Antagonistic RALF peptides control an intergeneric hybridization barrier on Brassicaceae stigmas.

Pollen-pistil interactions establish interspecific/intergeneric pre-zygotic hybridization barriers in plants. The rejection of undesired pollen at the stigma is crucial to avoid outcrossing but can be overcome with the support of mentor pollen. The mechanisms underlying this hybridization barrier are largely unknown. Here, in Arabidopsis, we demonstrate that receptor-like kinases FERONIA/CURVY1/ANJEA/HERCULES RECEPTOR KINASE 1 and cell wall proteins LRX3/4/5 interact on papilla cell surfaces with autocrine stigmatic RALF1/22/23/33 peptide ligands (sRALFs) to establish a lock that blocks the penetration of undesired pollen tubes. Compatible pollen-derived RALF10/11/12/13/25/26/30 peptides (pRALFs) act as a key, outcompeting sRALFs and enabling pollen tube penetration. By treating Arabidopsis stigmas with synthetic pRALFs, we unlock the barrier, facilitating pollen tube penetration from distantly related Brassicaceae species and resulting in interspecific/intergeneric hybrid embryo formation. Therefore, we uncover a "lock-and-key" system governing the hybridization breadth of interspecific/intergeneric crosses in Brassicaceae. Manipulating this system holds promise for facilitating broad hybridization in crops.

Cysteine dioxygenase and taurine are essential for embryo implantation by involving in E2-ERα and P4-PR signaling in mouse.

BACKGROUND: Taurine performs multiple physiological functions, and the maintenance of taurine level for most mammals relies on active uptake from diet and endogenous taurine synthesis through its synthesis enzymes, including cysteine dioxygenase (CDO). In addition, uterus tissue and uterus fluid are rich in taurine, and taurine synthesis is regulated by estrogen (E2) and progesterone (P4), the key hormones priming embryo-uterine crosstalk during embryo implantation, but the functional interactions and mechanisms among which are largely unknown. The present study was thus proposed to identify the effects of CDO and taurine on embryo implantation and related mechanisms by using Cdo knockout (KO) and ovariectomy (OVX) mouse models. RESULTS: The uterine CDO expression was assayed from the first day of plugging (d 1) to d 8 and the results showed that CDO expression level increased from d 1 to d 4, followed by a significant decline on d 5 and persisted to d 8, which was highly correlated with serum and uterine taurine levels, and serum P4 concentration. Next, Cdo KO mouse was established by CRISPER/Cas9. It was showed that Cdo deletion sharply decreased the taurine levels both in serum and uterus tissue, causing implantation defects and severe subfertility. However, the implantation defects in Cdo KO mice were partly rescued by the taurine supplementation. In addition, Cdo deletion led to a sharp decrease in the expressions of P4 receptor (PR) and its responsive genes Ihh, Hoxa10 and Hand2. Although the expression of uterine estrogen receptor (ERα) had no significant change, the levels of ERα induced genes (Muc1, Ltf) during the implantation window were upregulated after Cdo deletion. These accompanied by the suppression of stroma cell proliferation. Meanwhile, E2 inhibited CDO expression through ERα and P4 upregulated CDO expression through PR. CONCLUSION: The present study firstly demonstrates that taurine and CDO play prominent roles in uterine receptivity and embryo implantation by involving in E2-ERα and P4-PR signaling. These are crucial for our understanding the mechanism of embryo implantation, and infer that taurine is a potential agent for improving reproductive efficiency of livestock industry and reproductive medicine.

RALF peptide signaling controls the polytubey block in Arabidopsis.

Fertilization of an egg by multiple sperm (polyspermy) leads to lethal genome imbalance and chromosome segregation defects. In Arabidopsis thaliana, the block to polyspermy is facilitated by a mechanism that prevents polytubey (the arrival of multiple pollen tubes to one ovule). We show here that FERONIA, ANJEA, and HERCULES RECEPTOR KINASE 1 receptor-like kinases located at the septum interact with pollen tube-specific RALF6, 7, 16, 36, and 37 peptide ligands to establish this polytubey block. The same combination of RALF (rapid alkalinization factor) peptides and receptor complexes controls pollen tube reception and rupture inside the targeted ovule. Pollen tube rupture releases the polytubey block at the septum, which allows the emergence of secondary pollen tubes upon fertilization failure. Thus, orchestrated steps in the fertilization process in Arabidopsis are coordinated by the same signaling components to guarantee and optimize reproductive success.

Improvement of pasting and gelling behaviors of waxy maize starch by partial gelatinization and freeze-thawing treatment with xanthan gum.

To improve the pasting and gelling behaviors of waxy maize starch, an aqueous dispersion with or without xanthan gum was subjected to partial gelatinization (5 ℃ above the onset melting temperature of starch) and freeze-thawing treatment. After the treatments, starch granules were slightly deformed, with partial loss of birefringence, and tended to aggregate. The relative crystallinity and thermal stability of waxy maize starch crystals decreased by the treatments. These changes indicated that the treatment affected the inner structure and chain arrangement of the granules. The treated waxy maize starches, however, showed a higher overall pasting viscosity with shorter and more cohesive pastes than that of the native starch. The treated starches formed rigid gels with increased stability against freeze-thawing. The addition of small amounts of xanthan gum enhanced the effects of the treatments.

VPS18-regulated vesicle trafficking controls the secretion of pectin and its modifying enzyme during pollen tube growth in Arabidopsis.

In eukaryotes, homotypic fusion and vacuolar protein sorting (HOPS) as well as class C core vacuole/endosome tethering (CORVET) are evolutionarily conserved membrane tethering complexes that play important roles in lysosomal/vacuolar trafficking. Whether HOPS and CORVET control endomembrane trafficking in pollen tubes, the fastest growing plant cells, remains largely elusive. In this study, we demonstrate that the four core components shared by the two complexes, Vacuole protein sorting 11 (VPS11), VPS16, VPS33, and VPS18, are all essential for pollen tube growth in Arabidopsis thaliana and thus for plant reproduction success. We used VPS18 as a representative core component of the complexes to show that the protein is localized to both multivesicular bodies (MVBs) and the tonoplast in a growing pollen tube. Mutant vps18 pollen tubes grew more slowly in vivo, resulting in a significant reduction in male transmission efficiency. Additional studies revealed that membrane fusion from MVBs to vacuoles is severely compromised in vps18 pollen tubes, corroborating the function of VPS18 in late endocytic trafficking. Furthermore, vps18 pollen tubes produce excessive exocytic vesicles at the apical zone and excessive amounts of pectin and pectin methylesterases in the cell wall. In conclusion, this study establishes an additional conserved role of HOPS/CORVET in homotypic membrane fusion during vacuole biogenesis in pollen tubes and reveals a feedback regulation of HOPS/CORVET in the secretion of cell wall modification enzymes of rapidly growing plant cells.

From wastes to functions: A paper mill sludge-based calcium-containing porous biochar adsorbent for phosphorus removal.

With the increased awareness of reusing solid wastes for higher sustainability and the concern of water pollution associated with phosphorus over-emission, there are strong interests in developing solid waste based adsorbents for purifying phosphorus-containing wastewater. As a rich calcium resource, paper mill sludge (i.e., a major solid waste from pulping industry) can be used as phosphorus removal adsorbent after calcination. Thus, in this work, a simple and clean thermally treating route has been proposed for preparing calcium-containing biochar from paper mill sludge. The effect of the physicochemical properties of paper mill sludge and its carbonization condition on phosphorus adsorption has been analyzed. Moreover, the influence of some key adsorption parameters, e.g., biochar dosage, initial pH of solution, co-existing anions, initial phosphorus concentration and contact time has also been investigated. The results showed that the phosphorus adsorption data could be fitted well with pseudo-second-order kinetic and Langmuir isothermal models. The calculated maximum adsorption capacity of the as-prepared optimal calcium-containing biochar could reach to 68.49 mg·g-1 at 25 °C. Combined with the characterization results, it can be reasonably inferred that the adsorption process was chemisorption-dominated. Lastly, the application of this spent adsorbent in agriculture field has also been discussed. In brief, this work provided a feasible strategy for converting paper mill solid waste to an environmental functional material (i.e., calcium-rich biochar) for remediation of eutrophic water.

AtLURE1/PRK6-mediated signaling promotes conspecific micropylar pollen tube guidance.

Reproductive isolation is a prerequisite to form and maintain a new species. Multiple prezygotic and postzygotic reproductive isolation barriers have been reported in plants. In the model plant, Arabidopsis thaliana conspecific pollen tube precedence controlled by AtLURE1/PRK6-mediated signaling has been recently reported as a major prezygotic reproductive isolation barrier. By accelerating emergence of own pollen tubes from the transmitting tract, A. thaliana ovules promote self-fertilization and thus prevent fertilization by a different species. Taking advantage of a septuple atlure1null mutant, we now report on the role of AtLURE1/PRK6-mediated signaling for micropylar pollen tube guidance. Compared with wild-type (WT) ovules, atlure1null ovules displayed remarkably reduced micropylar pollen tube attraction efficiencies in modified semi-in vivo A. thaliana ovule targeting assays. However, when prk6 mutant pollen tubes were applied, atlure1null ovules showed micropylar attraction efficiencies comparable to that of WT ovules. These findings indicate that AtLURE1/PRK6-mediated signaling regulates micropylar pollen tube attraction in addition to promoting emergence of own pollen tubes from the transmitting tract. Moreover, semi-in vivo ovule targeting competition assays with the same amount of pollen grains from both A. thaliana and Arabidopsis lyrata showed that A. thaliana WT and xiuqiu mutant ovules are mainly targeted by own pollen tubes and that atlure1null mutant ovules are also entered to a large extent by A. lyrata pollen tubes. Taken together, we report that AtLURE1/PRK6-mediated signaling promotes conspecific micropylar pollen tube attraction representing an additional prezygotic isolation barrier.

The research on long-term clinical effects and patients' satisfaction of gabapentin combined with oxycontin in treatment of severe cancer pain.

Gabapentin has been used as an adjuvant for treatment of cancer pain. Previous studies showed that opioids combined with gabapentin for management of cancer pain reduced the dosage of opioids.The objective of this study was to explore the clinical effect and patients' satisfaction of oxycontin combined with gabapentin in treatment of severe cancer pain. After titration of morphine, 60 severe cancer patients with visual analog score (VAS) more than 7 were randomly divided into trial group (n = 30) and control group (n = 30). The control group was administered oxycontin and placebo, and the trial group was given oxycontin and gabapentin. VAS score was recorded pre- and post-treatment; while daily dose of oxycontin, daily cost of pain relief and life quality score were observed 1 week, 1 month, 2 months, 3 months, and 6 months post-treatment. We found that daily dose of oxycontin 1 month post was comparable between the 2 groups (P > 0.05). Three months post, compared with control group (58.0 ±â€Š15.2 mg), average daily dose of oxycontin was significant lower in trial group (33.4 ±â€Š11 mg) (P < 0.001). Average daily cost of pain relief in trail group (34.5 ±â€Š10.2 RMB) was less than the control group (52.4 ±â€Š13.7 RMB) (P < 0.001). Life quality score increased in all of the patients in both group post-treatment (P < 0.05); while life quality score in trail group was greater than in control group 3 months (46.8 ±â€Š4.5 vs 43.5 ±â€Š4.6, P = 0.007) and 6 months (46.5 ±â€Š4.8 vs 41.4 ±â€Š4.3, P < 0.001) post-treatment. The incidence of drowsiness and dizziness was comparable between the 2 groups (P > 0.05), while the incidence of nausea and vomiting (P = 0.038), and constipation (P < 0.001) was higher in the control group.We concluded that oxycontin combined with gabapentin used in severe cancer pain management can control pain effectively, decreased the dose of oxycontin and the cost of cancer pain relief, and reduced the incidence of nausea and vomiting, and constipation, increased the life quality.

[Proton magnetic resonance spectroscopy of prefrontal lobe and thalamus in schizophrenics: correlation with clinical characteristics].

OBJECTIVE: To explore the characteristics of different subtypes of schizophrenics on prefrontal lobe and thalamus by proton magnetic resonance spectroscopy ((1)H-MRS) and its relationship. METHODS: From August 2007 to April 2010 at our center, a total of 159 schizophrenics fulfilling the third edition criteria of Chinese Classification of Mental Disorders (CCMD-III) were recruited. And prefrontal lobe and thalamus were evaluated by multi-voxel (1)H-MRS. There were 88 males and 71 females. There were first-episode (n = 54) and not-first-episode (n = 105), negative subtype (n = 125) and positive subtype (n = 34), medicated (n = 96) and non-medicated (n = 63) by different criteria. The levels of N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine compounds (Cr) were measured and the ratios of NAA/Cr and Cho/Cr determined. Positive and negative syndrome scale (PANSS) and Wisconsin card sorting test (WCST) were also assessed. Only 45 normal controls received (1)H-MRS. RESULTS: On left prefrontal lobe and left thalamus, the NAA/Cr ratios in different subtypes of patients were lower than those in normal controls (P < 0.05 or 0.01). The NAA/Cr ratios in patients of non-first-episode (1.48 ± 0.34), negative subtype (1.40 ± 0.35) and medicated (1.47 ± 0.36) on right thalamus were also lower than those in normal controls (1.62 ± 0.37, t = 2.25, 3.56, 2.28, P < 0.05 or P < 0.01). Compared with positive subtype schizophrenics, the NAA/Cr ratios in those of negative subtype on right thalamus were lower (1.40 ± 0.35 vs 1.60 ± 0.37, t = 2.92, P < 0.01). On right thalamus of non-medicated schizophrenics, there was a negative correlation between the duration of illness and the ratio of NAA/Cr (r = -0.38, P < 0.05) and a positive correlation between the duration of illness and the ratio of Cho/Cr (r = 0.43, P < 0.01). On right thalamus of negative subtype schizophrenics, the ratios of NAA/Cr were negatively correlated with the total score of PANSS and the score of negative factor respectively (r = -0.36, -0.40, P < 0.05). On left prefrontal lobe of different subtypes, the ratios of NAA/Cr were negatively correlated with the total score of PANSS, the score of negative factor, responses errors and persistent errors (P < 0.01) and positively correlated with completed categories and conceptual level responses (P < 0.05 or P < 0.01). CONCLUSION: Abnormalities in neuronal function and/or integrity are present on left prefrontal lobe and left thalamus in schizophrenics. And right thalamus is probably involved in non-first-episode subtype, negative subtype and non-medicated subtype. Different subtypes of schizophrenics may have different characteristics of (1)H-MRS due to the duration of illness and their clinical symptoms.