Silene latifolia is a dioecious plant in which sex is determined by X and Y chromosomes. Expression of the B-function gene SLM2, an ortholog of PISTILLATA (PI) in Arabidopsis, was examined by in situ hybridization. SLM2 was not expressed in suppressed stamens of female flowers, but was expressed in developing stamens of smut-infected female flowers. These results indicate that the control of SLM2 is independent of the presence of the Y chromosome. Smut-infected females provide a useful system for clarifying the relationship between the B-function gene and the sex determination factor.
When the female plant of Silene latifolia is infected with the smut fungus Microbotryum violaceum, its rudimentary stamens develop into anthers which contain fungus teliospores instead of pollen. To identify genes required for maturation of anthers in S. latifolia, we performed a cDNA subtraction approach with healthy male buds and female buds infected with M. violaceum. We isolated five cDNA clones, which were preferentially expressed in healthy male buds during stages associated with a burst in tapetal activity. These five cDNAs are predicted to encode a mandelonitrile lyase protein (SlMDL1), a strictosidine synthase protein (SlSs), a glycosyl hydrolase 17 protein (SlGh17), a proline-rich protein APG precursor (SlAPG), and a chalcone-synthase-like protein (SlChs). All five genes showed expression in both healthy and fungus-infected male buds, but not expressed in either healthy or infected female buds. The first three genes were highly expressed in both tapetum and pollen grains while the last two genes were expressed only inside the tapetum of male flower buds. Phylogenetic analysis results showed that SlChs and SlGh17 belong to anther-specific subgroups of chalcone-synthase-like genes and glycosyl hydrolase 17 family genes, respectively. Our results suggest that the isolated five genes are related to the fertility of the anther leading to the development of fertile pollen. The smut fungus was not able to induce the expression of the five genes in the infected female buds. This raises the possibility that these genes are under the control of master gene(s) on the Y chromosome.
Background: Many drugs have been restricted in the treatment of gastric ulcers (GU). So, herbal medicines are now in great demand for their better cultural acceptability, compatibility, and minimal side effects. Therefore, our study aimed to assess the protective efficacy of Aloe vera gel and Geranium robertianum extracts against Aspirin®-induced GU in Wistar rats. Methods: Antioxidant activity and chemical composition of both herbs were analysed. Then, we divided forty female Wistar rats into five groups: a negative control group, a positive control group of Aspirin®-induced GU, and pretreated groups with Aloe Vera, geranium, and Famotidine (reference drug). The locomotor disability, anxiety-like behaviour, and ultrasonography were assessed. Ultimately, scarification of animals to determine gastric juice pH and ulcer index. Then the collection of stomach and liver for histopathological and immunohistochemical examinations, besides tracing the oxidative stress biomarkers and related genes. Results: High content of polyphenols was revealed in both extracts. The pretreatment with Aloe vera gel and geranium showed significant antioxidant activities with free radical scavenging and ferric-reducing power (FRAP). Moreover, they improved the stomach architecture and alleviated anxiety-like behaviour and motor deficits. They significantly reduced the expression of proinflammatory cytokine (TNF-α), inflammatory, and oxidative stress genes (NF-KB, HO-1, Nrf-2) while increasing the Keap-1 in gastric mucosa. Conclusion: Data presented a significant protective effect of Aloe vera gel and geranium against Aspirin®-induced GU; they reduced gastric mucosal injury with potential anxiolytic effects through their anti-inflammatory and antioxidant properties. Therefore, they may be considered promising agents for preventing or treating gastric ulceration.
Strain tolerance to toxic metabolites remains an important issue in the production of biofuels. Here we examined the impact of overexpressing the heterologous groESL chaperone from Clostridium acetobutylicum to enhance the tolerance of Escherichia coli against several stressors. Strain tolerance was identified using strain maximum specific growth rate (μ) and strain growth after a period of solvent exposure. In comparison with control strain, the groESL overexpressing strain yielded a 27 % increase in growth under 0.8 % (v/v) butanol, a 9 % increase under 1 % (v/v) butanol, and a 64 % increase under 1.75 (g/l) acetate. Moreover, after 10 h, groESL overexpression resulted in increase in relative tolerance of 58 % compared with control strain under 0.8 % (v/v) butanol, 56 % increase under 1 % (v/v) butanol, 42 % increase under 1 % (v/v) isobutanol, 36 % increase under 4 % (v/v) ethanol, 58 % increase under 1.75 (g/l) acetate. These data demonstrate that overexpression of the groESL from C. acetobutylicum in E. coli increased tolerance to several stressors. Solvent tolerant strain of E. coli was developed to be used as a basic strain for biofuel production.