SOS5 gene-abscisic acid crosstalk and their interaction with antioxidant system in Arabidopsis thaliana under salt stress

SOS5 locus, encodes cell wall adhesion protein under salt stress conditions in plants, and it is required for normal cell expansion as well as for sustaining cell wall integrity and structure. However, it is still unknown how this gene locus-ABA cross-talk and interacts with the antioxidant mechanism under salt stress conditions. For this purpose, the study focused on mutant sos5-1 plant treated with ABA under NaCl stress and observed its growth and development as well as stomatal aperture, lipid peroxidation, proline, hydrogen peroxide (H₂O₂) and ABA contents, and some antioxidant enzyme activities. In addition, the expression levels of ABA related genes have been analysed by RT-PCR after stress application. According to findings, sos5-1 mutant plants treated with ABA under salt stress resulted in eliminated cellular damage compared to those which are solely exposed to salt stress; other observations include closing of stomata, decreased H₂O₂ content, increased amount of proline, and similarity with the wild type due to induced antioxidant enzyme activities. Besides, both ABA biosynthetic and inducible gene expressions of the mutant plant under salt stress were lower compared to the control, and catabolism gene expression was higher. As a result, SOS5 gene in synergy with ABA, scavenge the ROS by stimulating antioxidant system, leads to an increase in stress related gene expressions and thus contributes to salinity tolerance. This study is significant in the way that it shows how SOS5 gene locus, under salt stress conditions, interacts with antioxidant system in sustaining cell wall integrity.

An assessment of phenolic profiles, fatty acid compositions, and biological activities of two Helichrysum species: H. plicatum and H. chionophilum

In the present study, we aimed to search and compare the biological activities of the ethanol (EtOH), methanol (MeOH), and ethylacetate (EtOAc) solvent extracts of the flower, stem, and root parts of two Helichrysum plants (H. chionophilum (Hc) and H. plicatum subsp. plicatum (Hp)). The antioxidant properties were determined by using (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The enzyme inhibitory effects of the extracts were investigated on butyrylcholinesterase (BChE), acetylcholinesterase (AChE), α-glucosidase, and α-amylase. Palmitic acid (C 16:0) was also determined as major fatty acids in the tested oils (31.21%-67.68%). In both plants, it was found that the EtOAc extracts of the flowers had a strong antioxidant and enzyme inhibitory effect. In conclusion, the results obtained in the present study showed that H. chionophilum and H. plicatum can be seen as a promising source for the natural bioactive compounds that can be used in therapeutic applications. PRACTICAL APPLICATIONS: The members of the genus Helichrysum have been widely taken for therapeutic purposes in traditional medicine as well as food. In this context, we investigated the chemical characterization and biological activities of two Helichrysum species extracts (H. chionophilum and H. plicatum subsp. plicatum). Antioxidant capacity, enzyme inhibition and anti-microbial effects were tested for biological activities. Chemical characterization was identified by high performance liquid chromatography (HPLC) (for phenolic) and gas chromatography-flame ioanization detector (GC-FID) (for fatty acids). Based on our findings, the species may be valuable for designing novel food products.

Transcription factors WRKY11 and WRKY17 are involved in abiotic stress responses in Arabidopsis

Plant WRKY transcription factors play a vital role in abiotic stress tolerance and regulation of plant defense responses. This study examined AtWRKY11 and AtWRKY17 expression under ABA, salt, and osmotic stress at different developmental stages in Arabidopsis. We used reverse transcriptase PCR, quantitative real-time PCR, and promoter:GUS lines to analyze expression. Both genes were upregulated in response to abiotic stress. Next, we applied the same stressors to seedlings of T-DNA insertion wrky11 and 17 knock-out mutants (single and double). Under stress, the mutants exhibited slower germination and compromised root growth compared with the wild type. In most cases, double-mutant seedlings were more affected than single mutants. These results suggest that wrky11 and wrky17 are not strictly limited to plant defense responses but are also involved in conferring stress tolerance.

Follicular fluid cerebellin and betatrophin regulate the metabolic functions of growing follicles in polycystic ovary syndrome

Objective

The aim of this study was to assess the changes of follicular fluid (FF) and serum levels of cerebellin precursor protein 1 (cbln1) and betatrophin in patients with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) with a gonadotropin-releasing hormone (GnRH) antagonist protocol.

Methods

Twenty infertile women with PCOS and 20 control women diagnosed as poor responders undergoing ovarian stimulation with a GnRH antagonist were included. Blood samples were obtained during ovum pick-up. Follicular fluid from a dominant follicle was collected from the subjects. Using enzyme-linked immunosorbent assays, FF and serum levels of cbln1 and betatrophin were measured in both groups of participants. Metabolic and hormonal parameters were also determined and correlated with each other.

Results

Both groups of women had similar serum and FF betatrophin levels (55.0±8.9 ng/mL vs. 53.1±10.3 ng/mL, p=0.11). The serum and FF betatrophin levels of poor responders were found to be similar (49.9±5.9 ng/mL vs. 48.9±10.7 ng/mL, p=0.22). Conversely, the FF cbln1 levels of PCOS women were found to be significantly higher than the serum cbln1 levels (589.1±147.6 ng/L vs. 531.7±74.3 ng/L, p<0.02). The FF cbln1 levels of control participants without PCOS were significantly higher than their serum cbln1 levels (599.3±211.5 ng/L vs. 525.3±87.0 ng/L, p=0.01). Positive correlations were detected among body mass index, insulin resistance, serum insulin, total testosterone, and betatrophin levels in the PCOS group.

Conclusion

Follicular fluid betatrophin and cbln1 concentrations may play a pivotal role on follicular growth in PCOS subjects undergoing IVF/ICSI with an antagonist protocol.

Disturbed endometrial NF-κB expression in women with recurrent implantation failure

OBJECTIVE

This study was planned to investigate whether expression levels of endometrial NF-κB1 and NFκB p65 changes in women with recurrent implantation failure (RIF).

PATIENTS AND METHODS

The study group consists of 30 RIF patients having at least three previous failed IVF cycles. The control group comprises of 30 patients having one or no previous failed attempt. Endometrial samples were obtained from all participants during hysteroscopy at the late follicular phase. Samples underwent ELISA analysis and immunohistochemical staining. The semi-quantitative H-Score method was used for analyzing the intensity of endometrial NF-κB p65 expression.

RESULTS

The concentrations of endometrial NF-κB1 were found to be significantly increased when compared to control subjects. Likewise, significantly increased NF-κB p65 immunoreactivity was detected in the cytoplasm of luminal and glandular epithelial cells. The H-Score of NF-κB p65 in RIF women was found to be significantly increased when compared to control group.

CONCLUSIONS

Increased levels of NF-κB1 and NF-κB p65 in the endometrium of RIF women can disturb physiological inflammation which is known to be positive modulator of endometrial receptivity.

Serum and follicular fluid irisin levels in poor and high responder women undergoing IVF/ICSI

OBJECTIVE

We examined the follicular fluid (FF) and serum levels of irisin in high and poor responders undergoing IVF/ICSI to test whether irisin has a role in the metabolic regulation of energy homeostasis in growing follicle.

PATIENTS AND METHODS

Twenty infertile women with PCOS and 20 poor responder participants undergoing controlled ovarian stimulation (COS) with GnRH antagonist protocol for IVF/ICSI treatment were allocated. Blood was obtained at the time of oocyte retrieval. The follicular fluid content of mature follicles was collected from both high and poor responder women. Irisin levels were measured by using EIA.

RESULTS

There was no significant difference between serum and FF-irisin levels in women with PCOS. (11.18 ± 5.14 µg/mL vs. 11.06 ± 4.93 µg/mL, p < 0.96). In contrast, serum levels of irisin in poor responders were significantly higher than in the FF-irisin levels (13.13 ± 4.27 µg/mL vs. 10.09 ± 4.14 µg/mL, p < 0.01). FF-irisin levels of PCOS subjects were positively and significantly correlated with serum levels of irisin (r: 0.81, p < 0.00). Serum irisin was positively associated with serum levels of total testosterone but was negatively associated with HOMA-IR in the overall patient population. FF-irisin levels were also noted to be negatively correlated with HOMA-IR. Although there is no correlation between serum irisin and AMH levels, FF irisin levels were negatively correlated with serum AMH levels in PCOS subjects. Contrary to PCOS group there were no significant correlation between serum and FF-irisin levels in poor responder group (r: 0.21; p < 0.35).

CONCLUSIONS

The present study is the first attempt to explore the role of irisin in oocyte development by measuring FF and serum levels of this molecules in patients with poor and high responders undergoing IVF/ICSI.

Premature Progesterone Elevation Does Not Affect Pregnancy Outcome in High-Responder Patients Undergoing Short-Interval Coasting in IVF Cycles

Background

We aimed to present the relationship between premature progesterone elevation (PPE) and clinical outcomes in high-responder patients who had a coasting period of <4 days in length due to their high risk of developing ovarian hyperstimulation syndrome (OHSS) and who were treated with a long-acting gonadotropin-releasing hormone agonist (GnRH-agonist) protocol in in vitro fertilization-embryo transfer (IVF-ET) cycles.

Material/Methods

This retrospective study was conducted at the University Hospital Assisted Reproductive Technology Center. The outcomes of 101 patients undergoing IVF- intracytoplasmic sperm injection (ICSI) cycles who showed a high response to COH (estradiol >4000 pg/ml and/or >20 follicles each ≥10 mm in diameter and at least 20% ≥15 mm) and who were coasted for <4 days were evaluated. Number of oocytes, 2 pronuclei (PN) embryos, implantation rate, and live birth rate were measured.

Results

The incidence of PPE was 32.6%. Compared with those without PPE, patients with PPE had a higher number of oocytes retrieved. Total mature and fertilized oocytes and the mean number of embryos transferred were not significantly different between groups. Live birth rates (41.9% vs. 38.7%) and implantation rates (26.5% vs. 23%) were also not significantly divergent in the PPE and non-PPE groups, respectively.

Conclusions

P concentrations ≥1.3 ng/ml on the day of human chorionic gonadotropin (hCG) administration, designated in this study as PPE, does not appear to be related to adverse effects in terms of clinical outcomes in high-responder patients undergoing coasting <4 days due to their high risk of developing OHSS treated with a long-acting GnRH-a protocol in IVF-embryo transfer cycles.

The Arabidopsis thaliana FASCICLIN LIKE ARABINOGALACTAN PROTEIN 4 gene acts synergistically with abscisic acid signalling to control root growth

BACKGROUND AND AIMS

The putative FASCICLIN-LIKE ARABINOGALACTAN PROTEIN 4 (At-FLA4) locus of Arabidopsis thaliana has previously been shown to be required for the normal growth of wild-type roots in response to moderately elevated salinity. However, the genetic and physiological pathway that connects At-FLA4 and normal root growth remains to be elucidated.

METHODS

The radial swelling phenotype of At-fla4 was modulated with growth regulators and their inhibitors. The relationship of At-FLA4 to abscisic acid (ABA) signalling was analysed by probing marker gene expression and the observation of the At-fla4 phenotype in combination with ABA signalling mutants.

KEY RESULTS

Application of ABA suppresses the non-redundant role of At-FLA4 in the salt response. At-FLA4 positively regulates the response to low ABA concentration in roots and is required for the normal expression of ABA- and abiotic stress-induced genes. The At-fla4 phenotype is enhanced in the At-abi4 background, while two genetic suppressors of ABA-induced gene expression are required for salt oversensitivity of At-fla4. Salt oversensitivity in At-fla4 is suppressed by the CYP707A inhibitor abscinazole E2B, and salt oversensitivity in At-fla4 roots is phenocopied by chemical inhibition of ABA biosynthesis.

CONCLUSIONS

The predicted lipid-anchored glycoprotein At-FLA4 positively regulates cell wall biosynthesis and root growth by modulating ABA signalling.