Plant hormone-induced defense responses against Botrytis cinerea

Several plant hormones, including ethylene and jasmonates, are known to mediate responses against biotic and abiotic stress. The first and second objectives of this thesis were (i) to elucidate the role of ethylene in defense responses against Botrytis cinerea and specifically (ii) to determine the potential contribution of ethylene response factors (ERFs) to induced resistance. Besides being involved in plant protection, the gaseous plant hormone ethylene is an important developmental signal, controlling fruit ripening and other events. With respect to plant-pathogen interactions ethylene can accelerate or inhibit infection depending on the plant species, organ, or age. Ethylene is known to contribute to foliar resistance against B. cinerea. This pathogen causes gray mold and other diseases. It attacks more than 200 plant species, including apple (Malus domestica) and pear (Pyrus communis). However, effects of ethylene on B. cinerea infection of fruits are not well understood. I specifically examined the role of ethylene in defenses of pome fruits against B. cinerea. Ethylene was manipulated exogenously and endogenously. Inhibition of ethylene action and biosynthesis was found to stimulate infections of pear and apple fruits by B. cinerea, respectively. This implicates ethylene in protecting fruits against B. cinerea. ERFs are known to specifically bind to 'GCC'-boxes of defense-related target gene and to induce foliar resistance against necrotrophic pathogens. To understand the defensive functions of this class of transcription factors in fruits, I characterized members of the ERF gene family in apple. Four MdERF genes, which are expressed in apple fruits, were identified. To determine dependence of gene expression on ethylene, untransformed and ethylene-silenced apples [Dandekar et al. (2004) Transgenic Res. 13: 373-384] were compared. Only one of them, MdERF3, was induced by wounding and B. cinerea infection in ethylene-silenced apple fruits. To test the function of MdERF3, the gene was transiently expressed in tobacco leaves. Elevated expression of MdERF3 was correlated with increased expression of the GCC-box-containing gene Chitinase 48. Thus, MdERF3 appears to be part of the ethylene/pathogenesis-related defense response against B. cinerea in apple fruits. The third objective of my thesis was to investigate interactions between jasmonate and oligogalacturonic acid (OGA) signaling during defense responses against B. cinerea. The Cervone hypothesis [Cervone et al. (1989) Plant Physiol. 90: 542-548] states that OGAs generated from in vitro interactions between fungal polygalacturonases (PGs) and PG-inhibiting proteins (PGIPs) activate phytoalexin biosynthesis and other plant defense responses. I tested the in vivo significance of this hypothesis using genetics. The tomato mutant coi1 with a defect in the jasmonate signaling was crossed to a transgenic line constitutively expressing PGIP from pear. The results suggest that both jasmonates and PGIP independently alter resistance to this fungal pathogen, thus refuting the hypothesis that OGAs activate the jasmonic acid pathway

Epoprostenol sodium for treatment of pulmonary arterial hypertension

　The release of endogenous prostacyclin (PGI2) is depressed in patients with pulmonary arterial hypertension (PAH). PGI2 replacement therapy by epoprostenol infusion is one of the best treatments available for PAH. Here, we provide an overview of the current clinical data for epoprostenol. Epoprostenol treatment improves symptoms, exercise capacity, and hemodynamics, and is the only treatment that has been shown to reduce mortality in patients with idiopathic PAH (IPAH) in randomized clinical trials. We have reported that high-dose epoprostenol therapy (>40 ng/kg/min) also results in marked hemodynamic improvement in some patients with IPAH. High-dose epoprostenol has a pro-apoptotic effect on PAH-PASMCs via the IP receptor and upregulation of Fas ligand (FasL) in vitro. However, long-term intravenous administration of epoprostenol is sometimes associated with catheter-related infections and leads to considerable inconvenience for the patient. In the future, the development of new routes of administration or the development of powerful PGI2 analogs, IP-receptor agonists, and gene and cell-based therapy enhancing PGI2 production with new routes of administration is required

The R2R3-MYB Transcription Factor Gene Family in Maize

MYB proteins comprise a large family of plant transcription factors, members of which perform a variety of functions in plant biological processes. To date, no genome-wide characterization of this gene family has been conducted in maize (Zea mays). In the present study, we performed a comprehensive computational analysis, to yield a complete overview of the R2R3-MYB gene family in maize, including the phylogeny, expression patterns, and also its structural and functional characteristics. The MYB gene structure in maize and Arabidopsis were highly conserved, indicating that they were originally compact in size. Subgroup-specific conserved motifs outside the MYB domain may reflect functional conservation. The genome distribution strongly supports the hypothesis that segmental and tandem duplication contribute to the expansion of maize MYB genes. We also performed an updated and comprehensive classification of the R2R3-MYB gene families in maize and other plant species. The result revealed that the functions were conserved between maize MYB genes and their putative orthologs, demonstrating the origin and evolutionary diversification of plant MYB genes. Species-specific groups/subgroups may evolve or be lost during evolution, resulting in functional divergence. Expression profile study indicated that maize R2R3-MYB genes exhibit a variety of expression patterns, suggesting diverse functions. Furthermore, computational prediction potential targets of maize microRNAs (miRNAs) revealed that miR159, miR319, and miR160 may be implicated in regulating maize R2R3-MYB genes, suggesting roles of these miRNAs in post-transcriptional regulation and transcription networks. Our comparative analysis of R2R3-MYB genes in maize confirm and extend the sequence and functional characteristics of this gene family, and will facilitate future functional analysis of the MYB gene family in maize

Studies on the Clay Minerals in the Area around Togo Lake (Ⅰ)

In this paper, the writers dealed with the mineralogical properties of "clay concretion " which is contained in the strongly efflorescenced tuffuceous andesite in the area around Togō Lakes. Most of the clay concretions have a oval shape and consist of crust and contents. On the origin of such clay concretion shall be discussed in the following paper. The mineralogical properties were investigated by means of X-ray diffraction analysis, differential thermal analysis and electron micrographs. By these investigations it was recognized that the basal clay mineral (strongly efflorescenced tuffuceous andesite) in consisted almost with gibbsite and the protion of crust od concretion is consisted with gibbsite and halloysite hydrated. The inside crust of concretion is consisted almost with halloysitc hydrated. The inner content (dark reddish gray colour) is also consisted with halloysite hydrated but the degrees of crystallization and purity are lower than those of inside crust of concretion

Studies on the Clay Minerals in Koyama Sand-Dune Soils (1)

The mineralogical properties of the clay minerals separated from Koyama sand-dune soil were investigated by means of X-ray diffraction analysis, differential thermal analysis and micrographs. The specimens were collected from the four stratigraphically conspicuous outcrops K-1, K-8, K-17 and K-23 as shown in Fig. 1. By these investigations it was recognized that the pumice bed of Daisen Loam (so-called "Kurayoshi Pumice") is consisted mainly with feldspar and allophane. Other stratums of these outcrops are mainly consisted with quartz. The loams of brownish yelllow colour such as K-1.1, K-1.5, K-17.2, K-17.5, K-23.2 and K-23.5, (Figs.2-5) contain gibbsite. The loams K-1.5, K-8.2, K-17.4 and K-23.5 seems to contain halloysite hydrated

Stress fracture of the second proximal phalanx of the foot in teenage athletes: Unrecognized location of stress fracture

Background: Adolescent athletes are a high-risk population for stress fractures. We report four cases of stress fractures of the second proximal phalanx, which had not been previously diagnosed as the location of the stress fracture of the foot, in teenage athletes. Case report: All fractures were on the plantar side of the proximal phalangeal base, and the oblique images of the plain radiograph clearly depicted the fractures. Notably, three out of the four patients had histories of stress fracture of other locations. While three athletes with acute cases were able to make an early return to play with simple conservative management, the chronic case required surgical treatment for this rare injury. Conclusion: Although a rare injury, it is important that clinicians be aware of this type of stress fracture, as a timely diagnosis can avoid the need for surgical treatment and allow an early return to play

Additional file 2: of Exogenous proteinogenic amino acids induce systemic resistance in rice

Concentrations of amino acids in rice leaves. (PDF 187 kb