Rice XA21 binding protein 3 is a ubiquitin ligase required for full Xa21-mediated disease resistance

XA21 is a receptor-like kinase protein in rice (Oryza sativa) that confers gene-for-gene resistance to specific races of the causal agent of bacterial blight disease, Xanthomonas oryzae pv oryzae. We identified XA21 binding protein 3 (XB3), an E3 ubiquitin ligase, as a substrate for the XA21 Ser and Thr kinase. The interaction between XB3 and the kinase domain of XA21 has been shown in yeast and in vitro, and the physical association between XB3 and XA21 in vivo has also been confirmed by coimmunoprecipitation assays. XB3 contains an ankyrin repeat domain and a RING finger motif that is sufficient for its interaction with the kinase domain of XA21 and for its E3 ubiquitin ligase activity, respectively. Transgenic plants with reduced expression of the Xb3 gene are compromised in resistance to the avirulent race of X. oryzae pv oryzae. Furthermore, reduced levels of Xb3 lead to decreased levels of the XA21 protein. These results indicate that Xb3 is necessary for full accumulation of the XA21 protein and for Xa21-mediated resistance.     

Impaired responsiveness of renal sensory nerves in streptozotocin-treated rats and obese Zucker diabetic fatty rats: role of angiotensin

Increasing afferent renal nerve activity decreases efferent renal nerve activity and increases urinary sodium excretion. Activation of renal pelvic mechanosensory nerves is impaired in streptozotocin (STZ)-treated rats (model of type 1 diabetes). Decreased activation of renal sensory nerves would lead to increased efferent renal nerve activity, sodium retention, and hypertension. We examined whether the reduced activation of renal sensory nerves in STZ rats was due to increased renal angiotensin activity and whether activation of the renal sensory nerves was impaired in obese Zucker diabetic fatty (ZDF) rats (model of type 2 diabetes). In an isolated renal pelvic wall preparation from rats treated with STZ for 2 wk, PGE2 failed to increase the release of substance P, from 5 +/- 1 to 6 +/- 1 pg/min. In pelvises from sham STZ rats, PGE2 increased substance P release from 6 +/- 1 to 13 +/- 2 pg/min. Adding losartan to the incubation bath increased PGE2-mediated release of substance P in STZ rats, from 5 +/- 1 to 10 +/- 2 pg/min, but had no effect in sham STZ rats. In pelvises from obese ZDF rats (22-46 wk old), PGE2 increased substance P release from 12.0 +/- 1.2 to 18.3 +/- 1.2 pg/min, which was less than that from lean ZDF rats (10.3 +/- 1.6 to 22.5 +/- 2.4 pg/min). Losartan had no effect on the PGE2-mediated substance P release in obese or lean ZDF rats. We conclude that the mechanisms involved in the decreased responsiveness of the renal sensory nerves in STZ rats involve activation of the renin angiotensin system in STZ but not in obese ZDF rats.     

The myrosinase gene family in Arabidopsis thaliana: gene organization,expression and evolution

Myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1.) is in Brassicaceae species such as Brassica napus and Sinapis alba encoded by two differentially expressed gene families, MA and MB, consisting of about 4 and 10 genes, respectively. Southern blot analysis showed that Arabidopsis thaliana contains three myrosinase genes. These genes were isolated from a genomic library and two of them, TGG1 and TGG2, were sequenced. They were found to be located in an inverted mode with their 3 ends 4.4 kb apart. Their organization was highly conserved with 12 exons and 11 short introns. Comparison of nucleotide sequences of TGG1 and TGG2 exons revealed an overall 75% similarity. In contrast, the overall nucleotide sequence similarity in introns was only 42%. In intron 1 the unusual 5 splice border GC was used. Phylogenetic analyses using both distance matrix and parsimony programs suggested that the Arabidopsis genes could not be grouped with either MA or MB genes. Consequently, these two gene families arose only after Arabidopsis had diverged from the other Brassicaceae species. In situ hybridization experiments showed that TGG1 and TGG2 expressing cells are present in leaf, sepal, petal, and gynoecium. In developing seeds, a few cells reacting with the TGG1 probe, but not with the TGG2 probe, were found indicating a partly different expression of these genes.     

THE INFLUENCE OF INJECTED TRITIATED THYMIDINE ON THE MITOTIC CIRCADIAN RHYTHM IN THE EPITHELIUM OF THE HAMSTER CHEEK POUCH*

The initial effect of an injection of TdR-5-³H (1 μCi/g body weight; 6 Ci/mmol) in the cheek pouch epithelium of the Syrian hamster is an increase in the mitotic index. The increase is observed 1–5 hr after injection, depending upon the time of day when the injection is given, and is followed by compensatory variations in mitotic index. This deviation from the normal circadian rhythm in the mitotic index appears to depend on the fraction of G₂-cells at the time of injection. The main effect is a shortening of t_g2. No effect is observed after injection of non-radioactive TdR or isotonic saline. The results of the present experiment emphasize that unexpected results may be obtained when using mitotic indices from animals labelled with ³H-TdR, as well as the risks of using the PLM-method in a partially synchronized system.     

Dietary sodium modulates the interaction between efferent and afferent renal nerve activity by altering activation of α2-adrenoceptors on renal sensory nerves

Activation of efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which then reflexively decreases ERSNA via activation of the renorenal reflexes to maintain low ERSNA. The ERSNA-ARNA interaction is mediated by norepinephrine (NE) that increases and decreases ARNA by activation of renal α(1)-and α(2)-adrenoceptors (AR), respectively. The ERSNA-induced increases in ARNA are suppressed during a low-sodium (2,470 ± 770% s) and enhanced during a high-sodium diet (5,670 ± 1,260% s). We examined the role of α(2)-AR in modulating the responsiveness of renal sensory nerves during low- and high-sodium diets. Immunohistochemical analysis suggested the presence of α(2A)-AR and α(2C)-AR subtypes on renal sensory nerves. During the low-sodium diet, renal pelvic administration of the α(2)-AR antagonist rauwolscine or the AT1 receptor antagonist losartan alone failed to alter the ARNA responses to reflex increases in ERSNA. Likewise, renal pelvic release of substance P produced by 250 pM NE (from 8.0 ± 1.3 to 8.5 ± 1.6 pg/min) was not affected by rauwolscine or losartan alone. However, rauwolscine+losartan enhanced the ARNA responses to reflex increases in ERSNA (4,680 ± 1,240%·s), and renal pelvic release of substance P by 250 pM NE, from 8.3 ± 0.6 to 14.2 ± 0.8 pg/min. During a high-sodium diet, rauwolscine had no effect on the ARNA response to reflex increases in ERSNA or renal pelvic release of substance P produced by NE. Losartan was not examined because of low endogenous ANG II levels in renal pelvic tissue during a high-sodium diet. Increased activation of α(2)-AR contributes to the reduced interaction between ERSNA and ARNA during low-sodium intake, whereas no/minimal activation of α(2)-AR contributes to the enhanced ERSNA-ARNA interaction under conditions of high sodium intake.     

Targeting of two effector protein classes to the type III secretion system by a HpaC- and HpaB-dependent protein complex from Xanthomonas campestris pv. vesicatoria

The Gram-negative plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria translocates effector proteins via a specialized type III secretion (TTS) system into the host cell cytosol. The efficient secretion of many effector proteins depends on the global TTS chaperone HpaB. Here, we identified a novel export control protein, HpaC, which significantly contributes to bacterial pathogenicity. Deletion of hpaC leads to a severe reduction in secretion of effector proteins and the putative type III translocon proteins HrpF and XopA. By contrast, secretion of the TTS pilus protein HrpE is not affected. We provide experimental evidence that HpaC differentiates between two classes of effector proteins. Using an in vivo reporter assay, we found that HpaC specifically promotes the translocation of the effector proteins XopJ and XopF1 into the plant cell, whereas AvrBs3 and XopC are efficiently translocated even in the absence of HpaC. Similar findings were obtained for HpaB. Inhibition of protein synthesis suggests that HpaB is involved in the secretion of stored effector proteins. Furthermore, protein-protein interaction studies revealed that HpaB and HpaC form an oligomeric protein complex and that they interact with members of both effector protein classes and the conserved TTS system component HrcV. Taken together, our data indicate that HpaB and HpaC play a central role in recruiting TTS substrates to the secretion apparatus.     

The Ecology of Scale: Assessment of Regional Energy Turnover and Comparison with Global Food (5 pp)

Goal, Scope and Background Obviously, people assume that the regional production and distribution of food requires less energy turnover, compared with global transports of food. Politicians claim the term “regionality”, maintaining that regionality is a medicine against wasting so much energy for the global food distribution. Additionally the energy turnover is causing pollution. But remarkably, there is a lack of empirical data to support this idea. At the same time, nobody really requires regional origin for non-food items, e.g. for bicycles, dishwashers, furniture or cars etc. The public mainstream asks for regional origin merely for food. Hence, the first scientific issue worked out in this paper is how the energy turnover of comparable food items can be measured, regarding the lifecycle of food in total. That means to investigate the partial systems of crop or breed, of food production, of packaging including transport and distribution up to the point of sale. Secondly, it has to be checked, if the assumed coincidence of low energy turnover and regional origin can be verified. The specific energy turnover, calculated in the unit [kWh per kg] or [kWh per l] of food, is investigated by comparing regional with global process chains for different food items. Two examples of food – fruit juices and lamb meat – are researched, by personal investigation worldwide. Firstly, fruit juices of high grade quality from Brazil, from European origin and from local German farmers are compared, in terms of energy. Secondly, a comparison of lamb meat from New Zealand and lamb meat from local German farmers is conducted. Lamb meat has been investigated, because it is shipped around the world as frozen natural food, not concentrated like juices. In addition, the business size of the food producers is researched for both examples. Methods As a part of LCA the energy turnover of each process step from the very beginning up to the point of sale is investigated. These primary results are the basic empirical data, in order to allocate the energy turnover at the food items as functional units. The results of regional, European-continental and of global process chains are compared. In addition, the issue is investigated, whether the specific energy turnover depends upon the business size. Results and Discussion Surprisingly, the data in both cases demonstrate a strong degressive relation of the specific energy turnover and the business size. Here it is not important, if the business is regional or not. Merely the efficiency and logistics of the production and the operations determine the specific energy turnover. These findings seem closely connected with the business size, because small companies are not able to invest in energy recovering and saving technology. The regional juices business is worsened by the huge number of smallsized transports of the crop and the nearly bottle-wise distribution. Regarding lamb meat we once more find the disadvantages of comparably small farms again. In addition, the German farmers need daily shepherds, fences by night, stables and usually additional feed during the wintertime. All these efforts are not necessary in New Zealand, where the climatic conditions and the open countryside with low population allow rather easy and low energy breeding of lamb. Conclusion The coincidence of economic and ecological facts is obvious. As a matter of fact, in economics there is a strong degressive relation between the production costs and the number of produced items. This relation is very well known as “Economy of Scale.” Our findings lead to similar conclusions, in terms of ecology. That means, the production ecology depends on the number of produced items. Additionally, our results demonstrate a minimum business size, so that we can claim an “Ecology of Scale” as well. However, on the other hand, the reported data and the conclusions are valid for the investigated food items – fruit juices and lamb meat – only. Nevertheless, one conclusion is already evident: The most popular claims for regional food production and distribution instead of global process chains are not generally valid. Small farmers basically need much more energy to produce and distribute their products, compared with bigger units. Both food items demonstrate clearly, that the ecological quality is mainly influenced by the operational efficiency and not by the marketing distance itself. Recommendation and Outlook Much more detailed data of all the investigated operational units, processing fruit juices and lamb meat, have been published (Fleissner 2001). As a further example, we investigate wine from different countries as a further example. Different from fruit juices, which can be shipped as a concentrate, and different from lamb meat, which is shipped as frozen food, wine of high grade quality is always bottled close to the place of origin. That means, that not only the food, but also the heavy weight packaging is transported around the world. So, we are very curious about the results, which we expect for 2004.     

Client satisfaction with abortion care in three Russian cities

This paper explores client satisfaction with abortion care, looking at overall satisfaction and satisfaction with hygiene, comfort and courtesy. The analysis aimed to determine whether client satisfaction was related to the characteristics of the client, in order to guide quality improvement efforts. The analysis is a secondary analysis of data collected in a survey of 489 abortion clients who attended a limited number of hospitals in three cities in Russia. The data were analysed using logistic regression. Client characteristics, in general, did not affect overall satisfaction though there were significant differences in overall satisfaction for unmarried versus married women (OR=0.29, CI=0.13, 0.63). Similarly, most characteristics of the abortion visit were not related to client satisfaction, although women who were awake for the procedure were less likely to be satisfied (OR=0.37, CI=0.16, 0.89). Information provided to abortion clients about self-care was the most important predictor of overall satisfaction for abortion clients (OR=3.55, CI=1.64, 7.69). This suggests that improving the information provided to clients, through training providers and other staff, is important in these settings.