Dynamics of abscisic acid (ABA) and indole-3-acetic acid (IAA) contents were followed in developing barley caryopses of the ABA-deficient mutant AZ34 and its parental cultivar Steptoe. Distribution of these hormones and HvPIP2 aquaporins (AQPs) was studied with the help of immunohistochemical methods in the roots and coleorhiza of developing embryos. In Steptoe, maturation of the caryopsis was accompanied by vast accumulation of ABA, while this hormone accumulated more slowly in the caryopsis of AZ34 and its content was lower than in Steptoe. Accumulation of ABA was accompanied by a decline in IAA level in the developing caryopsis, the process being delayed in AZ34 in accordance with the slower accumulation of ABA. ABA accumulated to high levels in the coleorhiza cells of Steptoe, while the effect was absent in AZ34. The high level of ABA was likely to be important for maintaining the barrier function of the coleorhiza, preventing germination of seminal roots and enabling seed dormancy, while the absence of ABA accumulation in coleorhiza of AZ34 may be responsible for the initiation of root germination inside the caryopsis. The abundance of HvPIP2 AQPs in the seminal roots was higher at the beginning of maturation of Steptoe caryopsis and declined afterwards, while the levels of APQs increased later in AZ34 in accordance with the delay in ABA accumulation. These results suggest the importance of ABA accumulation in coleorhiza for preventing precocious growth of seminal roots, and suggest regulation of IAA and aquaporin levels by this hormone during maturation of embryos.

The objectives were to develop an effective protocol for transfection of ovine secondary follicles and to assess the effect of attenuating aquaporin 3 (AQP3) using a small interfering RNA (siRNA-AQP3) on antrum formation and follicular growth in vitro. Various combinations of Lipofectamine® volumes (0.5, 0.75 or 1.0 µl), fluorescent oligonucleotide (BLOCK-iT ™) concentrations (3.18, 27.12 or 36.16 nM) and exposure times (12, 14, 16, 18 or 20 h) were tested. The BLOCK-iT™ was replaced by siRNA-AQP3 in the transfection complex. Ovine secondary follicles were isolated and cultured in vitro for 6 days using standard protocols. Follicles were transfected on day 0 or 3 or on both days (0 and 3) and then cultured for an additional 3 or 6 days. As revealed by the fluorescence signal, the Lipofectamine®/BLOCK-iT™ complex (0.75 µl + 27.12 nM by 12 h of incubation) crossed the basement membrane and granulosa cell and reached the oocytes. In general, the rate of intact follicles was higher and the rate of antrum formation was lower in transfected follicles compared with control follicles. In conclusion, ovine secondary follicles can be successfully transfected during in vitro culture, and siRNA-mediated attenuation of AQP3 gene reduced antrum formation of secondary follicles.

Drought represents one of the major constraints on agricultural productivity and food security and in future is destined to spread widely as a consequence of climate change. Research efforts are focused on developing strategies to make crops more resilient and to mitigate the effects of stress on crop production. In this context, the use of root-associated microbial communities and chemical priming strategies able to improve plant tolerance to abiotic stresses, including drought, have attracted increasing attention in recent years. The current review offers an overview of recent research aimed at verifying the role of arbuscular mycorrhizal fungi and chemical agents to improve plant tolerance to drought and to highlight the mechanisms involved in this improvement. Attention will be devoted mainly to current knowledge on the mechanisms involved in water transport.

Aquaporin (SmAQP) is the most abundant transmembrane protein in the tegument of Schistosoma mansoni. This protein is expressed in all developmental stages and seems to be essential in parasite survival since it plays a crucial role in osmoregulation, nutrient transport and drug uptake. In this study, we utilized the murine model to evaluate whether this protein was able to induce protection against challenge infection with S. mansoni cercariae. A chimeric (c) SmAQP was formulated with Freund's adjuvant for vaccination trial and evaluation of the host's immune response was performed. Our results demonstrated that immunization with cSmAQP induced the production of high levels of specific anti-cSmAQP IgG antibodies and a Th1/Th17 type of immune response characterized by IFN-γ, TNF-α and IL-17 cytokines. However, vaccination of mice with cSmAQP failed to reduce S. mansoni worm burden and liver pathology. Finally, we were unable to detect humoral immune response anti-cSmAQP in the sera of S. mansoni-infected human patients. Our results lead us to believe that SmAQP, as formulated in this study, may not be a good target in the search for an anti-schistosomiasis vaccine.

The factual evidence for aquaporins, the constituents of water channels in cell membranes and operation of water channels is reviewed in developing, maturing and germinating seeds.

Disentangling the neuroendocrine systems that regulate energy homeostasis and adiposity has been a long-standing challenge in pathophysiology, with obesity being an increasingly important public health problem. Adipose tissue is no longer considered a passive bystander in body-weight regulation. It actively secretes a large number of hormones, growth factors, enzymes, cytokines, complement factors and matrix proteins, at the same time as expressing receptors for most of these elements, which influence fuel storage, mobilisation and utilisation at both central and peripheral sites. Thus, an extensive cross talk at a local and systemic level in response to specific external stimuli or metabolic changes underpins the multifunctional characteristics of adipose tissue. In addition to the already-known adipokines, such as IL, TNFα, leptin, resistin and adiponectin, more recently attention has been devoted to ‘newcomers’ to the ‘adipose tissue arena’, which include aquaporin, caveolin, visfatin, serum amyloid A and vascular endothelial growth factor. While in vitro and in vivo experiments have provided extremely valuable information, the advances in genomics, proteomics and metabolomics are offering a level of information not previously attainable to help unlock the molecular basis of obesity. The potential and power of combining pathophysiological observations with the wealth of information provided by the human genome, knock-out models, transgenesis, DNA microarrays, RNA silencing and other emerging technologies offer a new and unprecedented view of a complex disease, conferring novel insights into old questions by identifying new pieces to the unfinished jigsaw puzzle of obesity.

The salivary glands are the organs of osmoregulation in ticks and, as such, are critical to the biological success of ticks both during the extended period off the host and also during the feeding period on the host. Absorption of water vapour from unsaturated air into hygroscopic fluid produced by the salivary glands permit the tick to remain hydrated and viable during the many months between blood-meals. When feeding, the tick is able to return about 70% of the fluid and ion content of the blood-meal into the host by salivation into the feeding site. This saliva also contains many bioactive protein and lipid components that aid acquisition of the blood-meal. The salivary glands are the site of pathogen development and the saliva the route of transmission. The importance of the multifunctional salivary glands to tick survival and vector competency makes the glands a potential target for intervention. Here we review the cell biology of tick salivary glands and discuss the application of new approaches such as expressed sequence tag projects and RNA interference to this important area in the field of tick and tick-borne pathogen research.

The paucity of detailed X-ray crystallographic structures of integral membrane proteins arises from substantive technical obstacles in the overexpression of multimilligram quantities of protein, and in the crystallization of purified protein-detergent complexes (PDCs). With rare exception, crystal contacts within the lattice are mediated by protein–protein interaction, and the detergent surrounding the protein behaves as a disordered solvent. The addition and use of surfactants that display mesoscopic self-assembly behavior in membrane protein crystallization experiments presents a novel alternative strategy. Well-ordered crystals of the water channel human aquaporin-1 (hAQP1) that diffract to 4 Å resolution have been obtained with this approach.