Hormone Production and Reception among Different Isolates of Phytophthora parasitica and P. palmivora

Mycologia ◽  
1981 ◽  
Vol 73 (3) ◽  
pp. 440 ◽  
Author(s):  
W. H. Ko ◽  
R. K. Kunimoto
1993 ◽  
Vol 71 (12) ◽  
pp. 1672-1674 ◽  
Author(s):  
L. L. Chern ◽  
W. H. Ko

A1 and A2 isolates of Phytophthora parasitica were exposed to light at different stages of sexual development to study the mode of action of light on sexual reproduction. Exposure to light during the process of sexual reproduction reduced the number of oospores produced to about 7% of that produced in darkness. Light was inhibitory to production of α hormones but not receptors of these hormones by both A1 and A2 isolates of P. parasitica. However, after being produced, α hormones were stable under light. The number of oospores produced was greatly reduced when A1 and A2 cultures were exposed to light during hormone induction of sexual reproduction but was not affected when the cultures were exposed to light during oospore formation after hormone induction. The results suggest that the effect of light on sexual reproduction in P. parasitica was mainly through inhibition of hormone production and hormone induction of sexual reproduction. Key words: Phytophthora parasitica, light effect, hormonal regulation.


1996 ◽  
Vol 42 (2) ◽  
pp. 172-176 ◽  
Author(s):  
L. L. Chern ◽  
W. H. Ko ◽  
C. S. Tang

The conditions for improved yields of the α hormones of Phytophthora parasitica compared with those of the original technique established by Ko are described. Both hormones al and α2 were adsorbed on the Millipore filter by exposing both sides of the filter directly to freshly inoculated 40% V-8 agar blocks for 4 days. Usage of polycarbonate membrane in the original method to maintain sterility of the filter was replaced by sterilization of the filter with ethanol. Among five organic solvents tested, 95% ethanol was the most effective in extracting both α hormones from the Millipore filter. A 1-min shaking of the hormone-loaded filter with 95% ethanol was sufficient to extract ca. 95% of hormones α1 and α2. Results on the solubility properties suggest that the α hormones of Phytophthora parasitica are lipid-like natural products and that hormone α2 is more polar than hormone α1.Key words: sex hormone, hormone production, sexual reproduction, Phytophthora parasitica.


Author(s):  
K.S. McCarty ◽  
N.R. Wallace ◽  
W. Litaker ◽  
S. Wells ◽  
G. Eisenbarth

The production of adrenocorticotropic hormone by non-pituitary carcinomas has been documented in several tumors, most frequently small cell carcinoma of the lung, islet cell carcinomas of the pancreas, thymomas and carcinoids. Electron microscopy of these tumors reveals typical membrane-limited "neurosecretory" granules. Confirmation of the granules as adrenocorticotropin (ACTH) requires the use of OsO4 as a primary fixative to give the characteristic cored granule appearance in conjunction with immunohistochemical demonstration of the hormone peptide. Because of the rarity of ectopic ACTH production by mammary carcinomas and the absence of appropriate ultrastructural studies in the two examples of such ectopic hormone production in the literature of which we are aware (1,2), we present biochemical and ultrastructural data from a carcinoma of the breast with apparent ACTH production.The patient had her primary tumor in the right breast in 1969. The tumor recurred as visceral and subcutaneous metastases in 1976 and again in 1977.


1974 ◽  
Vol 76 (4) ◽  
pp. 729-740 ◽  
Author(s):  
Peter Kamp ◽  
Per Platz ◽  
Jørn Nerup

ABSTRACT By means of an indirect immunofluorescence technique, sera from 116 patients with Addison's disease, an equal number of age and sex matched controls and 97 patients with other endocrine diseases were examined for the occurrence of antibody to steroid-producing cells in ovary, testis and adrenal cortex. Fluorescent staining was observed in the theca cells of growing follicles, the theca lutein cells, testicular Leydig cells and adrenal cortical cells, i. e. cells which contain enzyme systems used in steroid hormone production. The "steroid-cell" antibody was present in 24 % of the patients with idiopathic Addison's disease, equally frequent in males and females, and in 17 % of the patients with tuberculous Addison's disease, but was rarely found in controls, including patients with other endocrine diseases. Female hypergonadotrophic hypogonadism made an exception, since the "steroid-cell" antibody was found in about half the cases with this condition.


2020 ◽  
Author(s):  
Luke Elissiry ◽  
Jingwen Sun ◽  
Ann M. Hirsch ◽  
Chong Liu

Synthetic fertilizer is responsible for the greatly increased crop yields that have enabled worldwide industrialization. However, the production and use of such fertilizers are environmentally unfriendly and unsustainable; synthetic fertilizers are produced via non-renewable resources and fertilizer runoff causes groundwater contamination and eutrophication. A promising alternative to synthetic fertilizer is bacterial inoculation. In this process, a symbiotic relationship is formed between a crop and bacteria species that can fix nitrogen, solubilize phosphorus, and stimulate plant hormone production. The bacteria carrier developed here aims to maintain bacteria viability while in storage, protect bacteria while encapsulated, and provide a sustained and controllable bacterial release. This novel bacterial delivery method utilizes inorganic nanomaterials, silica microbeads, to encapsulate symbiotic bacteria. These microbeads, which were produced with aqueous, non-toxic precursors, are sprayed directly onto crop seeds and solidify on the seeds as a resilient silica matrix. The bacterial release from the carrier was found by submerging coated seeds in solution to simulate degradation in soil environments, measuring the number of bacteria released by the plate count technique, and comparing the carrier to seeds coated only in bacteria. The carrier’s effectiveness to enhance plant growth was determined through greenhouse plant assays with alfalfa (<i>Medicago sativa</i>) plants and the nitrogen-fixing <i>Sinorhizobium meliloti</i> Rm1021 strain. When compared to bacteria-only inoculation, the silica microbead carrier exhibited significantly (P < 0.05) increased holding capacity of viable bacteria and increased plant growth by a similar amount, demonstrating the capability of inorganic nanomaterials for microbial delivery. The carrier presented in this work has potential applications for commercial agriculture and presents an opportunity to further pursue more sustainable agricultural practices.


2020 ◽  
Author(s):  
Luke Elissiry ◽  
Jingwen Sun ◽  
Ann M. Hirsch ◽  
Chong Liu

Synthetic fertilizer is responsible for the greatly increased crop yields that have enabled worldwide industrialization. However, the production and use of such fertilizers are environmentally unfriendly and unsustainable; synthetic fertilizers are produced via non-renewable resources and fertilizer runoff causes groundwater contamination and eutrophication. A promising alternative to synthetic fertilizer is bacterial inoculation. In this process, a symbiotic relationship is formed between a crop and bacteria species that can fix nitrogen, solubilize phosphorus, and stimulate plant hormone production. The bacteria carrier developed here aims to maintain bacteria viability while in storage, protect bacteria while encapsulated, and provide a sustained and controllable bacterial release. This novel bacterial delivery method utilizes inorganic nanomaterials, silica microbeads, to encapsulate symbiotic bacteria. These microbeads, which were produced with aqueous, non-toxic precursors, are sprayed directly onto crop seeds and solidify on the seeds as a resilient silica matrix. The bacterial release from the carrier was found by submerging coated seeds in solution to simulate degradation in soil environments, measuring the number of bacteria released by the plate count technique, and comparing the carrier to seeds coated only in bacteria. The carrier’s effectiveness to enhance plant growth was determined through greenhouse plant assays with alfalfa (<i>Medicago sativa</i>) plants and the nitrogen-fixing <i>Sinorhizobium meliloti</i> Rm1021 strain. When compared to bacteria-only inoculation, the silica microbead carrier exhibited significantly (P < 0.05) increased holding capacity of viable bacteria and increased plant growth by a similar amount, demonstrating the capability of inorganic nanomaterials for microbial delivery. The carrier presented in this work has potential applications for commercial agriculture and presents an opportunity to further pursue more sustainable agricultural practices.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Junpei Yamashita ◽  
Yuji Nishiike ◽  
Thomas Fleming ◽  
Daichi Kayo ◽  
Kataaki Okubo

AbstractThe preoptic area (POA) is one of the most evolutionarily conserved regions of the vertebrate brain and contains subsets of neuropeptide-expressing neurons. Here we found in the teleost medaka that two neuropeptides belonging to the secretin family, pituitary adenylate cyclase-activating polypeptide (Pacap) and vasoactive intestinal peptide (Vip), exhibit opposite patterns of sexually dimorphic expression in the same population of POA neurons that project to the anterior pituitary: Pacap is male-biased, whereas Vip is female-biased. Estrogen secreted by the ovary in adulthood was found to attenuate Pacap expression and, conversely, stimulate Vip expression in the female POA, thereby establishing and maintaining their opposite sexual dimorphism. Pituitary organ culture experiments demonstrated that both Pacap and Vip can markedly alter the expression of various anterior pituitary hormones. Collectively, these findings show that males and females use alternative preoptic neuropeptides to regulate anterior pituitary hormones as a result of their different estrogen milieu.


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