Expression of a cotton MADS-box gene is regulated in anther development and in response to phytohormone signaling

MADS-box gene family encodes a large number and variety of transcription regulators in plants. In this study, a cDNA, GhMADS9, encoding a typical MADS protein with 230 amino acids was isolated from cotton flower cDNA library. Subsequently, a 1,623 bp genomic DNA fragment of GhMADS9 gene was isolated in cotton by PCR. Compared with its cDNA sequence, six introns were found in GhMADS9 gene. Fluorescent microscopy indicated that GhMADS9 protein localized in the nucleus. Transactivation activity assay in yeast cells revealed that GhMADS9 protein did not show transcriptional activation. Quantitative RT-PCR analysis showed that GhMADS9 was specially expressed in cotton anthers. Further in situ hybridization analysis demonstrated that strong expression of GhMADS9 gene was detected in developing pollens, but no or weak signals were found in the other anther tissues. Furthermore, GhMADS9 expression was dramatically up-regulated in anthers with abscisic acid (ABA) treatment, whereas its activity was down-regulated when treated by gibberellin (GA3). Collectively, our results suggest that GhMADS9 is a transcription factor and might be involved in cotton anther/pollen development and in response to ABA and GA3 signaling.

Rising challenge of multidrug-resistant tuberculosis in China:a predictive study using Markov modeling

Background:Multidrug-resistant tuberculosis(MDR-TB)is on the rise in China.This study used a dynamic Markov model to predict the longitudinal trends of MDR-TB in China by 2050 and to assess the effects of alternative control measures.Methods:Eight states of tuberculosis transmission were set up in the Markov model using a hypothetical cohort of 100000 people.The prevalence of MDR-TB and bacteriologically confirmed drug-susceptible tuberculosis(DS-TB+)were simulated and MDR-TB was stratified into whether the disease was treated with the recommended regimen or not.Results:Without any intervention changes to current conditions,the prevalence of DS-TB+was projected to decline 67.7%by 2050,decreasing to 20 per 100000 people,whereas that of MDR-TB was expected to triple to 58/100000.Furthermore,86.2%of the MDR-TB cases would be left untreated by the year of 2050.In the case where MDR-TB detection rate reaches 50%or 70%at 5%per year,the decline in prevalence of MDR-TB would be 25.9 and 36.2%respectively.In the case where treatment coverage was improved to 70%or 100%at 5%per year,MDR-TB prevalence in 2050 would decrease by 13.8 and 24.1%,respectively.If both detection rate and treatment coverage reach 70%,the prevalence of MDR-TB by 2050 would be reduced to 28/100000 by a 51.7%reduction.Conclusions:MDR-TB,especially untreated MDR-TB,would rise rapidly under China’s current MDR-TB control strategies.Interventions designed to promote effective detection and treatment of MDR-TB are imperative in the fights against MDR-TB epidemics.