The Exploitation of Nematode-Responsive Plant Genes in Novel Nematode Control Methods

The molecular interactions between plants and sedentary nematodes are undergoing intense study, not only for reasons of fundamental research but also for the potential benefits to agriculture. The present technology allows the transformation of an increasing number of crop plants, providing new ways to introduce resistance against plant-parasitic nematodes. The ability of sedentary nematodes to induce specialized feeding sites in plant roots is one of the most fascinating aspects of this host–parasite interaction. Molecular approaches have been initiated to identify and characterize plant genes altered in expression after infection by sedentary nematodes. The results obtained indicate that many genes indeed become up-regulated upon nematode infection. Surprisingly, several so-called constitutive promoters that are normally used to achieve high expression in plant cells are completely ‘silenced’ in the feeding sites within days after nematode infection. Generally, there are two options available for the genetic engineering of nematode resistance: the synthesis of anti-nematode proteins or the localized production of a cytotoxic protein that interferes with the development of feeding cells. Nematode-induced promoters are very useful for the production by plants of sufficiently high levels of anti-nematode proteins at feeding sites. Alternatively, interfering with feeding-cell development is somewhat similar to the hypersensitive response evoked by nematodes in a naturally resistant plant. Here, destruction of specific plant cells can be achieved by the localized expression of a cytotoxin such as barnase, a potent ribonuclease. This approach, however, calls for a highly specific ‘non-leaky’ promoter, which is active only in the feeding cells. Another possibility is to use a two-component system, where the leakiness of the promoter in other tissues is counterbalanced by the constitutive expression of a neutralizing gene.     

Similar developmental fluctuations of hepato-renal xanthine oxidoreductase gene expression and xanthine oxidase activity in layer and broiler chicken embryos

1. Xanthine oxidase (XO) has many physiological functions associated with the synthesis of both antioxidant (uric acid: UA) and numerous oxidants (e.g. H₂O₂), which makes it an important regulator of the cellular redox potential involving organogenesis. The ontogenetic study of hepatic and renal XO makes a better understanding of the putative role of this enzyme in the development of these tissues.

2. Developmental changes of gene expression of xanthine oxidoreductase (XOR), XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos were examined during incubation d 14–21.

3. In both strains, hepatic XOR gene expression peaked on d 21 while renal XOR gene expression did not change.

4. The XO activity was higher in kidney than liver in both strains. Hepatic XO activity of both strains peaked on d 18 and thereafter was decreased on d 21. Renal XO activity peaked on d 18 and from then on did not show any significant changes until d 21 in both strains.

5. The UA content was higher in kidney vs. liver in both strains. The hepatic and renal UA values of the both strains increased significantly from d 14 to d 21.

6. The present results showed dissimilar behaviour of XOR gene expression, XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos.     

Integrated pest management of Tuta absoluta: practical implementations across different world regions

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...     

Total Oxidative status of Mouse Vitrified Pre-Antral Follicles with Pre-Treatment of Alpha Lipoic Acid

Background: Cryopreservation of pre-antral follicles is a hopeful technique to preserve female fertility. The aim of the present study was to evaluate reactive oxygen species (ROS) and total antioxidant capacity (TAC) levels of mouse vitrified pre-antral follicles in the presence of alpha lipoic acid (ALA). Methods: Isolated pre-antral follicles (140–150 µm in diameter) were divided into vitrified–warmed and fresh groups. Each group was subjected to in vitro maturation with or without ALA for 12 days, followed by adding human chronic gonadotropin to induce ovulation. In vitro fertilization was performed to evaluate their developmental competence. In parallel, the amount of ROS and TAC were assessed after 0, 24, 48, 72, and 96 h of culture by 2'',7''-dichlorofluorescin assay and ferric reducing/antioxidant power assay, respectively. Results: The respective rates of survival, antrum formation, and metaphase II oocytes were significantly higher in ALA-supplemented groups compared to the groups not treated with ALA. TAC and ROS levels were significantly decreased and increased, respectively during the culture period up to 96 h in the absence of ALA in both vitrified and non-vitrified samples. However, with pretreatment of ALA, TAC levels were increased significantly and remained constant up to 96 h in vitrified-warmed pre-antral follicles, while ROS levels completely returned to the level of starting point after 96 h of culture in the presence of ALA. Conclusion: Pretreatment of ALA positively influences development of pre-antral follicles in vitrified and non-vitrified samples through increasing follicular TAC level and decreasing ROS levels. Key Words: Vitrification, Pre-antral follicle, Alpha lipoic acid (ALA), Reactive oxygen species (ROS), Total antioxidant capacity (TAC)     

Evaluation of bermuda and paspalum grass types for urban landscapes under saline water irrigation

In the arid regions, turfgrass cover is an integral part of landscape to protect the soil from erosion, enhance the aesthetic value, and improve the microclimate. The salinity and the scarcity of fresh water of the arid region are the major challenging factors in turfgrass production. Therefore, the need for salt tolerant turfgrass with functional quality is necessary to improve the turf performance. The detrimental effects of salinity include growth suppression, and lowered osmotic potential ultimately leading to firing of the leaf blades. In this context, the study was undertaken to determine the relative salt tolerance and growth response of turfgrass genotypes in order to recommend turfgrass cultivars that can tolerate high salinity irrigation and maintain excellent visual and functional qualities under United Arab Emirates (UAE) condition. The paspalum cultivars maintained the highest succulence percentage compared to the bermudagrass cultivars under enhanced salinity levels. The shoots count, fresh weight (FW), and dry weight (DW) were found highest in paspalum types. The chlorophyll a, chlorophyll b and the total chlorophyll content was found higher in bermuda grass types under high salinity levels. The bermudagrass cultivars showed significantly higher carotenoids, anthocyanins and proline compared to the paspalum types under salt stress condition. In the case of princess 77 and Yukon, an inherently high amount of proline was recorded which confirmed an increase up to 10,000 ppm and drastically declined beyond this concentration. Sea Dwarf paspalum and Sea Isle 2000 maintained uniformity in the proline level at all levels of salinity without significant variation. These findings point to the fact that both paspalum and bermuda types exhibited varied responses to different physiological and biochemical parameters under the saline conditions. Paspalum types have an edge over the bermudagrass in terms of shoot density, which is a potential factor in determining the high-quality turfs. Bermudagrass types can be applied in lower salinity conditions based on the responses as evidenced from the present results.     

Structure of Vomeronasal Organ (Jacobson organ) in Male Camelus Domesticus Var. dromedaris persica

The vomeronasal organ (VNO) is a tubular structure in the roof of nasal cavity. The important role of this organ is olfaction of sexual odour. In this study, position, anatomical structure and histology of VNO in Iranian camels (camelus domesticus var. dromedaris persica) were determined. Fourteen healthy male camel heads were collected from an industrial slaughterhouse in Tehran, Iran, for anatomical and histological studies (seven each). The length of VNO and width of dental pad and the number and width of palatine crests were measured. For anatomical studies, the mandible was removed, and maxilla and nasal cavity was cut longitudinally and transversely. For histological studies, the mandible was removed, and first 0.5 cm of initial part of VNO was cut. Then, nasal cavity was cut in some segments with 2 cm thickness. The width of VNO was 3.85 ± 0.31 cm and 1.57 ± 0.18 cm in front and distal parts, respectively. The length of VNO was 15.61 ± 0.59 cm. In histological examinations, VNO was surrounded by J‐shape hyaline cartilage. The lining epithelium of lateral wall of VNO was originated from respiratory epithelium, while it had an olfactory epithelium origin in the medial wall. Lamina propria and tunica submucosa were a cavernous connective tissue with seromucous gland with abundant of serous secretory units. The lumen of VNO opens into nasal cavity. The presence of olfactory epithelium found in our study indicates an important role for VNO in pheromone perception and beginning of sexual behaviour.     

Improvement of Tissue Survival of Skin Flaps by 5α-Reductase Inhibitors: Possible Involvement of Nitric Oxide and Inducible Nitric Oxide Synthase

Background:

Skin flap grafting is a popular approach for reconstruction of critical skin and underlying soft tissue injuries. In a previous study, we demonstrated the beneficial effects of two 5α-reductase inhibitors, azelaic acid and finasteride, on tissue survival in a rat model of skin flap grafting. In the current study, we investigated the involvement of nitric oxide and inducible nitric oxide synthase (iNOS) in graft survival mediated by these agents.

Methods:

A number of 42 male rats were randomly allocated into six groups: 1, normal saline topical application; 2, azelaic acid (100 mg/flap); 3, finasteride (1 mg/flap); 4, injection of L-N^G-nitroarginine methyl ester (L-NAME) (i.p., 20 mg/kg); 5, L-NAME (20 mg/kg, i.p.) + azelaic acid (100 mg/flap, topical); 6, L-NAME (20 mg/kg, i.p.) + finasteride (1 mg/flap, topical). Tissue survival, level of nitric oxide, and iNOS expression in groups were measured.

Results:

Our data revealed that azelaic acid and finasteride significantly increased the expression of iNOS protein and nitric oxide (NO) levels in graft tissue (P < 0.05). These increases in iNOS expression and NO level were associated with higher survival of the graft tissue.

Conclusion:

It appears that alterations of the NO metabolism are implicated in the azelaic acid- and finasteride-mediated survival of the skin flaps.Key Words: Finasteride, Azelaic acid, Surgical flaps, Nitric oxide, Nitric oxide synthase Type II     

Formation of a Reservoir of Sperm in the Oviduct

A reservoir of sperm in the initial segment of the oviduct has been found in several species of domestic and laboratory mammals. Evidently, the reservoir serves to ensure successful fertilization by providing the appropriate number of sperm in the appropriate physiological state for fertilizing oocytes soon after they enter the oviduct. Recent evidence indicates that sperm are trapped in the reservoir by binding to specific carbohydrate moieties on the surface of the mucosal epithelium of the oviduct. A bovine seminal plasma protein has been identified that associates with sperm and confers on them the capacity to bind to the carbohydrate moiety.