Changes In Endogenous Hormones Research Articles

Effects of low temperature and chilling duration on bud break and changes of endogenous hormones of asparagus

Effects of low temperature and chilling duration on bud break and changes of endogenous hormones of asparagus

Changes in endogenous hormones and seed-coat phenolics during seed storage of two Suaeda salsa populations

Changes in endogenous hormones and seed-coat phenolics during the storage of the dimorphic seeds of two Suaeda salsa populations were investigated. The results showed that, regardless of salinity, storage did not reduce the germination of brown or black seeds from an inland population, but it significantly decreased the germination of dimorphic seeds from an intertidal population. Abscisic acid (ABA) concentration was significantly higher in old seeds than in fresh seeds (freshly harvested dry seeds), whereas the opposite trend was evident for gibberellic acid (GA, including GA1 and GA3) concentration and GA : ABA ratio in both populations, and especially in the intertidal population. Concentration of seed-coat phenolics extracted from brown seeds was much higher than in black seeds in both populations, regardless of extracting time and storage. Storage increased the concentration of phenolics extracted from brown seeds in the inland population, whereas the opposite trend was evident in the intertidal population. Storage did not significantly change seed-coat phenolics extracted from black seeds relative to brown seeds in either population. The results indicated that changes in seed vigour during storage in dimorphic seeds of the two S. salsa populations are related to changes in endogenous hormones and seed-coat phenolics.

Alterations of Endogenous Hormonal Levels in Plants under Drought and Salinity

The phytohormones are pivotal chemical messengers produced within the plant that regulate its growth and development, and responses to environmental stimuli. Drought and salinity are adverse environmental factors that disturb the plant hormonal balance. Accordingly, these hormonal fluctuations modify the cellular dynamic and hence they play a central role in regulating plant growth responses to abiotic stresses such as drought and salinity. The present review gives an update about the alterations of endogenous phytohormones such as abscisic acid (ABA), auxins (Aux), cytokinins (CKs), ethylene (ET), gibberellins (GAs), jasmonates (JAs), salicylic acid (SA), brassinosteroids (BRs), strigolactones (SLs) and nitric oxide (NO) that occur as part of the adaptative responses of plant against drought and salt stresses. Better understanding of the endogenous hormonal changes during the plant response to both abiotic stresses will contribute, in part, to the development of stress-tolerant plants.

Morphological and Physiological Changes in <i>Sedum spectabile </i>during Flower Formation Induced by Photoperiod

Sedum spectabile is an ornamental herbaceous perennial considered as a long-day plant. Varying levels of hormones and sugars possibly affect flower bud formation. This study aimed to determine the changes in endogenous hormones, sugars, and respiration levels in leaves and in apical buds. In addition, the current research was also conducted to observe the morphological changes during the induction, initiation and development of flower buds. Results showed that the periods of floral induction, initiation and development of S. spectabile were the period from 0 d to 1 d, 2 d to 10 d and after 11 d respectively under long day of 20 hours. High zeatin level in apical buds was conducive to floral induction; the increasing levels of gibberrelin and indole acetic acid favor floral initiation; floral development was regulated by mutually synergistic and antagonistic relationships of hormones. The total starch content in leaves remarkably decreased during floral induction. Moreover, soluble sugar content increased and reached the maximum level at 20 d of the treatment period. Afterward, soluble sugar content declined rapidly and was probably transported to the apical buds for rapid floral development. Furthermore, the total respiration of leaves maintained an upward trend; the cytochrome pathway also maintained an increasing trend after the plants were treated for 20 d. Such changes may favour the morphological differentiation of apical buds in floral development.

Morphological and Physiological Changes in Sedum spectabile during Flower Formation Induced by Photoperiod

Sedum spectabile is an ornamental herbaceous perennial considered as a long-day plant. Varying levels of hormones and sugars possibly affect flower bud formation. This study aimed to determine the changes in endogenous hormones, sugars, and respiration levels in leaves and in apical buds. In addition, the current research was also conducted to observe the morphological changes during the induction, initiation and development of flower buds. Results showed that the periods of floral induction, initiation and development of S. spectabile were the period from 0 d to 1 d, 2 d to 10 d and after 11 d respectively under long day of 20 hours. High zeatin level in apical buds was conducive to floral induction; the increasing levels of gibberrelin and indole acetic acid favor floral initiation; floral development was regulated by mutually synergistic and antagonistic relationships of hormones. The total starch content in leaves remarkably decreased during floral induction. Moreover, soluble sugar content increased and reached the maximum level at 20 d of the treatment period. Afterward, soluble sugar content declined rapidly and was probably transported to the apical buds for rapid floral development. Furthermore, the total respiration of leaves maintained an upward trend; the cytochrome pathway also maintained an increasing trend after the plants were treated for 20 d. Such changes may favour the morphological differentiation of apical buds in floral development.

Cadmium stress alters the redox reaction and hormone balance in oilseed rape (Brassica napus L.) leaves.

In order to understand the physiological response of oilseed rape (Brassica napus L.) leaves to cadmium (Cd) stress and exploit the physiological mechanisms involved in Cd tolerance, macro-mineral and chlorophyll concentrations, reactive oxygen species (ROS) accumulation, activities of enzymatic antioxidants, nonenzymatic compounds metabolism, endogenous hormonal changes, and balance in leaves of oilseed rape exposed to 0, 100, or 200 μM CdSO4 were investigated. The results showed that under Cd exposure, Cd concentrations in the leaves continually increased while macro-minerals and chlorophyll concentrations decreased significantly. Meanwhile, with increased Cd stress, superoxide anion (O2(• -)) production rate and hydrogen peroxide (H2O2) concentrations in the leaves increased significantly, which caused malondialdehyde (MDA) accumulation and oxidative stress. For scavenging excess accumulated ROS and alleviating oxidative injury in the leaves, the activity of enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), was increased significantly at certain stress levels. However, with increased Cd stress, the antioxidant enzyme activities all showed a trend towards reduction. The nonenzymatic antioxidative compounds, such as proline and total soluble sugars, accumulated continuously with increased Cd stress to play a long-term role in scavenging ROS. In addition, ABA levels also increased continuously with Cd stress while ZR decreased and the ABA/ZR ratio increased, which might also be providing a protective role against Cd toxicity.

The role of hormones in the pathogenesis of psoriasis vulgaris.

Psoriasis vulgaris is a chronic, common skin disease, which affects the patient’s quality of life to the highest degree. Several exogenous factors and endogenous hormonal changes may act as triggers for psoriasis.The skin possesses a true endocrine system, which is very important in multiple systemic diseases. A number of conditions are associated with psoriasis, and its severity can also be influenced by hormones. Even though the sex hormones and prolactin have a major role in psoriasis pathogenicity, there are a lot of other hormones which can influence the psoriasis clinical manifestations: glucocorticoids, epinephrine, thyroid hormones, and insulin.

Changes of Endogenous Hormone Levels during Ovary Growth and Development after Self-and Cross-pollination of Chestnut (<em>Castanea</em>) Cultivar \'Yanshanzaofeng\'

Chinese chestnut trees spread all over the world produce nut and chestnuts that have considerable economical value. Ovary development is an important step in nut production. Normal ovary development probably requires the coordinated action of plant hormones. Endogenous hormone status of chestnut tree, particularly IAA, IBA, GA3 and ZT, influences chestnut ovary development as well as nut yield. Changes in endogenous hormones during ovary development in chestnut cultivar ‘Yanshanzaofeng’ have not been thoroughly investigated. In this study, cultivar ‘Yanshanzaofeng’ and ‘Dabanhong’ were used as materials. About 50~100 pollinated female inflorescences were picked every five days (5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 days, respectively) to determine the IAA, ABA, GA3 and ZT levels by HPLC. The results showed that there were differences between self-and cross- pollination endogenous hormone change rules during the development of ovary. The IAA and GA3 contents in ovary of self-pollination were significantly higher than cross-pollination during pollination and fertilization period, which suggested that lower IAA and GA3 acts as a positive regulator of fertilization. In the first 40 DAP, ZT level in ovaries of self-and cross-pollination almost have the same change rule, but changed dramatically in the last 10 DAP, which suggested that ZT serves as a positive regulator for young fruit. ABA level in ovary of self-pollination was significantly higher than cross-pollination in the first 30 DAP. It seems that high ABA level was probably related with self-incompatibility in chestnut. The findings of this study could lay the scientific basis for spraying GA3, IAA and ZT during ovary development and may have the potential to improve nut yield.

Comparison of Dynamic Changes of Endogenous Plant Hormones and Hormone-Related Gene Expression between Near Isogenic Lines with Normal Spike and Branched Spike Wheat

Branched spike wheat is a hexaploid wheat with branched rachis on its main rachis, and branched rachises in the shoot apex occur and develop just after the two ridges stage. In this study, dynamic changes of four endogenous plant hormones [indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin riboside (ZR)] and the expression of a hormone-related gene were measured among wheat lines with different genotypes and spike morphologies. It is a basis for further exploring the developmental mechanisms of branched spike and for breeding new wheat lines with more spikelets and grains. A group of near isogenic lines (NILs), including one branched spike line, and three normal spike type lines was sampled at four time points from the end of two ridges stage to the floret differentiation stage. The endogenous hormones in young shoots, young leaves and tillering nodes in these lines were measured and the expressions of TaIAR3, encoding IAA amide hydrolase which involvs in the IAA synthesis was detected. The results showed that the contents of IAA exhibited a significant different pattern in branched spike line from those in normal spike lines, while the contents of GA, ABA and ZR showed similar change patterns. The expressions of TaIAR3 were also significantly different between branched spike line and normal spike lines. Both the IAA content and TaIAR3 expression in branched spike wheat were much higher than those in the normal spike lines. These results suggest that quantitative changes in auxin may correspond to different spike morphology. Higher IAA content and TaIAR3 expression might be benefical for promoting the formation and elongation of branched rachis in branched spike wheat line.

Effect of Low-Temperature Plasma on the Structure of Seeds, Growth and Metabolism of Endogenous Phytohormones in Pea (Pisum sativum L.)

The objective of this study was to determine the influence of low-temperature plasma (LTP) on seed surface modification, water uptake by seeds, seed germination and vigor of seedlings, as well as changes in the content of endogenous hormones in pea, (Pisum sativum L. var. Prophet). The study’s authors used diffuse coplanar surface barrier discharge as the source of LTP in various duration times of treatment (from 60 to 600 s). The SEM analysis showed that LTP induced significant changes on the seeds’ surface, which was related to water permeability into the seeds. LTP increased the germination percentage of pea seeds as well as the growth parameters (root and shoot length, dry weight), and the vigor of seedlings and the effects of LTP also depended on exposure time. The LTP-pretreatment produced changes in endogenous hormones (auxins and cytokinins and their catabolites and conjugates), which correlated with increased growth of the pea seedlings. The results suggested an interaction among the modification of seed structure demonstrated by LTP in the induction of faster germination and hormonal activities related to plant signaling and development during the early growth of pea seedlings.

Effect of bending on the dynamic changes of endogenous hormones in shoot terminals of ‘Fuji’ and ‘Gala’ apple trees

Branch bending has been practiced for decades as an effective means of inducing floral buds in ‘Fuji’ apple in China. Endogenous hormones play an important role in apple flowering. The main purpose of this study is to investigate the hormone concentrations (ABA, ZR, IAA and GA) in spurs, medium and long shoot terminals of ‘Fuji’ and ‘Gala’ apple trees subjected to bending of different angles (70°, 90° or 110°). In both cultivars, the proportion of floral buds and spurs increased, but that of medium and long shoots decreased with increasing bending angles. The ABA and ZR concentrations in shoot terminals increased, but the IAA and GA concentrations decreased as the bending angles increased from 70° to 110°. The ZR concentration increased monotonically in spurs apexes, but in medium and long shoot terminals it increased from a minimum on May 10 to a maximum on June 20 for ‘Fuji’ apple trees or on July 20 for ‘Gala’ apple trees, and then decreased thereafter. It was also observed that the ‘Gala’ apple trees had a higher ABA concentration but a lower IAA concentration in shoot terminals than the ‘Fuji’ apple trees. The ZR concentration in spurs apexes of ‘Gala’ apple trees was higher before July 1, and the GA concentration was higher before June 20, but lower after July 20 than the ‘Fuji’. The (IAA + GA + ZR)/ABA ratio of spurs apexes in ‘Fuji’ apple trees decreased with increasing bending angles during the whole growth season, with a significant difference between those bent at 110° and those bent at 70°. There was no significant difference for the ‘Gala’ apple trees. The (IAA + GA + ZR)/ABA ratio peaked on June 20, and it was higher in ‘Fuji’ than in ‘Gala’ apple trees throughout the study period.

The effect of in vitro mycorrhization on growth characteristics, changes in endogenous hormones and performance of microplants in potato (Solanum tuberosum L.)

Potato (Solanum tuberosum L.) plantlets were inoculated in vitro with an arbuscular mycorrhizal fungus (Glomus intraradices) and their growth response, performance and endogenous hormonal status evaluated. A factorial experiment based on a completely randomized design consisting of two potato cultivars (Agria and Sante) and four culture media was conducted with four replications. The culture media included non-inoculated Murashige and Skoog (MS) medium (control), inoculated MS medium, inoculated half-strength MS medium and inoculated MS medium without vitamins and sugar. To do inoculation, germinated spores of fungus were transferred to the root zone of plantlets. Colonization percentage, total chlorophyll content, internodes and stolon length, shoot diameter, shoot and root fresh and dry weight, leaf area and the level of three endogenous hormones (total auxins, gibberellins and cytokinins) were determined. In addition, mini-tuber production was assayed quantitatively and qualitatively. Results demonstrated that the effect of two factors on all characteristics including mini-tuber production was different significantly. Interaction between cultivar and inoculation systems was significantly associated with endogen auxins as well as all range of mini-tuber production. The inoculated MS medium showed the better results, but it did not have significant difference to halfstrength MS in terms of plantlet performance and growing parameters. Responses of both cultivars to inoculation were very conspicuous in the production of endogen hormones. Higher endogen hormone levels were associated with elevated growth parameters, greater biomass production and better plantlet performance.

The effect of in vitro mycorrhization on growth characteristics, changes in endogenous hormones and performance of microplants in potato (Solanum tuberosum L.)

Potato (Solanum tuberosum L.) plantlets were inoculated in vitro with an arbuscular mycorrhizal fungus (Glomus intraradices) and their growth response, performance and endogenous hormonal status evaluated. A factorial experiment based on a completely randomized design consisting of two potato cultivars (Agria and Sante) and four culture media was conducted with four replications. The culture media included non-inoculated Murashige and Skoog (MS) medium (control), inoculated MS medium, inoculated half-strength MS medium and inoculated MS medium without vitamins and sugar. To do inoculation, germinated spores of fungus were transferred to the root zone of plantlets. Colonization percentage, total chlorophyll content, internodes and stolon length, shoot diameter, shoot and root fresh and dry weight, leaf area and the level of three endogenous hormones (total auxins, gibberellins and cytokinins) were determined. In addition, mini-tuber production was assayed quantitatively and qualitatively. Results demonstrated that the effect of two factors on all characteristics including mini-tuber production was different significantly. Interaction between cultivar and inoculation systems was significantly associated with endogen auxins as well as all range of mini-tuber production. The inoculated MS medium showed the better results, but it did not have significant difference to half-strength MS in terms of plantlet performance and growing parameters. Responses of both cultivars to inoculation were very conspicuous in the production of endogen hormones. Higher endogen hormone levels were associated with elevated growth parameters, greater biomass production and better plantlet performance.

Migraine and estrogen.

The aim is to systematically and critically review the relationship between migraine and estrogen, the predominant female sex hormone, with a focus on studies published in the last 18 months. Recent functional MRI (fMRI) studies of the brain support the existence of anatomical and functional differences between men and women, as well as between participants with migraine and healthy controls. In addition to the naturally occurring changes in endogenous sex hormones over the lifespan (e.g. puberty and menopause), exogenous sex hormones (e.g. hormonal contraception or hormone therapy) also may modulate migraine. Recent data support the historical view of an elevated risk of migraine with significant drops in estrogen levels. In addition, several lines of research support that reducing the magnitude of decline in estrogen concentrations prevents menstrually related migraine (MRM) and migraine aura frequency. Current literature has consistently demonstrated that headache, in particular migraine, is more prevalent in women as compared with men, specifically during reproductive years. Recent studies have found differences in headache characteristics, central nervous system anatomy, as well as functional activation by fMRI between the sexes in migraine patients. Although the cause underlying these differences is likely multifactorial, considerable evidence supports an important role for sex hormones. Recent studies continue to support that MRM is precipitated by drops in estrogen concentrations, and minimizing this decline may prevent these headaches. Limited data also suggest that specific regimens of combined hormone contraceptive use in MRM and migraine with aura may decrease both headache frequency and aura.

Longitudinal Assessment of the Menopausal Transition, Endogenous Sex Hormones, and Perception of Physical Functioning: The Study of Women's Health Across the Nation

To evaluate the longitudinal associations between menopausal status, related hormonal changes, and level of self-reported physical functioning. Study included 2,495 women (age: 45-57 between 2000 and 2001) from the Study of Women's Health Across the Nation. Physical functioning scale of the Medical Outcomes Study Short-Form (SF-36; score 0-100) was categorized as: no limitation (86-100), moderate limitation (51-85), and substantial limitation (0-50). Study variables were collected between 2000 (visit-04) and 2011 (visit-12) at five timepoints. Statistical models were adjusted for age at visit-04, time since visit-04, ethnicity, site, economic status, level and change in body mass index, level and change in physical activity, and presence of comorbid conditions. In final models, natural and surgical postmenopausal women had significantly higher odds of functional limitation, compared with premenopausal women. Less reduction in estradiol and testosterone since visit-04 were significantly associated with lower odds of functional limitation, while greater increase in sex hormone-binding globulin was associated with higher odds of functional limitation. Our findings suggest the menopause-related changes in endogenous sex hormones as a possible mechanism of action to explain the greater limitation in physical functioning reported in women at midlife.

The Relationship between Polyamines and Hormones in the Regulation of Wheat Grain Filling

The grain weight of wheat is strongly influenced by filling. Polyamines (PA) are involved in regulating plant growth. However, the effects of PA on wheat grain filling and its mechanism of action are unclear. The objective of the present study was to investigate the relationship between PAs and hormones in the regulation of wheat grain filling. Three PAs, spermidine (Spd), spermine (Spm), and putrescine (Put), were exogenously applied, and the grain filling characteristics and changes in endogenous PA and hormones, i.e., indole-3-acetic acid (IAA), zeatin (Z) + zeatin riboside (ZR), abscisic acid (ABA), ethylene (ETH) and gibberellin 1+4 (GAs), were quantified during wheat grain filling. Exogenous applications of Spd and Spm significantly increased the grain filling rate and weight, but exogenous Put had no significant effects on these measures. Exogenous Spd and Spm significantly increased the endogenous Spd, Spm, Z+ZR, ABA, and IAA contents and significantly decreased ETH evolution in grains. The endogenous Spd, Spm and Z+ZR contents were positively and significantly correlated with the grain filling rate and weight of wheat, and the endogenous ETH evolution was negatively and significantly correlated with the wheat grain filling rate and weight. Based upon these results, we concluded that PAs were involved in the balance of hormones that regulated the grain filling of wheat.

Seasonal Changes in Endogenous Plant Hormones and Alternate Bearing of Nabali Olive (Olea europea L.)Trees

Seasonal Changes in Endogenous Plant Hormones and Alternate Bearing of Nabali Olive (Olea europea L.)Trees

Waist circumference and menopausal status are independent predictors of endothelial low-grade inflammation.

Background: The high-sensitivity C-reactive protein (hs-CRP) seems to be associated with the presence of atherosclerosis. The association between menopause-related changes in endogenous sex hormones and hs-CRP levels remains controversial. Objective: To compare the levels of hs-CRP in pre- and postmenopausal women and to evaluate the association of endogenous sex hormones, waist circumference (WC) and insulin resistance with the levels of hs-CRP. Methods: This cross-sectional study included 145 women (age range: 45–65 years), 56 premenopausal and 89 postmenopausal. Patients were evaluated for hormonal and lipid profile, HOMA-IR, hs-CRP and WC. Each variable was first assessed for correlation with log hs-CRP using a univariate model, and significant variables were then added to the multivariate regression model. A p value <0.05 was considered statistically significant. Results: The hs-CRP is higher in postmenopausal patients (3.6 ± 4.9 versus 2.6 ± 3.7, p = 0.004). The log hs-CRP was positively correlated with WC (r = 0.13, p = 0.005), HOMA-IR (r = 0.29, p = 0.001), and triglycerides (r = 0.50, p = 0.01). The menopausal status (p = 0.02) and WC (p = 0.00003) behaved as independent predictors of hs-CRP levels. No correlation was found between hs-CRP and the time since menopause (r = −0.1, p = 0.58). Conclusions: The hs-CRP is higher in postmenopausal patients. The menopausal status and WC were independently associated with hs-CRP levels in this sample of pre and postmenopausal women.

Assessing effects of environmental chemicals on neuroendocrine systems: Potential mechanisms and functional outcomes

Environmental pollutants encompass a vast array of compounds. Most studies in birds have focused on toxicological effects, with little attention to non-lethal effects. Consequently, it has proven difficult to assess potential risk associated with exposure to endocrine disrupting chemicals (EDCs). Assessing potential adverse effects due to exposure is further complicated by the great variation that occurs across avian species. These include variations in reproductive strategies, life span, sexual differentiation, and migration. Differences in reproductive strategies, particularly in the developmental patterns and mechanisms for precocial and altricial chicks, predispose birds to wide variations in response to steroids and steroid-like EDCs. We have investigated the effects of EDCs in precocial birds including Japanese quail (Coturnix japonica) and mallard ducks (Anas platyrhynchos) as well as in wild altricial songbirds. Studies in Japanese quail characterized endogenous steroid hormone changes during development and have demonstrated that the developing embryo uses the yolk as a ‘steroid hormone depot’. It appears that actual embryonic exposure is quantitatively lower than indicated by the treatment in egg injections and that the true amount of compound necessary for bioactivity may be quite low relative to the actual dosage delivered. Additionally, embryonic exposure to specific EDCs adversely affected sexual differentiation in quail, especially impacting male sexual behavior as well as neural systems, immune response, and thyroid hormones. Many of these studies considered single compounds; however, wild birds are exposed to complex mixtures and multiple compounds. We tested complex mixtures of polychlorinated biphenyls (PCBs) at concentrations that bracketed those found in eggs in contaminated regions. Results indicated that the predictive value of the toxic equivalency (TEQ), based on comparative activation of the aryl hydrocarbon receptor (AhR) relative to dioxin was not as accurate as expected. We discuss the potential of developing an endocrine disruption index (EDI) to bridge the inconsistencies observed between responses predicted by the TEQ and those observed in vivo following exposure to EDCs. Further, we will discuss how an EDI would complement the adverse outcome pathways analyses to consider the range of effects of endocrine disruptors in birds.

Low‐temperature conditioning induces chilling tolerance in ‘Hayward’ kiwifruit by enhancing antioxidant enzyme activity and regulating en‐dogenous hormones levels

To understand the mechanisms leading to the enhanced chilling tolerance of kiwifruit by low-temperature conditioning (LTC, 12 °C for 3 days), this study investigated the effect of LTC on chilling tolerance and changes in antioxidant enzyme activities and endogenous hormones. LTC significantly alleviated chilling injury in kiwifruit. Fruits treated with LTC maintained lower respiration and ethylene production and higher firmness. Furthermore, this treatment inhibited the accumulation of malondialdehyde, superoxide radicals and hydrogen peroxide and the increase in membrane permeability and increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and peroxidase under chilling stress. The treatment also maintained higher levels of endogenous abscisic acid (ABA), indole-3-acetic acid (IAA) and zeatin riboside (ZR), lower gibberellic acid (GA3) levels and higher ABA/GA3 and ABA/IAA ratios. The results suggested that LTC alleviated chilling injury in kiwifruit by improving antioxidant enzyme activities and maintaining higher levels of endogenous ABA, IAA and ZR, lower GA3 levels and higher ABA/GA3 and ABA/IAA ratios.