The NAC-like gene ANTHER INDEHISCENCE FACTOR acts as a repressor that controls anther dehiscence by regulating genes in the jasmonate biosynthesis pathway in Arabidopsis

ANTHER INDEHISCENCE FACTOR (AIF), a NAC-like gene, was identified in Arabidopsis. In AIF:GUS flowers, β-glucuronidase (GUS) activity was detected in the anther, the upper parts of the filaments, and in the pollen of stage 7-9 young flower buds; GUS activity was reduced in mature flowers. Yellow fluorescent protein (YFP)+AIF-C fusion proteins, which lacked a transmembrane domain, accumulated in the nuclei of the Arabidopsis cells, whereas the YFP+AIF fusion proteins accumulated in the membrane and were absent in the nuclei. Further detection of a cleaved AIF protein in flowers revealed that AIF needs to be processed and released from the endoplasmic reticulum in order to function. The ectopic expression of AIF-C caused a male-sterile phenotype with indehiscent anthers throughout flower development in Arabidopsis. The presence of a repressor domain in AIF and the similar phenotype of indehiscent anthers in AIF-C+SRDX plants suggest that AIF acts as a repressor. The defect in anther dehiscence was due to the down-regulation of genes that participate in jasmonic acid (JA) biosynthesis, such as DAD1/AOS/AOC3/OPR3/OPCL1. The external application of JA rescued the anther indehiscence in AIF-C and AIF-C+SRDX flowers. In AIF-C+VP16 plants, which are transgenic dominant-negative mutants in which AIF is converted to a potent activator via fusion to a VP16-AD motif, the anther dehiscence was promoted, and the expression of DAD1/AOS/AOC3/OPR3/OPCL1 was up-regulated. Furthermore, the suppression of AIF through an antisense strategy resulted in a mutant phenotype similar to that observed in the AIF-C+VP16 flowers. The present data suggest a role for AIF in controlling anther dehiscence by suppressing the expression of JA biosynthesis genes in Arabidopsis.

A RING-type E3 ligase controls anther dehiscence by activating the jasmonate biosynthetic pathway gene DEFECTIVE IN ANTHER DEHISCENCE1 in Arabidopsis

Suppression of expression of DAF [DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1)-Activating Factor], a gene that encodes a putative RING-finger E3 ligase protein, causes non-dehiscence of the anthers, alters pollen development and causes sterility in 35S:DAF RNAi/antisense Arabidopsis plants. This mutant phenotype correlates with the suppression of DAF but not with expression of the two most closely related genes, DAFL1/2. The expression of DAD1 was significantly reduced in 35S:DAF RNAi/antisense plants, and complementation with 35S:DAF did not rescue the dad1 mutant, indicating that DAF acts upstream of DAD1 in jasmonic acid biosynthesis. This assumption is supported by the finding that 35S:DAF RNAi/antisense plants showed a similar cellular basis for anther dehiscence to that found in dad1 mutants, and that external application of jasmonic acid rescued the anther non-dehiscence and pollen defects in 35S:DAF antisense flowers. We further demonstrate that DAF is an E3 ubiquitin ligase and that its activity is abolished by C132S and H137Y mutations in its RING motif. Furthermore, ectopic expression of the dominant-negative C132S or H137Y mutations causes similar indehiscence of anthers and reduction in DAD1 expression in transgenic Arabidopsis. This result not only confirms that DAF controls anther dehiscence by positively regulating the expression of DAD1 in the jasmonic acid biosynthesis pathway, but also supports the notion that DAF functions as an E3 ubiquitin ligase, and that the conserved RING-finger region is required for its activity.

Antimicrobial activity and cytotoxicity of the essential oil of Curcuma zedoaria

The chemical compositions of the essential oil of Curcuma zedoaria (Berg.) Rosc. were analyzed by gas chromatography-mass spectrometry (GC-MS) and showed a high content of epicurzerenone and curdione representing 46.6% and 13.7% of the total oil, respectively. The essential oil was evaluated for potential antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonasa aeruginosa, Vibrio parahaemolyticus, Salmonella typhimurium and Bacillus cereus. V. parahaemolyticus was sensitive to the presence of the essential oil, while the most resistant strain appeared to be E. coli. Based on 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay, nitroblue tetrazolium (NBT) reduction and cell morphology, the essential oil of C. zedoaria could inhibit the proliferation of human promyelocytic leukemia HL-60 cells. These results suggest that the essential oil has the antimicrobial activity against some of Gram- positive and negative pathogenic microorganisms and the components of the extract lead to the apoptosis of human cancer cell line.

Statistical methodology for screening studies with qualitative/quantitative mixtures

A statistical method for designing screening studies involving several experimental treatments compared to a standard treatment is developed. The screening study identifies the most promising experimental treatments, which then undergo more rigorous evaluation in a future, larger study. The technique is especially relevant for biopharmaceutical research and development in which phase II clinical trials are conducted to identify the most promising drug regimens, which then move on to phase III of clinical development. It is assumed that the underlying distribution of the primary efficacy random variable is a qualitative/quantitative mixture. The proposed methodology involves calculating the probability of accepting each experimental treatment compared to the standard treatment, where the criterion for acceptance is based on the proportion of qualitative observations and a measure of their location. The probability of acceptance is displayed in two dimensions using operating characteristic contour plots. The techniques are illustrated with some practical examples and some extensions are indicated.

Spurious polycythemia

Spurious polycythemia is not a primary disease process. It sometimes may be nothing more than an unusual, but normal, physiologic state. In other instances, however, it is associated with a true abnormality of plasma volume. Although there is probably overlap between these extremes, differentiation of these subclasses may be of prognostic significance. The elevation in hematocrit bears no relation to morbidity, and, because there is no evidence of abnormal erythroid proliferation, reduction of red cell volume via phlebotomy or myelosuppression is inappropriate. Nonhematologic parameters, particularly hypertension, are the major factors of significance in the substantial cardiovascular morbidity in spurious polycythemia, and they demand attentive and aggressive management.