Rice G-protein subunits qPE9-1 and RGB1 play distinct roles in abscisic acid responses and drought adaptation.

Heterotrimeric GTP-binding protein (G-protein)-mediated abscisic acid (ABA) and drought-stress responses have been documented in numerous plant species. However, our understanding of the function of rice G-protein subunits in ABA signalling and drought tolerance is limited. In this study, the function of G-protein subunits in ABA response and drought resistance in rice plants was explored. It was found that the transcription level of qPE9-1 (rice Gγ subunit) gradually decreased with increasing ABA concentration and the lack of qPE9-1 showed an enhanced drought tolerance in rice plants. In contrast, mRNA levels of RGB1 (rice Gß subunit) were significantly upregulated by ABA treatment and the lack of RGB1 led to reduced drought tolerance. Furthermore, the results suggested that qPE9-1 negatively regulates the ABA response by suppressing the expression of key transcription factors involved in ABA and stress responses, while RGB1 positively regulates ABA biosynthesis by upregulating NCED gene expression under both normal and drought stress conditions. Taken together, it is proposed that RGB1 is a positive regulator of the ABA response and drought adaption in rice plants, whereas qPE9-1 is modulated by RGB1 and functions as a negative regulator in the ABA-dependent drought-stress responses.

Surface display of rice stripe virus NSvc2 and analysis of its membrane fusion activity.

Rice stripe virus (RSV) infects rice and is transmitted in a propagative manner by the small brown planthopper. How RSV enters an insect cell to initiate the infection cycle is poorly understood. Sequence analysis revealed that the RSV NSvc2 protein was similar to the membrane glycoproteins of several members in the family Bunyaviridae and might induce cell membrane fusion. To conveniently study the membrane fusion activity of NSvc2, we constructed cell surface display vectors for expressing Nsvc2 on the insect cell surface as the membrane glycoproteins of the enveloped viruses. Our results showed that NSvc2 was successfully expressed and displayed on the surface of insect Sf9 cells. When induced by low pH, the membrane fusion was not observed in the cells that expressed NSvc2. Additionally, the membrane fusion was also not detected when co-expressing Nsvc2 and the viral capsid protein on insect cell surface. Thus, RSV NSvc2 is probably different from the phlebovirus counterparts, which could suggest different functions. RSV might enter insect cells other than by fusion with plasma or endosome membrane.

Roles of xanthophylls and exogenous ABA in protection against NaCl-induced photodamage in rice (Oryza sativa L) and cabbage (Brassica campestris).

Changes in actual efficiency of PS II photochemistry, non-photochemical quenching (NPQ), content of xanthophylls and kinetics of de-epoxidation were studied in ABA-fed and non-ABA-fed leaves of rice and cabbage under NaCl stress. Salt stress induced more progressive decrease in actual efficiency of PS II photochemistry (ФPS II), higher reduction state of PS II, and a small significant increase in NPQ in NaCl-sensitive rice plants as compared with NaCl-tolerant cabbage plants, whereas exogenously supplied ABA alleviated the decrease in actual efficiency of PS II photochemistry (ФPS II), induced a lower reduction state of PS II, and caused higher capacity of NPQ in ABA-fed plants than in non-ABA-fed plants. As a result, there were higher activities of photosynthetic electron transport, higher capacity of energy dissipation, and lower cumulation of excess light in cabbage than in rice plants, and in ABA-fed leaves than in non-ABA-fed leaves. The effect of ABA was more efficient in cabbage than in rice plants. Addition of exogenous ABA resulted in enhancement of the size of the xanthophyll cycle pool, promotion of de-epoxidation of the xanthophyll cycle components, and a rise in the level of NPQ by altering the kinetics of de-epoxidation of the xanthophyll cycle. Protection from photodamage appears to be achieved by coordinated contributions by exogenous ABA and xanthophyll cycle-mediated NPQ. This variety of photoprotective mechanisms may be essential for conferring photodamage tolerance under NaCl stress.

[Clinical characteristics and therapeutic experience of case of severe highly pathogenic A/H5N1 avian influenza with bronchopleural fistula].

OBJECTIVE: To summarize the clinical characteristics and therapeutic experience of A/H5N1 infected patient with intractable bronchopleural fistula. METHOD: The data of a patient with A/H5N1 infection complicated with bronchopleural fistula was collected and analyzed. RESULTS: A 44-year-old woman with pneuminian was diagnosed as A/H5N1 infection by reverse-transcription polymerase chain reaction (RT-PCR) in laboratory from the sample of secretion of respiratory tracts. She had exposed to sick or dead poultry 3 days before development of illness. She developed acute respiratory distress syndrome 7 days after onset of sickness. After comprehensive management with antiviral agents, antibiotics, convalescent serum and invasive ventilation, her clinical condition improved and turned to stable. However, 16 days after onset of illness, her clinical situation deteriorated due to ventilator-associated pneumonia, bilateral pneumothorax and persistent right bronchopleural fistula. After partly failure of beside assist thoracoscopy to fix the pleural fistula, transbronchoscopic bronchial occlusion by autoblood was explored and the air leakage stopped soon after occlusion. Three days after the autoblood clot was expectorated out and air leak recurred. Then, bronchopleural fistula on the surface of visceral pleura was successfully blocked by biogel and OB gel through pleural cavity by fibrobronchoscopy. The patient was discharged from the hospital 99 days after onset of illness (at the 94th hospital day). CONCLUSION: Bronchopleural fistula was an intractable complication for patient with A/H5N1 infection. Occlusion operation by biogel and OB gel through bronchoscopy might be an alternative choice for fixing the bronchopleural fistula.

[Modified laparoscopic transabdominal preperitoneal repair of groin hernias].

OBJECTIVE: To assess the clinical value of modified transabdominal preperitoneal (TAPP) repair of groin hernias in adult patients. METHOD: From May 2006 to April 2008, modified TAPP repair for hernia was performed in 403 adult patients with groin hernia and 22 with femoral hernia. Indirect hernia sac was treated by high ligation of the hernia sac in similar fashion with the management in children, while direct or femoral hernia was treated by dissecting the hernia sac. An incision was made on the lateral umbilical ligament, and the mesh was stapled and covered completely by the peritoneum of the lateral umbilical ligament, followed by fixation of the mesh with stapling and absorbable sutures. RESULTS: All the operations were accomplished successfully with the operating time from 20 to 30 min for unilateral hemioplasty and the blood loss volume was 4-5 ml. Two patients developed scrotal edema and three showed scrotal seroma. No hernia recurrence was found in follow-up for 2-22 months. The patients complained of no intestinal obstruction symptoms including traction pain, abdominal pain, or nausea or urinary bladder stimulation symptoms. CONCLUSIONS: Modified TAPP repair of groin hernias requires simple operation and produces reliable effect, and is therefore of clinical values for wide application.

Relationships between phosphatidylglycerol molecular species of thylakoid membrane lipids and sensitivities to chilling-induced photoinhibition in rice.

In an attempt to explore the relationships between phosphatidylglycerol (PG) molecular species of thylakoid membrane lipids and sensitivities to chilling-induced photoinhibition, PG molecular species, D1 protein, electron transport activities of thylakoid membrane and the potential quantum yield (F(v)/F(m)) in rice treated under middle and low photon flux density (PFD) at 11 degrees C were analyzed by high performance liquid chromatography, enzyme hydrolysis, gas phase chromatography (GC) and so on. Results showed that the major molecular species of PGs in rice thylakoid membrane were 18:3/16:0, 18:3/16:1(3t), 18:2/16:0, 18:2/16:1(3t), 18:1/16:0, 18:1/16:1(3t), 16:0/16:0, 16:0/16:1(3t). There were large differences in the contents of unsaturated PG molecular species such as 18:1 approximately 3/16:0 approximately 16:1(3t) and saturated PG molecular species like 16:0/16:0 approximately 16:1(3t) among japonica cv 9516 (j-9516), japonica-indica hybrid F1 j-9516/i-SY63 (ji-95SY) and indica cv Shanyou 63 (i-SY63). J-9516 containing higher contents of unsaturated PG molecular species was manifest in stable D1 protein contents under chill and tolerant to chill-induced photoinhibition. In contrast to j-9516, i-SY63 with lower contents of unsaturated PG molecular species, exhibited unstable D1 protein contents under chill and was sensitive to chill-induced photoinhibition. ji-95SY containing middle contents of unsaturated PG molecular species between those of j-9516 and i-SY63, exhibited mid extent of sensitivity to chill-induced photoinhibition. The losses in D1 protein also account for the inhibition in electron transport activity of thylakoid membrane and the observed decline in F(v)/F(m). The PG molecular species that is efficient in raising chilling-resistant capacity were those containing unsaturated fatty acids, namely, unsaturated PG molecular species. These results implied that the substrate selectivity of the glycerol-3-phosphate acyltransferase in chloroplasts towards 16:0 or 18:1 displayed greatly the difference between japonica and indica rice. It was possible to enhance the capacity of resistance to chilling-induced photoinhibition by improving or modifying the GPAT gene.

The co-localization and possible interactions of integrin-like protein and alpha-tubulin in the root cells of Zea mays.

Plant cell wall-plasma membrane-cytoskeleton (CW-PM-CSK) continuum plays important roles in the regulation of plant responses to environmental cues. It has been found in our previous study that an integrin-like protein identified in Arabidopsis and Zea mays plasma membrane mediates the interactions between cell wall and plasma membrane and cell responses to osmotic stress. In the present study, the co-localization of integrin-like protein and alpha-tubulin and their possible interactions were investigated in the root cells of maize using an indirect immunofluorescence technique combined with pharmacological approach. As compared with the control, after treatment with GRGDS, a synthetic peptide contained the RGD domain which binds specifically to integrin-like protein, the integrin-like protein was distributed more evenly over the plasma membrane and the density of alpha-tubulin array became lower. However, treatment with SDGRG, a GRGDS analog which does not contain the RGD domain, had no influences on them. Microtubule-depolymering or -stabilizing reagents exerted their effects either on the distribution over the plasma membrane or on the expression of integrin-like protein. The above results showed that the distribution of integrin-like protein on plasma membrane was closely linked to the alignment of microtubule arrays. Integrin-like protein mediates the interaction between cell wall and plasma membrane, and this interaction in return affected the alignment of microtubule arrays. Changes in cytoskeleton dynamics had significant effect on the distribution of integrin-like protein on the plasma membrane. These results strongly suggest that there are interactions between integrin-like protein and cytoskeleton in plant cells which are very complicated. It is worthy of extensive study to work out the mechanisms of plant responses to intracellular and extracellular signals.

[Microlaparoscopic treatment of adhesive intestinal obstruction in children].

OBJECTIVE: To evaluate the clinical significance of microlaparoscopic treatment for adhesive intestinal obstruction in children. METHODS: Adhesion -lysis operation was performed in 18 patients with adhesive intestinal obstruct ion by microlaparoscope from March 2001 to January 2004. The clinical data were analyzed retrospectively. RESULTS: Microlaparoscope assisted accretion-lysis operation was successfully performed in all patients. The operative time ranged from 15 min to 45 min (averaged 30 min), the aerofluxus time ranged from 12 hours to 28 hours (averaged 22 hours) after operation. All patients can take general activity at the first day and take in food at the second day after operation respectively. The hospital stay ranged from 3 to 5 days (averaged 4 days) without complications. All patients were followed-up from 3 months to 18 months (average d 6 months). All patients recovered well without occurrence of adhesive intestinal obstruction. CONCLUSIONS: Micro-laparoscope assisted adhesion-lysis operation is a simple,safe,and feasible approach for adhesive intestinal obstruction in children.