Agrobacterium rhizogenes—mediated transformation of Pisum sativum L. roots as a tool for studying the mycorrhizal and root nodule symbioses

In this study, we demonstrated the successful transformation of two pea (Pisum sativum L.) cultivars using Agrobacterium rhizogenes, whereby transgenic roots in the resulting composite plants showed expression of the gene encoding the green fluorescent protein. Subsequent to infection with A. rhizogenes, approximately 70%–80% of pea seedlings developed transgenic hairy roots. We found out that the transgenic roots can be efficiently nodulated by Rhizobium leguminosarum bv. viciae and infected by the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis. The morphology of nodules in the transgenic roots was found to be identical to that of nodules observed in wild-type roots, and we also observed the effective induction of markers typical of the symbiotic association with AM fungi. The convenient protocol for highly efficient A. rhizogenes-mediated transformation developed in this study would be a rapid and effective tool for investigating those genes involved in the development of the two types of symbioses found in pea plants

The DELLA Proteins Influence the Expression of Cytokinin Biosynthesis and Response Genes During Nodulation

The key event that initiates nodule organogenesis is the perception of bacterial signal molecules, the Nod factors, triggering a complex of responses in epidermal and cortical cells of the root. The Nod factor signaling pathway interacts with plant hormones, including cytokinins and gibberellins. Activation of cytokinin signaling through the homeodomain-containing transcription factors KNOX is essential for nodule formation. The main regulators of gibberellin signaling, the DELLA proteins are also involved in regulation of nodule formation. However, the interaction between the cytokinin and gibberellin signaling pathways is not fully understood. Here, we show in Pisum sativum L. that the DELLA proteins can activate the expression of KNOX and BELL transcription factors involved in regulation of cytokinin metabolic and response genes. Consistently, pea la cry-s (della1 della2) mutant showed reduced ability to upregulate expression of some cytokinin metabolic genes during nodulation. Our results suggest that DELLA proteins may regulate cytokinin metabolism upon nodulation

Studying the effect of tissue-specific expression of the

To study the role of pea LysM receptor-like kinase K1 in the coordination of the infection process, starting in epidermis and nodule organogenesis in the root cortex of plants, during the development of rhizobium-legume symbiosis, the genetic constructs in which K1 gene was cloned under the control of tissue-specific promoter pLeEXT1 of tomato Lycopersicon esculentum extensin gene and the constitutive promoter of cauliflower mosaic virus (CaMV35S, cauliflower mosaic virus 35S) were obtained. During the transformation of the Nod- mutant line, the k1-1, with two types of constructs, the restoration of nodule formation was observed, which indicated the possible participation of K1 in the control not only early, but also later stages of symbiosis development in pea

The Role of Nuclear Cardiac Imaging in Infective Endocarditis

Purpose of Review: Infective endocarditis (IE) remains a deadly disease despite improvements in its management. Echocardiography is crucial for the diagnosis of IE; however, its value is operator-dependent and its sensitivity can decrease in the presence of valvular prosthesis. This review aims to provide an overview on the role of nuclear cardiac imaging in the diagnosis of IE. Recent Findings: Among all nuclear cardiac imaging modalities, both radiolabeled leukocyte scintigraphy and 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) have been recently introduced in the guidelines of European Society of Cardiology (ESC) for the management of IE. The ESC guidelines included some minor criteria (mainly clinical), and two different sets of major criteria based on blood culture and imaging, respectively. The positivity of either radiolabeled leukocyte scintigraphy or [18F]FDG-PET/CT images is considered itself a major criterion to diagnose IE. However., nuclear cardiac imaging analysis may be tricky and methodological and technical aspects should be carefully considered. Summary: Available evidence supports the role of nuclear cardiac imaging in the diagnosis and management of IE. However., all practitioners who act within the â\u80\u9cEndocarditis Teamâ\u80\u9d should present a very high level of expertise

PET/MRI in Infection and Inflammation

Hybrid positron emission tomography/magnetic resonance imaging (PET/MR) systems are now more and more available for clinical use. PET/MR combines the unique features of MR including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most of the evidence of the potential clinical utility of PET/MRI is available for neuroimaging. Other areas, where PET/MR can play a larger role include head and neck, upper abdominal, and pelvic tumours. Although the role of PET/MR in infection and inflammation of the cardiovascular system and in musculoskeletal applications are promising, these areas of clinical investigation are still in the early phase and it may be a little longer before these areas reach their full potential in clinical practice. In this review, we outline the potential of hybrid PET/MR for imaging infection and inflammation. A background to the main radiopharmaceuticals and some technical considerations are also included. (C) 2018 Published by Elsevier Inc