Iron (Fe) is an essential mineral element that governs the composition of natural plant communities and limits crop yield in agricultural ecosystems due to its extremely low availability in most soils, particularly at alkaline pH. To extract sufficient Fe from the soil under such conditions, some plants, including Arabidopsis (Arabidopsis thaliana), secrete Fe-mobilizing phenylpropanoids, which mobilize sparingly soluble Fe hydroxides by reduction and chelation. We show here that ectopic expression of the IRONMAN peptides IMA1 and IMA2 improves growth on calcareous soil by inducing biosynthesis and secretion of the catecholic coumarin fraxetin (7,8-dihydroxy-6-methoxycoumarin) via increased expression of MYB72 and SCOPOLETIN 8-HYDROXYLASE (S8H), a response that is strictly dependent on elevated environmental pH (pHe). By contrast, transcription of the cytochrome P450 family protein CYP82C4, which catalyzes the subsequent hydroxylation of fraxetin to sideretin, which forms less stable complexes with Fe, was strongly repressed under such conditions. We concluded that IMA peptides regulate processes supporting Fe uptake at both acidic and elevated pH by controlling gene expression upstream of or in concert with a putative pHe signal, adapting the plant to prevailing edaphic conditions. This regulatory pattern confers tolerance to calcareous soils by extending the pH range in which Fe can be efficiently absorbed from the soil. Our results further suggest that pHe calibrates the activities of components of the Fe deficiency response, accentuating processes that are most efficient under the prevailing conditions. Altering the expression of IMA peptides provides a route for generating plants adapted to calcareous soils.

Background:Agaricus bisporus is an edible basidiomycete fungus. Both the body and the mycelium contain compounds comprising a wide range of antimicrobial molecules, contributing in improvement of immunity and tumor-retardation. Objectives: The presence of endophytes capable of producing bioactive compounds was investigated in Agaricus bisporus. Materials and Methods: Endophytes from Agaricus bisporus was isolated on LB agar. The obtained isolates were characterized morphologically and biochemically. Further 16S rRNA sequencing was implemented for molecular analysis of isolates. The isolate was mass produced and the bioactive compounds were extracted using ethyl acetate, chloroform and hexane. Agar well diffusion method was carried out to seek the potential of any antimicrobial activity of the crude bioactive compounds against known pathogens. GC-MS and FT-IR analysis were performed for the identification of bioactive compounds. Results: VIT-CMJ2 was identified as Enterobacter sp. as revealed by 16S rRNA sequencing. Chloroform extract of VIT-CMJ2 showed a maximum zone of inhibition of 19 mm against Salmonella typhi followed by hexane and ethyl acetate extracts. The GC-MS analysis revealed the presence of several bioactive compounds having effective antimicrobial activity like butyl ester, Behenicalcohol, S , S-dioxide derivatives and some others which were later confirmed by FT-IR spectral stretches.Conclusions: The present study shows the insight on the way endophytes interact with Agaricus bisporus; thereby improving the nutritional profile.

The intestine of adult indigenous goat of Assam (Capra hircus) was studied by scanning electron microscopy (SEM) for elucidating the morphology of intestinal mucosa as well as the morphology of gutassociated lymphoid tissue including Peyer's patches (PP) and solitary lymphoid nodule. SEM of intestines revealed the presence of villi in the small intestinal mucosa. Goblet cells were noticed as white pinheads on the villus surface between the enterocytes. The large intestinal mucosa of adult Assam local goat was devoid of villi. SEM of small intestinal mucosa revealed leaf or finger-like absorptive villi covering PP. Even the dome villi were completely covered by absorptive villi and were shorter than the absorptive villi. The absorptive villi in all segments of the small intestine had numerous microvilli. The interfollicular region had high endothelial venules. Propria nodules were lymphoid nodules predominantly in lamina propria and covered by distinct follicle-associated epithelium which lacked goblet cells and openings to deep invaginations into the mucosa.Keywords: Goat, gut-associated lymphoid tissue, intestine, scanning electron microscopy, villi.SCANNING electron microscopic studies on intestinal mucosa and gut-associated lymphoid tissue (GALT) have been conducted by several researchers like Mebus et al. 1 in gnotobiotic calf; Cormack 2 in human and mouse; Wile and Nakov 3 in horse; Wile 4 in ox, sheep and goat. However, such studies on the intestine and GALT of goat are meagre. In the present study, intestine of adult indigenous goat of Assam (Capra hircus) was studied by scanning electron microscopy (SEM) for elucidating the morphological characteristics of intestinal mucosa and GALT including the Peyer's patches (PP) and the solitary lymphoid nodule (SLN). The study, therefore, would contribute to further research on the GALT of herbivores.The intestines were procured from local slaughter houses after careful observation of the slaughtered animals. Representative tissue samples were collected from all segments of small and large intestines. From each segment, samples were obtained from cranial, middle and caudal parts. The samples were preserved in 2% glutaraldehyde solution in 0.1 M cacodylate buffer and processed for SEM 5 and were examined in JMS-35(CF) Joel scanning electron microscope operated at 20 kV at the Sophisticated Analytical Instrument Facility, North Eastern Hill University (NEHU), Shillong, India.The SEM of intestines of adult goat revealed the presence of villi in the small intestinal mucosal surface. The villi were mostly finger-like with variable size and shape depending upon area. The duodenal villi, especially in the proximal part were mostly leaf-like and broader, whereas the villi of distal duodenum, jejunum and ileum were finger-like, longer and slender (Figures 1 and 2). Microvilli were seen on the villus surface and the cores of villi were made up of lamina propria (Figure 3). Similar observations were reported by Cormack 2 in human small intestine where variations in villi...

Iron (Fe) is an essential mineral element which governs the composition of natural plant communities and limits crop yield in agricultural ecosystems due to its extremely low availability in most soils, particularly at alkaline pH. To extract sufficient Fe from the soil under such conditions, some plants including Arabidopsis thaliana secrete Fe-mobilizing phenylpropanoids, which mobilize sparingly soluble Fe hydroxides by reduction and chelation. We show here that ectopic expression of the IRONMAN peptides IMA1 and IMA2 improves growth on calcareous soil by inducing the biosynthesis and secretion of the catecholic coumarin fraxetin (7,8-dihydroxy-6-methoxycoumarin) through increased expression of MYB72 and SCOPOLETIN 8-HYDROXYLASE (S8H), a response which is strictly dependent on elevated environmental pH (pHe). By contrast, transcription of the cytochrome P450 family protein CYP82C4, catalyzing the subsequent hydroxylation of fraxetin to sideretin, which forms less stable complexes with iron, was strongly repressed under such conditions. Luciferase reporter assays in transiently transformed protoplasts showed that IMA1/IMA2 peptides are translated and modulate the expression of CYP82C4 and MYB72 by acting as transcriptional coactivators. It is concluded that IMA peptides regulate processes supporting Fe uptake at both acidic and elevated pH by controlling gene expression upstream of or in concert with a putative pHe signal to adapt the plant to the prevailing edaphic conditions. This regulatory pattern confers tolerance to calcareous soils by extending the pH range in which Fe can be efficiently absorbed from the soil. Altering the expression of IMA peptides provides a novel route for generating plants adapted to calcareous soils.

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