Photosynthetic regulation of C4 desert plant Haloxylon ammodendron under drought stress

About 20-year-old desert plants of C₄ species, Haloxylon ammodendron, growing at the southern edge of the Badain Jaran Desert in China, were selected to study the photosynthetic characteristics and changes in chlorophyll fluorescence when plants were subject to a normal arid environment (AE), moist atmospheric conditions during post-rain (PR), and the artificial supplement of soil water (SW). Results showed that under high radiation, in the AE, the species down-regulated its net assimilation rate (A) and maximum photochemical efficiency of PS II (Fv/Fm), indicating photoinhibition. However, under the PR and SW environments, A was up-regulated, with a unimodal diurnal course of A and a small diurnal change in Fv/Fm, suggesting no photoinhibition. When the air humidity or SW content was increased, the light compensation points were reduced; light saturation points were enhanced; while light saturated rate of CO₂ assimilation (A _max) and apparent quantum yield of CO₂ assimilation (Φ_C) increased. Φ_C was higher while the A _max was reduced under PR relative to the SW treatment. It was concluded that under high-radiation conditions drought stress causes photoinhibition of H. ammodendron. Increasing air humidity or soil moisture content can reduce photoinhibition and increase the efficiency of solar energy use.     

Synthesis of epidermal growth factor (EGF) receptor in vitro using SP6 RNA polymerase-transcribed template mRNA

The epidermal growth factor (EGF) receptor plays a key role in the control cellular proliferation, and its homology to the avian erythroblastosis virus erb B oncogene implicates its involvement in cellular transformation. The establishment of a correlation between the various structural domains of the EGF receptor and their functional counterparts would greatly advance our understanding of these processes. To this end, we have constructed an expression vector containing the SP6 viral promoter and an adjacent cDNA fragment encoding the full-length EGF receptor. Upon addition of SP6 RNA polymerase, this DNA is capable of generating large amounts of EGF receptor mRNA; this RNA can then be translated in vitro into immunoprecipitable EGF receptor protein. The translational efficiency of this EGF receptor RNA was found to be relatively low: approx. 100-fold lower than globin RNA synthesized using SP6 RNA polymerase. Use of these tools should now permit the synthesis and analysis of mutated EGF receptor protein in an effort to clarify the role of this receptor in growth control.     

RAP80 interacts with the SUMO-conjugating enzyme UBC9 and is a novel target for sumoylation

RAP80, a nuclear protein with two functional ubiquitin-interaction motifs (UIMs) at its N-terminus, plays a critical role in the regulation of estrogen receptor alpha and DNA damage response signaling. A yeast two-hybrid screen identified the SUMO-conjugating enzyme UBC9 as a protein interacting with RAP80. The interaction of RAP80 with UBC9 was confirmed by co-immunoprecipitation and GST pull-down analyses. The region between aa 122-204 was critical for the interaction of RAP80 with UBC9. In addition, we demonstrate that RAP80 is a target for SUMO-1 modification in intact cells. Expression of UBC9 enhanced RAP80 mono-sumoylation and also induced multi-sumoylation of RAP80. In addition to SUMO-1, RAP80 was efficiently conjugated to SUMO-3 but was only a weak substrate for SUMO-2 conjugation. These findings suggest that sumoylation plays a role in the regulation of RAP80 functions.     

The impact of inflammatory cells in malignant ascites on small intestinal ICCs' morphology and function

Malignant ascites is one of the common complication at the late stage of abdominal cancers, which may deteriorate the environment of abdominal cavity and lead to potential damage of functional cells. Interstitial cells of Cajal (ICCs) are mesoderm‐derived mesenchymal cells that function normal gastrointestinal motility. The pathological changes of ICCs or the reduced number may lead to the motility disorders of gastrointestinal tract. In this study, through analysis of malignant ascites which were obtained from cancer patients, we found that inflammatory cells, including tumour‐infiltrating lymphocytes, accounted for 17.26 ± 1.31% and tumour‐associated macrophages, occupied 19.06 ± 2.27% of total cells in the ascites, suggesting these inflammatory cells, in addition to tumour cells, may exert important influence on the tumour environment of abdominal cavity. We further demonstrated that the number of mice ICCs were significant decreased, as well as morphological and functional damage when ICCs were in the simulated tumour microenvironment in vitro. Additionally, we illustrated intestinal myoelectrical activity reduced and irregular with morphological changes of ICCs using the mice model of malignant ascites. In conclusion, our data suggested that inflammatory cells in malignant ascites may damage ICCs of the small intestine and lead to intestinal motility disorders.     

ATG5 is required to limit cell death induced by <Emphasis Type="Italic">Pseudomonas syringae</Emphasis> in <Emphasis Type="Italic">Arabidopsis</Emphasis> and may be mediated by the salicylic acid pathway

Autophagy can be regarded as a protection mechanism to restrict programmed cell death (PCD) induced by pathogen infection during plant innate immunity in the early stages. Autophagy related 5 (ATG5) plays an important role in autophagy in Arabidopsis. We investigated the function of ATG5 in Arabidopsis in the hypersensitive response (HR)-PCD elicited by both virulent and avirulent strains of Pseudomonas syringae pv. tomato bacteria DC3000. Results show that ATG5 plays a vital role in limiting HR induced by P. syringae strains and colocalizes with autophagic bodies during the early phase of bacterial infection. In addition, the P. syringae-induced response is mediated by the salicylic acid (SA) signaling pathway. In summary, ATG5 is required for limiting HR-PCD induced in Arabidopsis by P. syringae strains and may be mediated by SA signaling.     

Parental Monitoring,Parent-Adolescent Communication,and Adolescents’ Trust in Their Parents in China

Purpose

Trust is an important aspect of interpersonal relationships, but little is known about adolescents’ interpersonal trust. The aim of the present study was to examine the associations among parental monitoring, parent-adolescent communication, and adolescents’ trust in their parents in China.

Methods

Data in this study were collected as part of the cross-sectional study of children in China. 3349 adolescents (female 48.6%, age range of 12–15 years) were randomly selected from 35 secondary schools in April, 2009 and administered to the Adolescent Interpersonal Trust Scale, the Parental Monitoring Scale, and the Parent-Adolescent Communication Scale.

Results

Adolescents’ trust in their parents was positively related to parental monitoring and parent-adolescent communication. Furthermore, parent-adolescent communication mediated the association between parental monitoring and adolescents’ trust in their parents. The mediation model fit data of both genders and three age groups equally well.

Conclusions

Parental monitoring and parent-adolescent communication play an importance role in fostering adolescents’ trust in their parents.