to sterile distilled water gave 56 % germination and 44 % conversion after 42 and 167 days of inoculation respectively. The ability to store encapsulated PLBs would be advantageous for transport of planting materials. Encapsulated PLBs survived longer when stored at 25 ± 2 °C compared to 4 °C, 10 °C and 30 ± 2 °C whereby storage up to 75 days retained 80–92 % survival. Further storage up to 135 days retained 52 % survival. All plantlets survived after acclimatization when transferred to charcoal media under shade.     

Influence of gibberellin A<Subscript>3</Subscript> application,pH of the medium,photoperiod and temperature on the enhancement of in vitro flowering in <Emphasis Type="Italic">Vitex negundo</Emphasis> L.

Vitex negundo L. is an economically important small medicinal tree and an essential oil is extracted from its flowers. In nature, flowering is season specific and irregular, appearing only after a long vegetative phase. A very much improved protocol has been developed for the enhancement of flowering in vitro, one which increases both the number of flowers and the percentage (98.6%) of micro-plants flowering. The inclusion of gibberellin A₃ (GA₃) in the culture medium played the key role in controlling the in vitro flowering in V. negundo. The promotive effect of GA₃ was further improved by optimising pH, photoperiod and temperature. Our in vitro flower induction procedures provide an extremely effective method for further research on flowering regulation mechanisms in this important medicinal tree.     

Structure of a novel phosphotyrosine-binding domain in Hakai that targets E-cadherin

Phosphotyrosine-binding domains, typified by the SH2 (Src homology 2) and PTB domains, are critical upstream components of signal transduction pathways. The E3 ubiquitin ligase Hakai targets tyrosine-phosphorylated E-cadherin via an uncharacterized domain. In this study, the crystal structure of Hakai (amino acids 106-206) revealed that it forms an atypical, zinc-coordinated homodimer by utilizing residues from the phosphotyrosine-binding domain of two Hakai monomers. Hakai dimerization allows the formation of a phosphotyrosine-binding pocket that recognizes specific phosphorylated tyrosines and flanking acidic amino acids of Src substrates, such as E-cadherin, cortactin and DOK1. NMR and mutational analysis identified the Hakai residues required for target binding within the binding pocket, now named the HYB domain. ZNF645 also possesses a HYB domain but demonstrates different target specificities. The HYB domain is structurally different from other phosphotyrosine-binding domains and is a potential drug target due to its novel structural features.     

Inherited Interleukin-12 Deficiency: IL12B Genotype and Clinical Phenotype of 13 Patients from Six Kindreds

Interleukin-12 (IL12) is a cytokine that is secreted by activated phagocytes and dendritic cells and that induces interferon-gamma production by natural-killer and T lymphocytes. It consists of two subunits, p35 and p40, which are encoded by IL12A and IL12B, respectively. The first reported patient with a genetic cytokine disorder was a Pakistani child, who was homozygous for a large loss-of-function deletion (g.482+82_856-854del) in IL12B. This IL12-deficient child suffered from infections caused by bacille Calmette-Guérin (BCG) and Salmonella enteritidis. We herein report 12 additional patients from five other kindreds. In one kindred from India, the same large deletion that was described elsewhere (g.482+82_856-854del) was identified. In four kindreds from Saudi Arabia, a recessive loss-of-function frameshift insertion (g.315_316insA) was found. A conserved haplotype encompassing the IL12B gene suggested that a founder effect accounted for the recurrence of each mutation. The two founder mutational events-g.482+82_856-854del and g.315_316insA-were estimated to have occurred approximately 700 and approximately 1,100 years ago, respectively. Among a total of 13 patients with IL12 deficiency, 1 child had salmonellosis only and 12 suffered from clinical disease due to BCG or environmental nontuberculous mycobacteria. One patient also had clinical disease caused by virulent Mycobacterium tuberculosis, five patients had clinical disease caused by Salmonella serotypes, and one patient had clinical disease caused by Nocardia asteroides. The clinical outcome varies from case to case, since five patients (aged 2-11 years) died of overwhelming infection, whereas eight patients (aged 3-12 years) are still in good health and are not currently taking antibiotics. In conclusion, IL12 deficiency is not limited to a single kindred, shows significant variability of outcome, and should be considered in the genetic diagnosis of patients with mycobacteriosis and/or salmonellosis. To date, two founder IL12B mutations have been identified, accounting for the recurrence of a large deletion and a small insertion within populations from the Indian subcontinent and from the Arabian Peninsula, respectively.     

Alginate-encapsulation, short-term storage and plant regeneration from protocorm-like bodies of Aranda Wan Chark Kuan ‘Blue’?×?Vanda coerulea Grifft. ex. Lindl. (Orchidaceae)

This article demonstrates the single bead alginate-encapsulation and conversion (complete plantlet regeneration) from protocorm-like bodies (PLBs) of Aranda Wan Chark Kuan ??Blue???×?Vanda coerulea Grifft. ex. Lindl. (AV) (a monopodial orchid hybrid) for the first time. PLBs, induced from leaf segments of AV were isolated from in vitro proliferating PLB clusters. Individual PLBs (4?±?1?mm diameter) were encapsulated in calcium alginate beads to manage mass propagation, short-term storage and germplasm sharing. The superior gel matrix for encapsulation was obtained using 3?% sodium alginate and 75?mM calcium chloride (CaCl₂·2H₂O). Highest percentage of germination (98.1?%) and conversion (96.2?%) of encapsulated PLBs (capsules) was obtained on plant growth regulator-free half-strength MS (Murashige and Skoog, Physiol Plant 15:473?C497, 1962) medium. Successful storage of capsules, until 180?days, was achieved at 25?°C under zero-irradiance with germination and conversion frequency of 76.9 and 70.2?%, respectively. Plantlets regenerated from capsules were acclimatized successfully with 92?% survival rate.     

Effects of angiotensin II on regional afferent and efferent arteriole dimensions and the glomerular pole

The diversity of renal arteriole diameters in different cortical regions has important consequences for control of glomerular capillary pressure. We examined whether intrarenal angiotensin II (ANG II; 0.1, 1, or 5 ng. kg(-1). min(-1)) in anesthetized rabbits acts preferentially on pre- or postglomerular vessels using vascular casting. ANG II produced dose-related reductions in afferent and efferent diameters in the outer, mid, and inner cortex, without effecting arterial pressure. Afferent diameter decreased more than efferent in the outer and mid cortex (P < 0.05) but by a similar extent in juxtamedullary nephrons (P = 0.58). Calculated efferent resistance increased more than afferent, especially in the outer cortex (127 vs. 24 units; 5 ng. kg(-1). min(-1) ANG II). ANG II produced significant dose-related increases in the distance between the arterioles at the entrance to the glomerular pole in all regions. Thus afferent diameter decreased more in response to ANG II, but efferent resistance rose more due to smaller resting luminal dimensions. The results also indicate that glomerular pole dimensions change in response to ANG II.     

Cryopreservation of immature Parkia speciosa Hassk. zygotic embryonic axes following desiccation or exposure to vitrification solution

This work reports on the cryopreservation of immature zygotic embryonic axes (EA) of petai (Parkia speciosa Hassk.) for the first time. Two cryopreservation protocols, namely desiccation and vitrification method were tested individually using excised EA. Desiccation of EA to lower moisture content (MC) reduced the survival percentage but a drastic decline in survival percentage (~20 %) was recorded at 16 % MC prior to exposure to LN, rendering the EA to be sensitive to desiccation. Cryopreservation of EA after desiccation, irrespective of the MC, did not result in any survival. On the other hand, post-cryopreservation survival was obtained when the EA were exposed to plant vitrification solution-2 (PVS2) for 75–105 min. The best results were obtained when the EA were exposed to PVS2 for 90 min with an average recovery of 55.5 %. EA recovery into whole plantlets was obtained when the EA were cultured on MS medium supplemented with 2 gl^?1 activated charcoal and 0.1 mgl^?1 of the plant growth regulators α-naphthalene acetic acid, 6-benzylaminopurine and gibberellin A₃, each. EA, exposed for less than 75 min and more than 105 min to PVS2, did not show any survival after cryopreservation. The optimization of exposure time is necessary to increase survival. This study has shown that the employment of suitable method is important for conservation using cryopreservation.     

Storability, post-storage conversion and genetic stability assessment of alginate-encapsulated shoot tips of monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl.

An efficient short-term storage system of synthetic seeds, produced using in vitro shoot tips of the monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl. (AV), was developed. In vitro shoot tips (3–4 mm) were successfully encapsulated, resulting in uniform spherical beads (capsules), using 3 % sodium alginate with 75 mM CaCl₂·2H₂O. Maximum (~100 %) conversion (into plantlets with shoot and root) of capsules (or synthetic seeds) was achieved on quarter-strength Murashige and Skoog regrowth medium, while full-strength MS medium was required for effective conversion of non-encapsulated shoot tips. The capsules showed distinct difference in their response to temperature during storage. The conversion efficiency declined upon storage duration at both 4 and 25 °C, with those stored at 25 °C being more tolerant to storage. Capsules stored at 4 °C had rapid deterioration and faced complete death within 160 days while those stored for 200 days at 25 °C showed relatively high conversion (71.6 %). An inter-simple sequence repeats fingerprinting approach, employed on indiscriminately chosen plantlets from converted capsules (following 4 and 25 °C of storage), ensured the post-storage genetic stability.     

Dengue haemorrhagic fever and dengue shock syndrome: are they tumour necrosis factor-mediated disorders?

A consecutive series of 24 patients with clinical features of primary dengue infection and 22 controls (14 patients with viral fever of unknown origin and 8 healthy subjects) were assayed for serum levels of tumour necrosis factor (TNF). The acute sera of the 24 patients with clinical dengue infection were positive for dengue virus-specific IgM antibody. Clinically, 8 had dengue fever (DF), 14 dengue haemorrhagic fever (DHF) and 2 dengue shock syndrome (DSS). All 16 patients with DHF/DSS had significantly elevated serum TNF levels but the 8 DF patients had TNF levels equivalent to that in the 22 controls. A case is made for augmented TNF production having a role for the pathophysiological changes observed in DHF/DSS and mediator modulation as a possible therapeutic approach to treatment.     

Optimal hydration status for cryopreservation of intermediate oily seeds: Citrus as a case study

BACKGROUND AND AIMS: The purpose of this study was to investigate the basis of the optimal hydration status for cryopreservation of intermediate oily seeds using Citrus as a model. METHODS: The relationships between equilibrium relative humidity (RH), seed water content, presence of freezable water as determined by DSC analysis, and germination percentage after immersion in liquid nitrogen (LN) were investigated in Citrus aurantifolia, C. grandis, C. madurensis and C. reticulata. The relationship between the lipid content of seeds and their unfrozen water content was also investigated. KEY RESULTS: Independent of their level of seed desiccation tolerance, the optimal desiccation RH for seed tolerance to LN exposure was 75-80 % in the four species studied. This optimal hydration status always coincided with that at which presence of frozen water could not be detected in seed tissues during the cooling/thawing process. The unfrozen water content of seeds was variable between species and negatively correlated to seed lipid content. Using the present data, those obtained previously in seven coffee species and those reported by other authors for five other species, a significant linear relationship was found between the lipid content and the unfrozen water content of seeds. CONCLUSIONS: This study provides additional evidence that intermediate oily seeds do not withstand the presence of freezable water in their tissues during the cooling/warming process. Moreover, it offers two important applied perspectives: (1) independent of their level of desiccation tolerance, testing germination of seeds of a given oily seed species after equilibration in 75-80 % RH at 25 degrees C and LN exposure, gives a rapid and reliable evaluation of the possibility of cryopreserving whole seeds of this given species; (2) it is now possible to calculate the interval of water contents in which non-orthodox oily seeds of a given species are likely to withstand LN exposure as a function of their lipid content.