Genetic and transformation studies reveal negative regulation of ERS1 ethylene receptor signaling in Arabidopsis

<p>Abstract</p> <p>Background</p> <p>Ethylene receptor single mutants of Arabidopsis do not display a visibly prominent phenotype, but mutants defective in multiple ethylene receptors exhibit a constitutive ethylene response phenotype. It is inferred that ethylene responses in Arabidopsis are negatively regulated by five functionally redundant ethylene receptors. However, genetic redundancy limits further study of individual receptors and possible receptor interactions. Here, we examined the ethylene response phenotype in two quadruple receptor knockout mutants, (<it>ETR1</it>) <it>ers1 etr2 ein4 ers2 </it>and (<it>ERS1</it>) <it>etr1 etr2 ein4 ers2</it>, to unravel the functions of ETR1 and ERS1. Their functions were also reciprocally inferred from phenotypes of mutants lacking <it>ETR1 </it>or <it>ERS1</it>. Receptor protein levels are correlated with receptor gene expression. Expression levels of the remaining wild-type receptor genes were examined to estimate the receptor amount in each receptor mutant, and to evaluate if effects of <it>ers1 </it>mutations on the ethylene response phenotype were due to receptor functional compensation. As <it>ers1 </it>and <it>ers2 </it>are in the Wassilewskija (Ws) ecotype and <it>etr1</it>, <it>etr2</it>, and <it>ein4 </it>are in the Columbia (Col-0) ecotype, possible effects of ecotype mixture on ethylene responses were also investigated.</p> <p>Results</p> <p>Ethylene responses were scored based on seedling hypocotyl measurement, seedling and rosette growth, and relative <it>Chitinase B </it>(<it>CHIB</it>) expression. Addition of <it>ers1 </it>loss-of-function mutations to any <it>ETR1</it>-containing receptor mutants alleviated ethylene growth inhibition. Growth recovery by <it>ers1 </it>mutation was reversed when the <it>ers1 </it>mutation was complemented by <it>ERS1p:ERS1</it>. The addition of the <it>ers2-3 </it>mutation to receptor mutants did not reverse the growth inhibition. Overexpressing ERS1 receptor protein in (<it>ETR1 ERS1</it>)<it>etr2 ein4 ers2 </it>substantially elevated growth inhibition and <it>CHIB </it>expression. Receptor gene expression analyses did not favor receptor functional compensation upon the loss of <it>ERS1</it>.</p> <p>Conclusions</p> <p>Our results suggest that ERS1 has dual functions in the regulation of ethylene responses. In addition to repressing ethylene responses, ERS1 also promotes ethylene responses in an ETR1-dependent manner. Several lines of evidence support the argument that ecotype mixture does not reverse ethylene responses. Loss of <it>ERS1 </it>did not lead to an increase in total receptor gene expression, and functional compensation was not observed. The inhibitory effects of ERS1 on the ethylene signaling pathway imply negative receptor collaboration.</p

First R and I Lights and Their Photometric Analyses of GSC 02393-00680

We obtained complete $R$ and $I$ light curves of GSC 02393-00680 in 2008 and analyzed them with the 2003 version of the W-D code. It is shown that GSC 02393-00680 is a W-type shallow contact binary system with a high mass ratio $q=1.600$ and a degree of contact factor $f=5.0$. It will be a good example to check up on the TRO theory. A period investigation based on all available data suggests that the system has a small-amplitude period oscillation ($A_3=0.^{d}0030$; $T_3=1.92$years). This may indicate it has a moderate mass close third body, which is similar to XY Leo

Bivariate C1 cubic spline space over a nonuniform type-2 triangulation and its subspaces with boundary conditions

AbstractIn this paper, we discuss the algebraic structure of bivariate C1 cubic spline spaces over nonuniform type-2 triangulation and its subspaces with boundary conditions. The dimensions of these spaces are determined and their local support bases are constructed

The Impact Mechanism of Pro-Environmental Behaviours

Based on the theory of relationship quality, the research constructed the impact mechanism model of pro-environmental behaviours by applying tourist’s perceived value as the antecedent variable, while relationship quality (satisfaction and loyalty) was treated as the mediators, and place attachment as a moderator. Surveys were conducted at the Daweishan National Forest Park in Hunan Province, China, with 674 valid questionnaires collected. The empirical results provided evidence that the direct effect of perceived value of tourists on tourists’ pro-environmental behaviours is significantly positive, and the indirect effect of relationship quality (satisfaction and loyalty) between perceived value of tourists. Recommendations and strategies for further research and implementing tourist stratification management are suggested

Efficacy and safety of Latanoprost/Timolol fixed combinations in treatment of refractory glaucoma following vitrectomy in short period

AIM: To evaluate the efficacy and safety of Latanoprost/Timolol fixed combinations(LTFC)in treatment of refractory glaucoma following vitrectomy in short period.<p>METHODS: In the present study, 42 eyes of 38 refractory glaucoma patients who had received vitrectomy were carried out. The patients were randomly divided into two groups after a 2-week washout period for previous antiglaucoma medication. Patients in group 1 underwent a 6-week treatment with LTFC and those in group 2 were treated with Latanoprost/Timolol unfixed combinations(LTuFC)for 6 weeks. The IOP, visual field, and mRNFL were measured after the washout period as the baseline, and after 6 weeks of therapy. Eye condition and adverse reactions were observed. <p>RESULTS: The mean baseline IOPs of groups 1 and 2 were respectively 37.90±3.74mmHg and 37.57±3.23mmHg. After 6 weeks, the mean IOPs were respectively 30.10±4.90mmHg and 30.62±4.62mmHg, indicating a significant reduction from the baseline(<i>t</i>=12.16, <i>t</i>=13.78, <i>P</i><0.01). No difference was observed in the IOP reduction between LTFC and LTuFC(20.54%±7.88%, 18.23%±7.03%, <i>t</i>=0.75, <i>P</i>>0.05). IOP reduction was 24.87%(20 eyes), 17.46%(15 eyes), and 9.65%(7 eyes)respectively among those with open-angle glaucoma, with partially open-angle glaucoma, and with closed-angle glaucoma. The eye drops didn't have effects on the vision field and mRNFL(all <i>P</i>>0.05), and their main adverse reactions were eye irritation and mild hyperemia.<p>CONCLUSION: In refractory glaucoma, especially in open-angle or partially-open-angle glaucoma, LTFC, administered after vitrectomy, helps to reduce IOP with desirable safetly and tolerance