Plant contents and quality of makhana (Euryale ferox)

Summary As a part of integrated study of makhana, the mineral contents of the plant parts and the fruits of makhana (Euryale ferox) have been presented here. It has been observed that the fruits were not only rich in minerals but also in protein. The plant parts also contained high amounts of micronutrients. Its fruits are, therefore, a good supplement for minerals which are produced from otherwise agriculturally waste (water-logged) areas.     

In vitro regeneration of Ruscus hypophyllum L. plants

Callus cultures were established from stem explants of Ruscus hypophyllum on a modified basal medium of Murashige and Skoog (1962) supplemented with 1 mg l^-1 2,4-D+0.1 mg l^-1 BAP. The optimal 2,4-D concentration for promoting shoot bud formation and growth was 0.05 mg l^-1 along with 0.5 mg l^-1 BAP. Sixty percent of rootless shoots produced flowers on the regenerating medium. Rooting was induced when shoots were transferred to half strength MS inorganic salts supplemented with 2 mg l^-1 IBA. Eighty percent of plants transferred to soil have survived.     

The effect of 2-deoxy-D-glucose on insulin release by neonatal rat B cells in culture

The culture for 7 days in medium with 5.5 mM glucose and 1 mM 2-deoxy-D-glucose enhanced the glucose sensitivity of neonatal rat B cells, and even stimulated their growth in vitro. Also, 2-deoxy-D-glucose supplementation maintained insulin release evoked by leucine and 2-ketoisocaproate from B cells at day 7 at levels several times higher than at day 1. The effect of leucine was greatly augmented by glutamine, whereas that of the 2-keto acid remained almost unchanged irrespective of the presence of glutamine. These results suggest an increase in oxidative catabolism of medium nutrients in B cells grown in medium with 2-deoxy-D-glucose for 7 days, and such metabolic changes may promote the growth of B cells in vitro.     

Effects of plant size on photosynthesis and water relations in the desert shrub Prosopis glandulosa (Fabaceae)

The Jornada del Muerto basin of the Chihuahuan Desert of southern New Mexico, USA, has undergone a marked transition of plant communities. Shrubs such as mesquite (Prosopis glandulosa) have greatly increased or now dominate in areas that were previously dominated by perennial grasses. The replacement of grasses by shrubs requires an establishment phase where small shrubs must compete directly with similar-sized grass plants. This is followed by a phase in which large, established shrubs sequester nutrients and water within their biomass and alter soil resources directly under their canopy, creating “islands” of fertility. We hypothesized that these two phases were associated with shrubs having different physiological response capacities related to their age or size and the resource structure of the environment. As a corollary, we hypothesized that responses of small shrubs would be more tightly coupled to variation in soil moisture availability compared to large shrubs. To test these hypotheses, we studied gas exchange and water relations of small (establishing) and large (established) shrubs growing in the Jornada del Muerto as a function of varying soil moisture during the season. The small shrubs had greater net assimilation, stomatal conductance, transpiration, and xylem water potential than large shrubs following high summer rainfall in July, and highest seasonal soil moisture at 0.3 m. High rates of carbon assimilation and water use would be an advantage for small shrubs competing with grasses when shallow soil moisture was plentiful. Large shrubs had greater net assimilation and water-use efficiency, and lower xylem water potential than small shrubs following a dry period in September, when soil moisture at 0.3 m was lowest. Low xylem water potentials and high water-use efficiency would allow large shrubs to continue acquiring and conserving water as soil moisture is depleted. Although the study provides evidence of differences in physiological responses of different-sized shrubs, there was not support for the hypothesis that small shrubs are more closely coupled to variation in soil moisture availability than large shrubs. Small shrubs may actually be less coupled to soil moisture than large shrubs, and thus avoid conditions when continued transpiration could not be matched by equivalent water uptake.     

PATTERNS IN LEAF MORPHOLOGY AND PHOTOSYNTHESIS IN SHOOTS OF SASSAFRAS ALBIDUM (LAURACEAE)

Trees of Sassafras albidum (Nuttall) Nees. display leaves that fall into discrete categories of form. Unlobed leaves, with undissected margins, predominate at proximal and distal nodes of shoots, while lobed leaves are most common at intermediate nodes. In this study we investigated the hypothesis that shoots of sassafras respond to environmental changes over the growing season by generating predictable nodal patterns for leaf morphology and physiology. We recorded leaf shape category and measured leaf surface area, node number, chlorophyll content, nitrogen content, and photosynthesis in four trees. Over 1,000 measurements of photosynthesis were made in situ, using the LI-Cor LI 6200 portable photosynthesis system. The two trees growing under heavy shade had few lobed leaves (2.0% and 18.8%) and often had negative carbon balance, with positive net photosynthesis occurring during sun flecks. The two trees growing in more open conditions had many more lobed leaves (56.3% and 61.0%) and higher, less variable net photosynthetic rates. As indicated by chlorophyll and nitrogen contents, the highest leaf photosynthetic rates occurred at intermediate nodes (nodes six to nine), and this was shifted distally along the shoot during the growing season. Leaves at intermediate nodes also had the largest surface areas and the greatest frequency of lobing. In comparative experiments with models, lobing was shown to enhance free-convectional heat loss relative to unlobed leaves of the same surface area. Due to their large surface area, these leaves also have the highest rates of whole leaf photosynthesis. Under conditions of equivalent photosynthetically active radiation, lobed leaves had higher rates of net photosynthesis than did unlobed leaves. We conclude that shoots of sassafras produce groups of leaves with predictably different morphological and physiological specializations.     

Rhizogenesis fromNigella sativa protoplasts

Summary Protoplasts were isolated for the first time from cell suspensions ofNigella sativa. These were then cultured in media and observed at regular intervals. Different concentrations of auxin and kinetin were tried with success to obtain root from the callus tissues of the protoplasts.     

RANBP2 and USP9x regulate nuclear import of adenovirus minor coat protein IIIa

As intracellular parasites, viruses exploit cellular proteins at every stage of infection. Adenovirus outbreaks are associated with severe acute respiratory illnesses and conjunctivitis, with no specific antiviral therapy available. An adenoviral vaccine based on human adenovirus species D (HAdV-D) is currently in use for COVID-19. Herein, we investigate host interactions of HAdV-D type 37 (HAdV-D37) protein IIIa (pIIIa), identified by affinity purification and mass spectrometry (AP-MS) screens. We demonstrate that viral pIIIa interacts with ubiquitin-specific protease 9x (USP9x) and Ran-binding protein 2 (RANBP2). USP9x binding did not invoke its signature deubiquitination function but rather deregulated pIIIa-RANBP2 interactions. In USP9x-knockout cells, viral genome replication and viral protein expression increased compared to wild type cells, supporting a host-favored mechanism for USP9x. Conversely, RANBP2-knock down reduced pIIIa transport to the nucleus, viral genome replication, and viral protein expression. Also, RANBP2-siRNA pretreated cells appeared to contain fewer mature viral particles. Transmission electron microscopy of USP9x-siRNA pretreated, virus-infected cells revealed larger than typical paracrystalline viral arrays. RANBP2-siRNA pretreatment led to the accumulation of defective assembly products at an early maturation stage. CRM1 nuclear export blockade by leptomycin B led to the retention of pIIIa within cell nuclei and hindered pIIIa-RANBP2 interactions. In-vitro binding analyses indicated that USP9x and RANBP2 bind to C-terminus of pIIIa amino acids 386–563 and 386–510, respectively. Surface plasmon resonance testing showed direct pIIIa interaction with recombinant USP9x and RANBP2 proteins, without competition. Using an alternative and genetically disparate adenovirus type (HAdV-C5), we show that the demonstrated pIIIa interaction is also important for a severe respiratory pathogen. Together, our results suggest that pIIIa hijacks RANBP2 for nuclear import and subsequent virion assembly. USP9x counteracts this interaction and negatively regulates virion synthesis. This analysis extends the scope of known adenovirus-host interactions and has potential implications in designing new antiviral therapeutics.     

Characterization of an exopolysaccharide produced by a marine Enterobacter cloacae

An exopolysaccharide producing marine bacterium, Enterobacter cloacae, was isolated from marine sediment collected from Gujarat coast, India. Chemical investigation of exopolysaccharide (EPS 71 a) revealed that this exopolysaccharide was an acidic polysaccliaride containing high amount of uronic acid, fucose and sulfate which is rare for bacterial exopolysaccharides. EPS 71a was found to have fucose, galactose, glucose and glucuronic acid in a molar ratio of 2: 1: 1: 1.     

Landscape genetics of a tropical rescue pollinator

Pollination services are increasingly threatened by the loss and modification of natural habitats, posing a risk to the maintenance of both native plant biodiversity and agricultural production. In order to safeguard pollination services, it is essential to examine the impacts of habitat degradation on the population dynamics of key pollinators and identify potential “rescue pollinators” capable of persisting in these human-altered landscapes. Using a landscape genetic approach, we assessed the impact of landscape structure on genetic differentiation in the widely-distributed tropical stingless bee Trigona spinipes (Apidae: Meliponini) across agricultural landscape mosaics composed of coffee plantations and Atlantic forest fragments in southeastern Brazil. We genotyped 115 bees at 16 specific and highly polymorphic microsatellite loci, developed using next-generation sequencing. Our results reveal that T. spinipes is capable of dispersing across remarkably long distances, as we did not find genetic differentiation across a 200 km range, nor fine-scale spatial genetic structure. Furthermore, gene flow was not affected by forest cover, land cover, or elevation, indicating that reproductive individuals are able to disperse well through agricultural landscapes and across altitudinal gradients. We also found evidence of a recent population expansion, suggesting that this opportunistic stingless bee is capable of colonizing degraded habitats. Our results thus suggest that T. spinipes can persist in heavily-altered landscapes and can be regarded as a rescue pollinator, potentially compensating for the decline of other native pollinators in degraded tropical landscapes.