Interaction between PGPR and PGR for water conservation and plant growth attributes under drought condition

Drought is one of the key restraints to agricultural productivity worldwide and is expected to increase further. Drought stress accompanied by reduction in precipitation pose major challenges to future food safety. Strategies should be develop to enhance drought tolerance in crops like chickpea and wheat, in order to enhance their growth and yield. Drought tolerance strategies are costly and time consuming however, recent studies specify that plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGRs) can help plants to withstand under harsh environmental condition and enable plants to cope with drought stress. PGPR can act as biofertilizer and bioenhancer for different legumes and non-legumes. The use of PGPR and symbiotic microorganisms, may be valuable in developing strategies to assist water conservation in plants. The use of PGPR has been confirmed to be an ecologically sound way of enhancing crop yields by facilitating plant growth through direct or indirect mechanism. The mechanisms of PGPR for water conservation include secretion of exopolysaccharides, biofilm formation, alternation in phytohormone content, improvement in sugar concentration, enhancing availability of micro- and macronutrients and changes in plant functional traits. Similarly, plant growth regulators (PGRs) are specially noticed in actively growing tissues under stress conditions and have been associated in the control of cell division, embryogenesis, root formation, fruit development and ripening, and reactions to biotic and abiotic stresses and upholding water conservation status in plants. Previous studies also suggest that plant metabolites interact with plant physiology under stress condition and impart drought tolerance. Metabolites like, sugars, amino acids, organic acid and polyols play a key role in drought tolerance of crop plants grown under stress condition. It is concluded from the present study that PGRs in combination with PGPR consortium can be an effective formulation to promote plant growth and maintenance of plant turgidity under drought stress. This review is a compilation of the effect of drought stress on crop plants and described interactions between PGPR/PGRs and plant development, knowledge of water conservation and stress release strategies of PGPR and PGRs and the role of plant metabolites in drought tolerance of crop plants. This review also bridges the gaps that summarizes the mechanism of action of PGPR for drought tolerance of crop plants and sustainability of agriculture and applicability of these beneficial rhizobacteria in different agro-ecosystems under drought stress.     

Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) hydraulic conductivity links to leaf venation architecture under well-watered condition rather than PEG-induced water deficit

Higher plant hydraulic conductivity (K _plant) is vital for plant growth, especially under PEG-induced water deficit stress (PEG-IWDS). Leaf venation architecture is a key determinant of leaf hydraulic conductivity (K _leaf) and K _leaf is a major component of K _plant across different plant species. However, there is little information about (1) varietal difference in leaf vein development in cereal crops, such as rice plants; (2) the effects of PEG-IWDS on leaf vein development; (3) the coordination between leaf venation architecture and K _plant as well as K _leaf under PEG-IWDS. In the present study, widely cultivated eight rice cultivars were grown hydroponically under well-watered condition (WWC) and PEG-IWDS, simulated by adding 15 % (w/v) PEG6000. Leaf venation architecture, including total longitudinal leaf vein number, leaf vein numbers per unit width (LVNW), vein thickness and leaf mass per area, as well as K _plant and K _leaf were measured to address above-mentioned questions. The results showed that leaf venation architecture exhibited significant varietal differences and PEG-IWDS significantly increased LVNW while decreased vein thickness. PEG-IWDS suppressed both K _plant and K _leaf but the decrease was much higher in K _plant than K _leaf. There was a significant and positive correlation observed between LVNW and K _leaf under both WWC and PEG-IWDS but the correlation between LVNW and K _plant was only significant under WWC. K _leaf was significantly and positively correlated with K _plant under WWC but not under PEG-IWDS. It is concluded that K _leaf is a major determinant for K _plant under WWC but not under PEG-IWDS; therefore, breeding or selecting rice cultivars with high LVNW can improve shoot water supplement under WWC but not under PEG-IWDS condition.     

Kinetics and Molecular Docking Study of an Anti-diabetic Drug Glimepiride as Acetylcholinesterase Inhibitor: Implication for Alzheimer’s Disease-Diabetes Dual Therapy

Neurochemical Research - At the present time, treatment of two most common degenerative disorders of elderly population i.e., Type 2 Diabetes Mellitus (T2DM) and Alzheimer’s disease (AD) is a...     

Rapid Detection of Ophiostoma piceae and O. quercus in Stained Wood by PCR

A rapid, sensitive, and simple method was developed to detect the sapstain fungi Ophiostoma piceae and O. quercus in stained wood. By using microwave heating for DNA extraction and PCR with internal transcribed spacer-derived-specific primers, detection was feasible within 4 h, even with DNA obtained from a single synnema. This method can easily be extended for the detection of other wood-inhabiting fungi.     

Investigation of karyotypic composition and evolution in <Emphasis Type="Italic">Lilium</Emphasis> species belonging to the section martagon

Analyzing chromosomal traits is one of the pragmatic ways to establish evolutionary and genetic database of plants that has complicated phylogenetic system. There are some conflicts on the exact phylogeny and evolutionary pathway of Lilium, and section martagon is the most complicated part among them. In this study, chromosomal traits of martagon lily species are described. All martagon lilies were analyzed with FISH (Fluorescence in situ hybridization) technique, followed by detailed karyotyping. Each species showed 2n = 2x = 24 of chromosome complement. Size of chromosomes ranged from 451.04 to 680.06 µm. 5S and 45S ribosomal DNA, general molecular markers in modern evolutionary research were used as probe in this study. Variation in rDNA loci and chromosome translocation were observed in Lilium hansonii; the highest number of 45S rDNA loci was detected in Lilium hansonii, followed by other martagon lilies, in similar locations but with differences, and chromosome translocation was observed from one individual of Lilium hansonii. Additionally, Lilium tsingtauense from Jeju-do Island, Korea was detected with two extra chromosomes. These kind of genetic variations through karyotyping indicate ongoing genetic variations in martagon lilies. In this study, precise analysis of chromosome traits in Lilium species belonging to section martagonperformed to contribute to better comprehension of the evolutionary pathway and establishment of cytogenetic database for further plant breeding research.     

Effects of ferrous iron on the performance and microbial community in aerobic granular sludge in relation to nutrient removal

Lab‐scale experiments were conducted to investigate the effects of ferrous iron on nutrient removal performance and variations in the microbial community inside aerobic granular sludge for 408 days. Two reactors were simultaneously operated, one without added ferrous iron (SBR1), and one with 10 mg Fe²⁺ L^?1 of added ferrous iron (SBR2). A total of 1 mg Fe²⁺ L^?1 of added ferrous iron was applied to SBR1 starting from the 191st day to observe the resulting variations in the nutrient removal performance and the microbial community. The results show that ammonia‐oxidizing bacteria (AOB) could not oxidize ammonia due to a lack of iron compounds, but they could survive in the aerobic granular sludge. Limited ferrous iron addition encouraged nitrification. Enhanced biological phosphorus removal (EBPR) from both reactors could not be maintained regardless of the amount of ferrous iron that was applied. EBPR was established in both reactors when the concentration of mixed liquor suspended solid (MLSS) and the percentage of Accumulibacteria increased. A total of 10 mg Fe²⁺ L^?1 of added ferrous iron had a relatively adverse effect on the growth of AOB species compared to 1 mg Fe²⁺ L^?1 of added ferrous iron, but it encouraged the growth of Nitrospira sp. and Accumulibacteria, which requires further study. It could be said that the compact and stable structure of aerobic granular sludge preserved AOB and NOB from Fe‐deficient conditions, and wash‐out during the disintegration period. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:716–725, 2017     

Selection for social signalling drives the evolution of chameleon colour change

Rapid colour change is a remarkable natural phenomenon that has evolved in several vertebrate and invertebrate lineages. The two principal explanations for the evolution of this adaptive strategy are (1) natural selection for crypsis (camouflage) against a range of different backgrounds and (2) selection for conspicuous social signals that maximise detectability to conspecifics, yet minimise exposure to predators because they are only briefly displayed. Here we show that evolutionary shifts in capacity for colour change in southern African dwarf chameleons (Bradypodion spp.) are associated with increasingly conspicuous signals used in male contests and courtship. To the chameleon visual system, species showing the most dramatic colour change display social signals that contrast most against the environmental background and amongst adjacent body regions. We found no evidence for the crypsis hypothesis, a finding reinforced by visual models of how both chameleons and their avian predators perceive chameleon colour variation. Instead, our results suggest that selection for conspicuous social signals drives the evolution of colour change in this system, supporting the view that transitory display traits should be under strong selection for signal detectability.     

Effects of eCG and FSH on ovarian response, recovery rate and number and quality of oocytes obtained by ovum pick-up in Holstein cows

The goal of the present study was to compare the ovarian response, oocyte yields per animal, and the morphological quality of oocytes collected by ultrasound guided follicular aspiration from Holstein cows treated either with FSH or eCG. Twenty four normal cyclic, German Holstein cows were randomly divided into two groups. Fourteen cows received 3000 IU eCG on day-4 prior to ovum pick-up (OPU) (day 0), 2 days later (day-2), 625 microg cloprostenol was administered. On day-1 GnRH was administered i.m. and 24h later OPU (day 0) was performed. In ten cows a total dose of 500 IU follicle stimulating hormone (Pluset) was administered intramuscularly in a constant dosage for 4 days with intervals of 12h, starting on day-5. Luteolysis was induced by application of 625 microg cloprostenol on day-2. On day-1 (24h after the last FSH treatment) GnRH was administered i.m. and 24h later OPU (day 0) was performed. Ovarian follicles were visualized on the ultrasound monitor, counted and recorded. All visible antral follicles were punctured. Recovered oocytes were graded morphologically based on the cumulus investment. Average follicle number in ovaries was higher in FSH group than eCG group (p<0.05). Oocyte yields per animal did not differ between FSH and eCG groups. The proportion of grade A oocytes was higher in the FSH group in the than eCG group (p<0.05). Likewise, rate of grade C oocytes in FSH group were lower than eCG group (p<0.05). In conclusion, these results suggest that ovarian response, follicle number in ovaries and oocyte quality are affected by the type of gonadotropin and FSH is better alternative than eCG for OPU treatment.     

Furoquinoline alkaloids of Ertela (Monnieria) trifolia (L.) Kuntze from the Suriname rainforest

7-(2'-Hydroxy-3'-chloroprenyloxy)-4,8-dimethoxyfuroquinoline (1) and 6-(2'-hydroxy-3'-chloroprenyloxy)-4,7-dimethoxyfuroquinoline (2), together with ten known compounds, have been isolated from the aerial parts of Ertela (Monnieria) trifolia (L.) Kuntze. All the isolates were tested for antiproliferative activity against the A2780 human ovarian cancer cell line.     

PuraMatrix Encapsulation of Cancer Cells

Increasing evidence suggests that culturing cancer cells in three dimensions more accurately recapitulates the complexity of tumor biology. Many of these models utilize reconstituted basement membrane derived from animals which contain a variable amount of growth factors and cytokines that can influence the growth of these cell culture models. Here, we describe in detail the preparation and use of PuraMatrix, a commercially available self assembling peptide gel that is devoid of animal-derived material and pathogens to encapsulate and propagate the ovarian cancer cell line, OVCAR-5. We begin by describing how to prepare the PuraMatrix prior to use. Next, we demonstrate how to properly mix the PuraMatrix and cell suspension to encapsulate the cells in the hydrogel. Upon the addition of cell culture media or injection into a physiological environment, the peptide component of PuraMatrix rapidly self assembles into a 3D hydrogel that exhibits a nanometer scale fibrous structure with an average pore size of 5-200 nm¹. In addition, we demonstrate how to propagate cultures grown in encapsulated PuraMatrix. When encapsulated in PuraMatrix, OVCAR-5 cells assemble into three dimensional acinar structures that more closely resemble the morphology of micrometastatic nodules observed in the clinic than monolayer in vitro models. Using confocal microscopy we illustrate the appearance of representative OVCAR-5 cells encapsulated in PuraMatrix on day 1, 3, 5, and 7 post plating. The use of PuraMatrix to culture cancer cells should improve our understanding of the disease and allow us to assess treatment response in more clinically predictive model systems.Download video file.^{(85M, mp4)}