Expression analysis of Clavata1-like and Nodulin21-like genes from Pinus sylvestris during ectomycorrhiza formation

The ecology and physiology of ectomycorrhizal (EcM) symbiosis with conifer trees are well documented. In comparison, however, very little is known about the molecular regulation of these associations. In an earlier study, we identified three EcM-regulated Pinus expressed sequence tags (EST), two of which were identified as homologous to the Medicago truncatula nodulin MtN21. The third EST was a homologue to the receptor-like kinase Clavata1. We have characterized the expression patterns of these genes and of auxin- and mycorrhiza-regulated genes after induction with indole-3-butyric acid in Pinus sylvestris and in a time course experiment during ectomycorrhizal initiation with the co-inoculation of 2,3,5-triiodobenzoic acid, an auxin transport inhibitor. Our results suggest that different P. sylvestris nodulin homologues are associated with diverse processes in the root. The results also suggest a potential role of the Clv1-like gene in lateral root initiation by the ectomycorrhizal fungus

Matrix Orbit Closures

Let $G$ be the group \GL_r(\CC) \times (\CC^\times)^n. We conjecture that the finely-graded Hilbert series of a $G$ orbit closure in the space of $r$-by-$n$ matrices is wholly determined by the associated matroid. In support of this, we prove that the coefficients of this Hilbert series corresponding to certain hook-shaped Schur functions in the \GL_r(\CC) variables are determined by the matroid, and that the orbit closure has a set-theoretic system of ideal generators whose combinatorics are also so determined. We also discuss relations between these Hilbert series for related matrices

Regulation of differentiation of nitrogen-fixing bacteria by microsymbiont targeting of plant thioredoxin s1

Legumes associate with rhizobia to form nitrogen (N2)-fixing nodules, which is important for plant fitness [1, 2]. Medicago truncatula controls the terminal differentiation of Sinorhizobium meliloti into N2-fixing bacteroids by producing defensin-like nodule-specific cysteine-rich peptides (NCRs) [3, 4]. The redox state of NCRs influences some biological activities in free-living bacteria, but the relevance of redox regulation of NCRs in planta is unknown [5, 6], although redox regulation plays a crucial role in symbiotic nitrogen fixation [7, 8]. Two thioredoxins (Trx), Trx s1 and s2, define a new type of Trx and are expressed principally in nodules [9]. Here, we show that there are four Trx s genes, two of which, Trx s1 and s3, are induced in the nodule infection zone where bacterial differentiation occurs. Trx s1 is targeted to the symbiosomes, the N2-fixing organelles. Trx s1 interacted with NCR247 and NCR335 and increased the cytotoxic effect of NCR335 in S. meliloti. We show that Trx s silencing impairs bacteroid growth and endoreduplication, two features of terminal bacteroid differentiation, and that the ectopic expression of Trx s1 in S. meliloti partially complements the silencing phenotype. Thus, our findings show that Trx s1 is targeted to the bacterial endosymbiont, where it controls NCR activity and bacteroid terminal differentiation. Similarly, Trxs are critical for the activation of defensins produced against infectious microbes in mammalian hosts. Therefore, our results suggest the Trx-mediated regulation of host peptides as a conserved mechanism among symbiotic and pathogenic interactions

Le risque de submersion de tempête en Manche orientale : analyse météo-marine sur la période historique récente.

International audienc

Le risque de submersion de tempête en Manche orientale : analyse météo-marine sur la période historique récente.

International audienc

Oxygen consumption, ammonia excretion and osmoregulation of callinectes similis Juveniles (Crustacea: Portunidae) exposed to fluctuating salinities

The oxygen consumption of Callinectes similis was determined under salinity fluctuations. The metabolic rate remained unchanged (P > 0.05) and within a metabolic range of 1.23 to 2.08 mg O2.h–l.g–l D.W., exhibiting a type IV response according to Kinne (1971). Ammonia excretion rose significantly to 0.028 mg N-NH4.h–l.g–l D.W. (P 0.05) by osmotic stress. In high salinities catabolism is based on carbohydrates and in lower salinities on a mixture of lipids and carbohydrates. The osmoregulatory pattern exhibited by C. similis is of an osmoconforming organism, the hemolymph was only slightly hyperosmotic in higher and isosmotic in lower salinities

Referenciação e articulação de cuidados entre cuidados de saúde primários e cuidados hospitalares de angiologia e cirurgia vascular experiência de um centro

INTRODUCTION: Minimally invasive revascularization of the left anterior descending coronary artery has gained popularity. Recently, the emergence of new surgical instruments and the improvement of the technique, allowed its use by routine. Its use in Heart Team allows excellent results. Our aim is to present the results of patients undergoing this technique in our center. METHODS: Retrospective study of patients submitted to minimally invasive revascularization of the left anterior descending coronary artery at our center. RESULTS: We identified 14 patients. The mean age was 67 years old. In the total of the procedures, 79% were elective and 21% urgent. The ventricular function was preserved in 86% of the patients. In the preoperative catheterization, 64% of the patients showed single disease of the anterior descending coronary artery, 29% had trunk lesions and 3 vessels and 7% had lesion of 2 vessels. The mean Euroscore II was 4.8%. The mean time of surgery was 103 minutes with a mean blood loss of 250mL. The main complications were wound dehiscence and revision of hemostasis. The mean hospitalization rate was 6.2 days. The hospital survival rate was 100%. CONCLUSION: Minimally invasive revascularization allows coronary artery bypass grafting with the best conduit. Revascularization may be total in single disease of the left anterior descending artery, or in case of multivessel disease, achieved with hibrid revascularization, with angioplasty of the remaining vessels. This technique has shown to be promising and safe, being the discussion in Heart Team of the patient candidates essential for achieving the best results.info:eu-repo/semantics/publishedVersio