BTB and TAZ domain protein BT4 positively regulates the resistance to Botrytis cinerea in Arabidopsis.

BT4 gene was identified to play an important role in Arabidopsis resistance to pst DC3000 in preliminary studies. However, the specific function and molecular mechanism of BT4 gene in regulation of Arabidopsis resistance to Botrytis cinerea had not been described to date. In this study, we found that the expression of BT4 was induced by wounding and B. cinerea inoculation in Arabidopsis. After inoculated with B. cinerea, T-DNA insertion mutants of the BT4 gene, bt4, showed significant susceptibility symptoms, whereas no significant symptoms were found in wild-type (WT), the complemented transgenic plants (CE), and the overexpression transgenic plants (OE). After inoculated with B. cinerea, the expression levels of JAR1 and PDF1.2 genes in bt4 mutant were induced; however, the expression levels of these genes in bt4 mutant were significantly lower than those in the WT, CE, and OE. These results indicated that the BT4 positively regulate the expression of genes in JA/ET signaling pathways. Therefore, the BT4 may be involved in the regulation of JA/ET signaling pathways to affect Arabidopsis resistance to B. cinerea.

Intracranial rat glioma model for tumor resection and local treatment.

BACKGROUND: Although tumor resection is among the most important prognostic factors, high grade gliomas regrow in most cases. Also, resection of glial tumors in eloquent brain regions is not or only partially possible. Despite these severe restraints, however, only a few in-vivo models have been established to investigate tumor recurrence and local treatment. Here we characterize the intracranial BT4Ca rat glioma as a model for these aspects. NEW METHOD: BT4Ca cells were stereotaxically implanted into the frontal cortex of BDIX rats. Rats were than allocated to (1) a control group, which received no further treatment; (2) a catheter group, where a catheter was implanted for repeated microinjection of vehicle every 3rd day as catheter-control; (3) a resection group, where the tumor was microsurgically removed eight days after cell injection. Postoperatively, survival time, weight and general health condition were scored and the tumor size was histologically assessed. RESULTS: Injection of BT4Ca cells induced fast-growing tumors with a mean survival time of 16 days in the control and catheter groups. Resection significantly prolonged survival time whereby the tumor regrew in all rats. Tumor size was similar between all groups. COMPARISON WITH EXISTING METHOD(S): We here present a robust and reliable intracranial rat glioma model, which is suitable to simulate tumor recurrence after surgical resection and local treatment. Importantly, this model does not require advanced imaging or elaborate surgical techniques. CONCLUSIONS: The intracranial BT4Ca glioma model appears to be a feasible tool to investigate tumor recurrence after resection and to test local treatment.

Novel Nucleolipids of Pyrimidine ß-D-Ribonucleosides: Combinatorial Synthesis, Spectroscopic Characterization, and Cytostatic/Cytotoxic Activities.

Four series of nucleolipids with either uridine, 5-methyluridine, 5-fluorouridine, and 6-azauridine as ß-D-ribonucleoside component have been prepared in a combinatorial (not parallel!) manner (see Formulae). All compounds have been characterized by elemental analyses, ESI mass spectrometry as well as by (1) H-, and (13) C-NMR, and UV spectroscopy. A selection of eight nucleolipids with different lipophilizing moieties, based on earlier findings, as well as of 5-fluorouridine as control were first tested on their cytotoxic effect towards PMA-differentiated human THP-1 macrophages. Those compounds which did not exhibit a significant inhibitory effect on the survival of the macrophages were next tested on their cytostatic/cytotoxic effect towards the human astrocytoma/oligodendroglioma GOS-3 cells as well as against the rat malignant neuroectodermal BT4Ca cell line. Additionally, induction of apoptosis of the cell lines was evaluated. It turned out that particularly a combined lipophilization of the nucleosides by an 2',3'-O-ethyl levulinate residue plus a farnesyl moiety at N(3) of the pyrimidine moiety of the corresponding nucleolipids leads to an active compound with the highest probability.