Abscisic acid (ABA) regulates various aspects of plant physiology, including promoting seed dormancy and adaptive responses to abiotic and biotic stresses. In addition, ABA plays an im-portant role ...in growth and development under non-stressed conditions. This review summarizes phenotypes of ABA biosynthesis and signaling mutants to clarify the roles of basal ABA in growth and development. The promotive and inhibitive actions of ABA in growth are characterized by stunted and enhanced growth of ABA-deficient and insensitive mutants, respectively. Growth regulation by ABA is both promotive and inhibitive, depending on the context, such as concentrations, tissues, and environmental conditions. Basal ABA regulates local growth including hyponastic growth, skotomorphogenesis and lateral root growth. At the cellular level, basal ABA is essential for proper chloroplast biogenesis, central metabolism, and expression of cell-cycle genes. Basal ABA also regulates epidermis development in the shoot, by inhibiting stomatal development, and deposition of hydrophobic polymers like a cuticular wax layer covering the leaf surface. In the root, basal ABA is involved in xylem differentiation and suberization of the endodermis. Hormone crosstalk plays key roles in growth and developmental processes regulated by ABA. Phenotypes of ABA-deficient and insensitive mutants indicate prominent functions of basal ABA in plant growth and development.
Most studies investigating the effects of climatological factors on microbial community composition and diversity focus on comparisons of geographically distinct environments (e.g., cold vs hot ...deserts) or across various temporal scales. Mountain regions provide unique environments to explore relationships between various environmental factors and soil microorganisms given their range of microclimatic conditions and vegetation types. This study investigated micro‐topographically (i.e., north‐/south‐facing slope aspects and flat plateau between them) controlled microbial diversity and community structures across a Lesotho mountain summit. Amplicon sequence analysis revealed that the north‐ and south‐facing slopes were dominated by more Proteobacteria and Bacteroidetes, while the plateau was dominated by more Acidobacteria. Fungi from the phylum Chytridiomycota more strongly dominated the plateau and the north‐facing slope than the south‐facing slope. Slope aspect, through its direct influence on air and soil micro‐climatology and plant diversity, significantly affects bacterial and fungal community structures at this location. These results provide original insight into soil microbial diversity in the Lesotho highlands and offer an opportunity to project the likely response of soil microorganisms to future climate warming in highly variable mountain environments such as the Lesotho highlands.
A peak in the Lesotho highlands sampled in this study showed extensive differences in temperature and relative humidity over a very short spatial scale. Here, by means of amplicon sequence analysis, we show that these factors significantly impact soil microbial ecology. This can serve as a primer to study climate change across short spatial scales.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The human gastrointestinal tract (GIT) is home to an abundance of diverse microorganisms, and the balance of this microbiome plays a vital role in maintaining a healthy GIT. The obstruction of the ...flow of bile into the duodenum, resulting in obstructive jaundice (OJ), has a major impact on the health of the affected individual. This study sought to identify changes in the duodenal microbiota in South African patients with OJ compared to those without this disorder. Mucosal biopsies were taken from the duodenum of nineteen jaundiced patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and nineteen control participants (non-jaundiced patients) undergoing gastroscopy. DNA extracted from the samples was subjected to 16S rRNA amplicon sequencing using the Ion S5 TM sequencing platform. Diversity metrics and statistical correlation analyses with the clinical data were performed to compare duodenal microbial communities in both groups. Differences in the mean distribution of the microbial communities in the jaundiced and non-jaundiced samples were observed; however, this difference did not reach statistical significance. Of note, there was a statistically significant difference between the mean distributions of bacteria comparing jaundiced patients with cholangitis to those without (
= 0.0026). On further subset analysis, a significant difference was observed between patients with benign (Cholelithiasis) and malignant disease, namely, head of pancreas (HOP) mass (
= 0.01). Beta diversity analyses further revealed a significant difference between patients with stone and non-stone related disease when factoring in the Campylobacter-Like Organisms (CLO) test status (
= 0.048). This study demonstrated a shift in the microbiota in jaundiced patients, especially considering some underlying conditions of the upper GI tract. Future studies should aim to verify these findings in a larger cohort.
Inositol phosphates are implicated in the regulation of autophagy; however, the exact role of each inositol phosphate species is unclear. In this study, we systematically analyzed the highly ...conserved inositol polyphosphate synthesis pathway in S. cerevisiae for its role in regulating autophagy. Using yeast mutants that harbored a deletion in each of the genes within the inositol polyphosphate synthesis pathway, we found that deletion of KCS1, and to a lesser degree IPK2, led to a defect in autophagy. KCS1 encodes an inositol hexakisphosphate/heptakisposphate kinase that synthesizes 5-IP
7
and IP
8
; and IPK2 encodes an inositol polyphosphate multikinase required for synthesis of IP
4
and IP
5
. We characterized the kcs1Δ mutant strain in detail. The kcs1Δ yeast exhibited reduced autophagic flux, which might be caused by both the reduction in autophagosome number and autophagosome size as observed under nitrogen starvation. The autophagy defect in kcs1Δ strain was associated with mislocalization of the phagophore assembly site (PAS) and a defect in Atg18 release from the vacuole membrane under nitrogen deprivation conditions. Interestingly, formation of autophagosome-like vesicles was commonly observed to originate from the plasma membrane in the kcs1Δ strain. Our results indicate that lack of KCS1 interferes with proper localization of the PAS, leads to reduction of autophagosome formation, and causes the formation of autophagosome-like structure in abnormal subcellular locations.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Background. Exposure to endotoxin has been widely investigated as a potential factor for asthma and associated symptoms in children with different results. To clarify a potential relationship, we ...performed the present meta-analysis to integrate the results of studies examining the association of endotoxin exposure with wheeze and asthma in children. Methods. A search for relevant studies and reviews was conducted in MEDLINE, Highwire, CINAHL, and The Cochrane Library databases. Adjusted odds ratio (OR) with corresponding 95% confidence interval (CI) for endotoxin exposure and wheeze or asthma were retrieved and pooled to generate summary effect estimates in STATA 11.1. Results. Nineteen studies were included in the meta-analysis. The summary estimates suggested that endotoxin was positively associated with wheeze in infants and toddlers (meta-OR: 1.48, 95% CI: 1.10-1.98), but negatively related to asthma in school-aged children (meta-OR: 0.82, 95% CI: 0.69-0.97 for endotoxin concentration and 0.68, 95% CI: 0.50-0.93 for endotoxin load). Conclusions. Based on the studies evaluated, endotoxin is a risk factor for wheeze in younger children, but a protective factor for asthma in older children. Thus, this study supports the "hygiene hypothesis."
Abstract Background Fast-track surgery has been described as a plan to facilitate early recovery. We present one surgeon's modifications to fast-track surgery for laparoscopic colectomy patients. ...Methods We performed a retrospective review of 48 consecutive patients undergoing elective laparoscopic colectomy treated by a modified fast-track plan between 2004 and 2008. Elements included preoperative education, pre-anesthesia dexamethasone, immediate postoperative general diet, no urinary catheter, no epidural anesthesia, and no flatus or bowel movement as a discharge requirement. Data collected included the following: age, sex, body mass index, resection indications, surgical time, blood loss, pain score, time to ambulation, time to bowel function, length of stay, complications, and mortality. Results The mean length of stay was 37 hours (1.5 d), with 29 of 48 patients discharged without passage of flatus or stool. Only 1 patient required readmission. Conclusions Our modified fast-track plan achieved significant improvement in length of stay for laparoscopic colectomy compared with previous results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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