Changes In Hormone Content Research Articles

Analysis of CYP701A1 genes in Gossypium species and functional characterization through gene silencing

Gibberellins (GA) are known to play crucial roles in various aspects of plant growth and development. The cytochrome P450 enzyme family is recognized for its significance in plant metabolic processes. Specifically, CYP701s, a subgroup of CYP71, encode ent-kaurene oxidase in the gibberellin synthesis pathway. In this study, we analyzed genomic data from 30 Gossypium species, including nine allotetraploid genomes (AD1-AD7, with two each for AD1 and AD2), 21 diploid genomes (A-G, K, with two A-genomes and 12 D-genomes), and Gossypioides kirkii genome as an outgroup for evolutionary analysis, totaling 31 genomes. Subsequently, 40 CYP701A1 genes were identified from various genomes and conducted a comprehensive analysis of their structure and evolution. Virus-induced gene silencing (VIGS) technology was utilized to knock out the GhCYP701A1 gene in Gossypium hirsutum ac TM-1. Subsequent analysis revealed changes in hormone content, with decreased gibberellin levels and notable increases in auxin, cytokinin, and jasmonic acid contents. Conversely, salicylic acid content decreased, while the precursor for ethylene synthesis, 1-aminocyclopropane-1-carboxylic acid (ACC), remained relatively stable. Transcriptome analysis of the gene silencing plants identified 15,962 differentially expressed genes, including 8,376 upregulated and 7,586 downregulated genes. Enrichment analysis through KEGG pathway analysis highlighted 'Plant hormone signal transduction' as a prominent pathway with 234 differentially expressed genes. The study provided insights into the function and regulatory network of the gene.

Physiological and transcriptome analysis of changes in endogenous hormone and sugar content during the formation of tender asparagus stems

Asparagus is a nutritionally dense stem vegetable whose growth and development are correlated with its quality and yield. To investigate the dynamic changes and underlying mechanisms during the elongation and growth process of asparagus stems, we documented the growth pattern of asparagus and selected stem segments from four consecutive elongation stages using physiological and transcriptome analyses. Notably, the growth rate of asparagus accelerated at a length of 25 cm. A significant decrease in the concentration of sucrose, fructose, glucose, and additional sugars was observed in the elongation region of tender stems. Conversely, the levels of auxin and gibberellins(GAs) were elevated along with increased activity of enzymes involved in sucrose degradation. A significant positive correlation existed between auxin, GAs, and enzymes involved in sucrose degradation. The ABA content gradually increased with stem elongation. The tissue section showed that cell elongation is an inherent manifestation of stem elongation. The differential genes screened by transcriptome analysis were enriched in pathways such as starch and sucrose metabolism, phytohormone synthesis metabolism, and signal transduction. The expression levels of genes such as ARF, GA20ox, NCED, PIF4, and otherswere upregulated during stem elongation, while DAO, GA2ox, and other genes were downregulated. The gene expression level was consistent with changes in hormone content and influenced the cell length elongation. Additionally, the expression results of RT-qPCR were consistent with RNA-seq. The observed variations in gene expression levels, endogenous hormones and sugar changes during the elongation and growth of asparagus tender stems offer valuable insights for future investigations into the molecular mechanisms of asparagus stem growth and development and provide a theoretical foundation for cultivation and production practices.

Physiological Mechanisms Underlying Tassel Symptom Formation in Maize Infected with Sporisorium reilianum.

Head smut is a soil-borne fungal disease caused by Sporisorium reilianum that infects maize tassels and ears. This disease poses a tremendous threat to global maize production. A previous study found markedly different and stably heritable tassel symptoms in some maize inbred lines with Sipingtou blood after infection with S. reilianum. In the present study, 55 maize inbred lines with Sipingtou blood were inoculated with S. reilianum and classified into three tassel symptom types (A, B, and C). Three maize inbred lines representing these classes (Huangzao4, Jing7, and Chang7-2, respectively) were used as test materials to investigate the physiological mechanisms of tassel formation in infected plants. Changes in enzyme activity, hormone content, and protein expression were analyzed in all three lines after infection and in control plants. The activities of peroxidase (POD), superoxide dismutase (SOD), and phenylalanine-ammonia-lyase (PAL) were increased in the three typical inbred lines after inoculation. POD and SOD activities showed similar trends between lines, with the increase percentage peaking at the V12 stage (POD: 57.06%, 63.19%, and 70.28% increases in Huangzao4, Jing7, and Chang7-2, respectively; SOD: 27.01%, 29.62%, and 47.07% in Huangzao4, Jing7, and Chang7-2, respectively. These were all higher than in the disease-resistant inbred line Mo17 at the same growth stage); this stage was found to be key in tassel symptom formation. Levels of gibberellic acid (GA3), indole-3-acetic acid (IAA), and abscisic acid (ABA) were also altered in the three typical maize inbred lines after inoculation, with changes in GA3 and IAA contents tightly correlated with tassel symptoms after S. reilianum infection. The differentially expressed proteins A5H8G4, P09233, and Q8VXG7 were associated with changes in enzyme activity, whereas P49353, P13689, and P10979 were associated with changes in hormone contents. Fungal infection caused reactive oxygen species (ROS) and nitric oxide (NO) bursts in the three typical inbred lines. This ROS accumulation caused biofilm disruption and altered host signaling pathways, whereas NO signaling triggered strong secondary metabolic responses in the host and altered the activities of defense-related enzymes. These factors together resulted in the formation of varying tassel symptoms. Thus, interactions between S. reilianum and susceptible maize materials were influenced by a variety of signals, enzymes, hormones, and metabolic cycles, encompassing a very complex regulatory network. This study preliminarily identified the physiological mechanisms leading to differences in tassel symptoms, deepening our understanding of S. reilianum-maize interactions.

Dynamics of progesterone, estradiol, cortisol, triiodothyronine and indicators of adaptive immunity concentrations in female dogs during estrus

In different periods of postnatal ontogenesis in dogs, as well as in other animals, there are critical physiological periods, the adequacy of which depends on immunoendocrine homeostasis. The estrus in bitches is a critical period because it lasts longer than in other mammals and has specific endocrine and immune changes in the body. In this study authors demonstrated the dynamics of changes in hormone content and indicators of adaptive cellular immunity in bitches during the estrus. Determination of these indicators does not require expensive laboratory equipment and is available in veterinary practice. Taking into account the fact that estrus in dogs lasts long enough, it is not clear enough what indicators and in what terms should be determined for predicting possible dysfunctions of the reproductive system and, as a result, premature impossibility of reproduction in bitches. The peak concentration of progesterone occurs on the 20th day of estrus, the reaction of the immune system, which is manifested by the maximum decrease in the phagocytic activity of neutrophils, should be noted. An increase in the concentration of estradiol on the 5th day of estrus, in contrast to progesterone, had the opposite effect on phagocytic activity of neutrophils, namely, the ability of neutrophils to phagocytosis increased. Further, we conducted clinical animals’ observations for three months after estrus for the possibility of inflammatory processes in the reproductive system development. According to the obtained indicators, no complications were found.

Analysis of metabolic and transcription levels provides insights into the interactions of plant hormones and crosstalk with MAPKs in the early signaling response of cherry tomato fruit induced by the yeast cell wall

Yeast cell walls (YCW) are promising bio-based elicitors for controlling post-harvest fruit decay. In this study, 1% YCW induction increased the resistance of cherry tomato fruits, reducing disease incidence by 66%. This study aimed to explore the interaction of hormones and crosstalk with MAPKs (mitogen-activated protein kinases) in the early response of resistance regulation in cherry tomato fruits treated with YCW and U0126. We analyzed the temporal changes in hormone content, the expression of critical genes involved in phytohormone biosynthesis, and signal transduction in cherry tomato fruits response to the induction. Results revealed that jasmonic acid (JA) and brassinosteroids (BR) significantly regulated early resistance response in fruit induced by 1% YCW. The salicylic acid (SA) pathway is inhibited by the activation of the JA pathway. JA and SA signaling pathway crosstalk with the MAPK3 pathway. BR plays an essential role in the regulation of fruit resistance. The BR pathway may function independently when JA/SA and MAPK3 pathways are inhibited.

1365-P: Intermittent Fasting Modifies Pancreatic Glucosensor Mechanism In Diabetic Mice

Background: A specific feature in type-2 diabetes is beta-cell dysfunction, associated to reduction in glucose-stimulated insulin secretion. This function is high-regulated by the glucose sensor mechanism, conformed by GLUT2 and glucokinase, and their expresión is decreased in type-2 diabetes. Intermittent fasting is a recent option in diet control, with alternate cycles of fasting and feeding. In this study we evaluated intermittent fasting in diabetic mice, and its long-term effect in pancreatic GLUT2 and glucokinase expression. Methods: C57BL6 mice were fed with high fat diet for eight weeks, and then intermittent fasting cycles among four weeks. Weight, total caloric intake, fasting and glucose tolerance were determinated. Changes in insulin and glucokinase expression were evatualed by immunohistochemistry assays. Glucose-stimulated insulin secretion, and PDX1, insulin, GLUT2 and glucokinase mRNAs were analyzed in isolated islets. Results: Intermittent fasting caused weight loss, reduction in total caloric intake decrease and enhanced glucose tolerance. In diabetic mice, glucose-stimulated insulin secretion was restored after intermittent fasting, without significant changes in hormone content. Treated groups with fasting increased gene expression of PDX1, insulin and GLUT2, but decreased glucokinase mRNA and localization in beta-cells, but enhanced alpha-cell possitive presence. Conclusion: Intermittent fasting modifies glucosensor mechanism in pancreatic islets from diabetic mice, through GLUT2, PDX1 and insulin expression, but glucokinase. On future studies we will determine changes glucokinase enzymatic activity, and another transcription factors involved in these effects. Disclosure A.Vilches-flores: None. Y.Padilla-romero: None. Funding UNAM PAPIIT IN225819

Integrative Transcriptomic and Proteomic Analyses of Molecular Mechanism Responding to Salt Stress during Seed Germination in Hulless Barley.

Hulless barley (Hordeum vulgare L. var. nudum) is one of the most important crops in the Qinghai-Tibet Plateau. Soil salinity seriously affects its cultivation. To investigate the mechanism of salt stress response during seed germination, two contrasting hulless barley genotypes were selected to first investigate the molecular mechanism of seed salinity response during the germination stage using RNA-sequencing and isobaric tags for relative and absolute quantitation technologies. Compared to the salt-sensitive landrace lk621, the salt-tolerant one lk573 germinated normally under salt stress. The changes in hormone contents also differed between lk621 and lk573. In lk573, 1597 differentially expressed genes (DEGs) and 171 differentially expressed proteins (DEPs) were specifically detected at 4 h after salt stress, and correspondingly, 2748 and 328 specifically detected at 16 h. Most specific DEGs in lk573 were involved in response to oxidative stress, biosynthetic process, protein localization, and vesicle-mediated transport, and most specific DEPs were assigned to an oxidation-reduction process, carbohydrate metabolic process, and protein phosphorylation. There were 96 genes specifically differentially expressed at both transcriptomic and proteomic levels in lk573. These results revealed the molecular mechanism of salt tolerance and provided candidate genes for further study and salt-tolerant improvement in hulless barley.

Physiological mechanism and developmental events in differentiating floral buds of Sophora tonkinensis gagnep

Background: Sophora tonkinensis Gagnep is an important medicinal plant in China. Previous research has focused on the rapid propagation and quality analysis of in vitro tissue culture plantlets. Few studies have focused on floral bud differentiation. Physiological and molecular mechanisms regulating floral bud differentiation have not been elucidated. Objective: We used paraffin sections and RNA-seq and then analyzed changes in physiological, biochemical, and endogenous hormones to examine floral bud differentiation. Materials and Methods: Buds were harvested in mid-March or early April. After sorting and cleaning, flower buds physiological and biochemical properties were measured and hormones were determined. Morphological observation of S. tonkinensis was carried out using paraffin sections. Results: The transition from the meristematic to the reproductive phase included changes in the shoot apical meristem morphogenesis and cell differentiation. The process includes floral buds initial differentiation and flower primordium differentiation stages; we defined eight stages in total. There was no significant change in soluble content, but soluble protein content gradually decreased. Activities of antioxidant enzymes changed significantly. Total chlorophyll (Chl a + b) content increased significantly. Endogenous hormone levels changed differently during floral bud differentiation. We identified 104,519 expressed genes and 24 were involved in flowering. MADS-box and AP family genes are involved in flower formation and 40 differentially expressed genes associated with floral bud differentiation were identified. Conclusion: The higher soluble sugar, protein, and chlorophyll content and the higher peroxidase activity were beneficial to floral bud differentiation of S. tonkinensis. The dynamic changes in hormone content contribute to differentiating floral buds.

Physiological Analysis and Transcriptome Profiling of Inverted Cuttings of Populus yunnanensis Reveal That Cell Wall Metabolism Plays a Crucial Role in Responding to Inversion.

Inverted cuttings of Populus yunnanensis remain alive by rooting from the original morphological apex and sprouting from the base, but the lateral branches exhibit less vigorous growth than those of the upright plant. In this study, we examined the changes in hormone contents, oxidase activities, and transcriptome profiles between upright and inverted cuttings of P. yunnanensis. The results showed that the indole-3-acetic acid (IAA) and gibberellic acid (GA3) contents were significantly lower in inverted cuttings than in upright cuttings only in the late growth period (September and October), while the abscisic acid (ABA) level was always similar between the two direction types. The biosynthesis of these hormones was surprisingly unrelated to the inversion of P. yunnanensis during the vegetative growth stage (July and August). Increased levels of peroxidases (PODs) encoded by 13 differentially expressed genes (DEGs) served as lignification promoters that protected plants against oxidative stress. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that most DEGs (107) were related to carbohydrate metabolism. Furthermore, altered activities of uridine diphosphate (UDP)-sugar pyrophosphorylase (USP, 15 DEGs) for nucleotide sugars, pectin methylesterase (PME, 7 DEGs) for pectin, and POD (13 DEGs) for lignin were important factors in the response of the trees to inversion, and these enzymes are all involved cell wall metabolism.

Wounding induces changes in cytokinin and auxin content in potato tuber, but does not induce formation of gibberellins

Cytokinin, auxin and gibberellin contents in resting and wound-responding potato tubers have not been fully determined and coordinated with wound-healing processes. Using a well-defined wound-healing model system, hormone content and expression of genes associated with hormone turnover were determined in tubers following wounding. Changes in hormone content were coordinated with: (I) formation and completion of the wound closing layer (0–5/6 days), and (II) initiation of phellogen and wound periderm formation (∼7 days). Quantifiable amounts of biologically active cytokinins (Z, DZ and IP) were not detected in resting or wound-responding tubers. However, the precursor IPA and catabolic product c-ZOG were found in small amounts in resting and wound-responding tubers. Wound-induced activation of cytokinin biosynthesis was suggested by an increase in t-ZR and c-ZR content at 0.5 days and large increases in IPA and c-ZR content by 3 days and throughout 7 days after wounding suggesting roles in II, but little or no role in I. Expression of key genes involved in cytokinin metabolism followed similar profiles with transcripts decreasing through 3 days and then increasing at 5–7 days after wounding. Both free IAA and IAA-Asp were present in resting tubers. While IAA-Asp was no longer present by 3 days after wounding, IAA content nearly doubled by 5 days and was more than 4-fold greater at 7 days compared to that in resting tuber (0 day) suggesting roles in II, but little or no role in I. Gibberellins were not present in quantifiable amounts in resting or wound-responding tubers. These results suggest that bio-active cytokinins are wound-induced, but their residency is temporal and highly regulated. The transient presence of active cytokinins and corresponding increases in IAA content strongly suggest their involvement in the regulation of wound periderm development. The absence of gibberellins indicates that they are not a regulatory component of wound-healing processes.

Alpha-, Delta- and PP-cells: Are They the Architectural Cornerstones of Islet Structure and Co-ordination?

Islet non-β-cells, the α- δ- and pancreatic polypeptide cells (PP-cells), are important components of islet architecture and intercellular communication. In α-cells, glucagon is found in electron-dense granules; granule exocytosis is calcium-dependent via P/Q-type Ca(2+)-channels, which may be clustered at designated cell membrane sites. Somatostatin-containing δ-cells are neuron-like, creating a network for intra-islet communication. Somatostatin 1-28 and 1-14 have a short bioactive half-life, suggesting inhibitory action via paracrine signaling. PP-cells are the most infrequent islet cell type. The embryologically separate ventral pancreas anlage contains PP-rich islets that are morphologically diffuse and α-cell deficient. Tissue samples taken from the head region are unlikely to be representative of the whole pancreas. PP has anorexic effects on gastro-intestinal function and alters insulin and glucagon secretion. Islet architecture is disrupted in rodent diabetic models, diabetic primates and human Type 1 and Type 2 diabetes, with an increased α-cell population and relocation of non-β-cells to central areas of the islet. In diabetes, the transdifferentiation of non-β-cells, with changes in hormone content, suggests plasticity of islet cells but cellular function may be compromised. Understanding how diabetes-related disordered islet structure influences intra-islet cellular communication could clarify how non-β-cells contribute to the control of islet function.

Adrenocortical System Response to Induction of Inflammation with Silicon Dioxide in Rats with Alloxan-Induced Diabetes Mellitus

Alloxan-induced diabetes mellitus in rats was characterized by persistent increase in blood levels of corticosterone, while chronic granulomatous inflammation induced by silicon dioxide and its combination with alloxan-induced diabetes mellitus were associated with transient increase in blood corticosterone level followed by gradual development of hypoadrenocorticism. The content of corticosterone in the adrenal glands of rats with alloxan-induced diabetes mellitus remained unchanged in the dynamics of the disease, but the level of progesterone decreased at the early terms of diabetes and then returned to the initial values. After administration of silicon dioxide to intact rats and to rats with diabetes mellitus, changes in hormone content in the adrenal glands were observed only at the initial stages of inflammation and consisted in elevation of corticosterone concentration against the background of reduced progesterone content.

Hormone and sugar effects on rice sucrose transporter OsSUT1 expression in germinating embryos

The rice (Oryza sativa L.) OsSUT1 gene encodes a sucrose transporter protein. OsSUT1 was suggested to contribute to phloem loading of sucrose. OsSUT1 expression is highly induced in embryos after seeds were imbibed in water and peaked at 2 days after imbibition, but mRNA levels decline gradually afterwards. In this study, we demonstrated that phytohormones and sugars regulate OsSUT1 expression. Antagonism of abscisic acid and gibberellic acid appeared to play an important role in regulating OsSUT1 expression during embryo germination. In addition, our data showed a glucose and sucrose effect on OsSUT1 expression that represented a bi-phase process. Initially, glucose and sucrose functioned as negative regulators of OsSUT1 expression in germinating embryos after a 1-day treatment; however, when the treatment duration was extended to 5 days, OsSUT1 expression was significantly enhanced. Therefore, we hypothesized that the glucose and sucrose effect might occur in combination with other side effects, such as changes in hormone content or catabolism. Based on the effects that sugar analogs have on OsSUT1 expression, we suggest that the signal transduction for regulating glucose-responsive OsSUT1 expression in embryos occurs via a hexokinase-mediated pathway.

Effect of increased irradiance on the hormone content, water relations, and leaf elongation in wheat seedlings

In wheat (Triticum durum Desf., cv. Bezenchukskaya 139) seedlings, an increase in irradiance from 20 to 400 μmol/(m2 s) PAR enhanced transpiration and increased stomatal conductance by three times on the background of reduced relative water content (RWC). After this treatment, leaves quickly ceased to grow and became even shrunk later. In 40 or 50 min, leaf growth was resumed. At this period, we observed an increase in hydraulic conductivity and RWC and also in leaf extensibility. As soon as 10 min after treatment, some changes in hormone content were noted. In the zones of leaf growth and its mature part, zeatin and zeatin riboside were accumulated, whereas ABA accumulation was observed in the zone of leaf growth and in the roots. The results obtained indicate that leaf expansion at increased irradiance was related to changes in cell-wall extensibility and hydraulic conductivity. The first effect could be due to cytokinin accumulation, whereas the second one, to ABA accumulation.

The short-term growth response to salt of the developing barley leaf

Recent results concerning the short-term growth response to salinity of the developing barley leaf are reviewed. Plants were grown hydroponically and the growth response of leaf 3 was studied between 10 min and 5 d following addition of 100 mM NaCl to the root medium. The aim of the experiments was to relate changes in variables that are likely to affect cell elongation to changes in leaf growth. Changes in hormone content (ABA, cytokinins), water and solute relationships (osmolality, turgor, water potential, solute concentrations), gene expression (water channel), cuticle deposition, membrane potential, and transpiration were followed, while leaf elongation velocity was monitored. Leaf elongation decreased close to zero within seconds following addition of NaCl. Between 20 and 30 min after exposure to salt, elongation velocity recovered rather abruptly, to about 46% of the pre-stress level, and remained at the reduced rate for the following 5 d, when it reached about 70% of the level in non-stressed plants. Biophysical and physiological analyses led to three major conclusions. (i) The immediate reduction and sudden recovery in elongation velocity is due to changes in the water potential gradient between leaf xylem and peripheral elongating cells. Changes in transpiration, ABA and cytokinin content, water channel expression, and plasma membrane potential are involved in this response. (ii) Significant solute accumulation, which aids growth recovery, is detectable from 1 h onwards; growing and non-growing leaf regions and mesophyll and epidermis differ in their solute response. (iii) Cuticular wax density is not affected by short-term exposure to salt; transpirational changes are due to stomatal control.

Testing soil-like substrate for growing plants in bioregenerative life support systems

We studied soil-like substrate (SLS) as a potential candidate for plant cultivation in bioregenerative life support systems (BLSS). The SLS was obtained by successive conversion of wheat straw by oyster mushrooms and worms. Mature SLS contained 9.5% humic acids and 4.9% fulvic acids. First, it was shown that wheat, bean and cucumber yields as well as radish yields when cultivated on mature SLS were comparable to yields obtained on a neutral substrate (expanded clay aggregate) under hydroponics. Second, the possibility of increasing wheat and radish yields on the SLS was assessed at three levels of light intensity: 690, 920 and 1150 μmol m −2 s −1 of photosynthetically active radiation (PAR). The highest wheat yield was obtained at 920 μmol m −2 s −1, while radish yield increased steadily with increasing light intensity. Third, long-term SLS fertility was tested in a BLSS model with mineral and organic matter recycling. Eight cycles of wheat and 13 cycles of radish cultivation were carried out on the SLS in the experimental system. Correlation coefficients between SLS nitrogen content and total wheat biomass and grain yield were 0.92 and 0.97, respectively, and correlation coefficients between nitrogen content and total radish biomass and edible root yield were 0.88 and 0.87, respectively. Changes in hormone content (auxins, gibberellins, cytokinins and abscisic acid) in the SLS during matter recycling did not reduce plant productivity. Quantitative and species compositions of the SLS and irrigation water microflora were also investigated. Microbial community analysis of the SLS showed bacteria from Bacillus, Pseudomonas, Proteus, Nocardia, Mycobacterium, Arthrobacter and Enterobacter genera, and fungi from Trichoderma, Penicillium, Fusarium, Aspergillus, Mucor, Botrytis, and Cladosporium genera.

Changes in hormone content ofPanax quinquefoliumseeds during stratification

SummaryThe changes in hormone contents of Panax quinquefolium seeds during the after-ripening period under controlled stratification conditions were investigated. The seeds were stratified in sequence at 18–20°C for 80 d, at 8–13°C for 54 d and at 0–5°C for 88 d. The water content of the stratified medium (sand) was kept at about 10%. Gibberellin (GA3) and indole-3-acetic acid (IAA) contents in the endosperm were very low at the beginning of stratification, then increased slowly to reach a small peak on day 164 and day 144, respectively, and finally both increased remarkably by day 198. The changes in the GA3 and IAA contents in the embryo were similar to those in the endosperm. Zeatin might be responsible for cell division of the embryo of the seeds. The changing pattern of zeatin content in both the embryo and the endosperm was low-high-low, which corresponded to the changing pattern of the embryo growth rate. Abscisic acid (ABA) concentrations in both the embryo and the endosperm remained high before c...

Recovery of the components of the hypothalamo-pituitary-adrenocortical axis in the rat after chronic treatment with prednisolone.

Male Wistar-derived rats (200-250 g) were treated for 14 days with prednisolone 21-sodium succinate at a concentration of 1035 mumol/l in their drinking water. The drug was then replaced with normal tap water and groups of animals were killed at various times during recovery, trunk blood being collected after decapitation. At the same time, hypothalamic slices, anterior pituitary gland fragments and adrenals were removed and their responsiveness assessed by exposure to appropriate stimuli in vitro. Tissues were also extracted to measure changes in content of hormones during recovery. Treatment with prednisolone produced marked reductions in body weight gain, adrenal weight and pituitary ACTH content, but no significant change in hypothalamic corticotrophin-releasing factor (CRF) bio- or immunoreactivity. The ACTH content was restored by 5 days after withdrawal but adrenal weight remained significantly reduced after 9 days of recovery. The responsiveness of the hypothalamus to acetylcholine in vitro was markedly inhibited and was still significantly reduced 7 days after withdrawal. The responsiveness of the anterior pituitary gland to synthetic CRF or arginine vasopressin and that of the adrenal gland to ACTH added in vitro were restored simultaneously after 7 days of withdrawal. In vivo, recovery was assessed by measurement of the response to laparotomy stress. Treatment with prednisolone prevented the increase in the plasma concentrations of ACTH and corticosterone produced by stress, and these responses recovered by 5 days (corticosterone) and 7 days (ACTH) after withdrawal. The abolition of the circadian rhythms of ACTH and corticosterone by treatment was also reversed by 5 days after withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in Hormone Content of Pear Receptacles from Anthesis to Shortly after Fertilization as Affected by Pollination or GA3 Treatment1

Abstract Concentration of abscisic acid (ABA), abscisic acid-glucose ester (ABA-GE), indoleacetic acid (IAA), zeatin (Z), zeatin riboside (ZR) and gibberellic acid (GA) were measured in ‘Winter Nebs’ pear (Pyrus communis L.) receptacles from anthesis to 12 days thereafter. Concentration of GA or IAA may signal subsequent growth rate for GA3-treated and pollinated receptacles. No correlations with growth were evident for Z or ZR. ABA-GE began massive accumulation prior to the senescence and abscission of control receptacles.

Unilateral ovariectomy-induced luteinizing hormone-releasing hormone content changes in the two halves of the mediobasal hypothalamus

The luteinizing hormone-releasing hormone (LHRH) content of the two halves of the mediobasal hypothalamus (MBH) has been studied two weeks after unilateral or bilateral ovariectomy (OVX) in the rat. In control animals, the LHRH content of the right-side MBH was higher than that of the left side. Right-side OVX induced a significant increase in LHRH content on the right-side MBH while left-side OVX was followed by elevated LHRH content on the left-side MBH. In contrast, bilateral OVX induced a significant decrease on the right-side MBH. The observation that unilateral OVX induced increased LHRH content in the ipsilateral half of the MBH to OVX, supports the view that a neural pathway might connect the ovary and the MBH.