Identification and molecular mapping of Flowering Date1 (FD1), a major photoperiod insensitivity gene in the adzuki bean (Vigna angularis)

The induction of flowering under long‐day conditions is an important adaptation by short‐day plants, such as adzuki beans (Vigna angularis), to high‐latitude environments. This study clarified the genetic control underlying the long‐day insensitivity of adzuki bean cultivar ‘Shumari’. ‘Shumari’ was found to be insensitive to a 16‐h day, whereas landrace Acc2265 was highly sensitive. When grown under natural long‐day conditions at Obihiro (42°9′N), Acc2265 initiated flowering at least 80 days after ‘Shumari’. When 86 recombinant inbred lines (RILs) derived from crosses between ‘Shumari’ and Acc2265 were grown under these conditions, their flowering dates ranged from the middle of July to the end of October. The distinct bimodal distribution in the RIL population was due to a single major gene, designated Flowering Date1 (FD1). Molecular mapping showed that FD1 was located between the SSR markers Az02‐37M3 and Az02‐40M9, at distances of 6 and 10.4 cM, respectively, on linkage group 2. RILs carrying FD1^S lacked long‐day sensitivity, whereas RILs carrying FD1^A were sensitive to long‐day conditions, confirming that FD1 controls long‐day sensitivity.     

Analysis of Host Species Specificity of Magnaporthe grisea Toward Foxtail Millet Using a Genetic Cross Between Isolates from Wheat and Foxtail Millet

ABSTRACT Host species specificity of Magnaporthe grisea toward foxtail millet was analyzed using F(1) cultures derived from a cross between a Triticum isolate (pathogenic on wheat) and a Setaria isolate (pathogenic on foxtail millet). On foxtail millet cvs. Beni-awa and Oke-awa, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that a single locus is involved in the specificity. This locus was designated as Pfm1. On cv. Ki-awa, two loci were involved and one of them was Pfm1. The other locus was designated as Pfm2. Interestingly, Pfm1 was not involved in the pathogenic specificity on cv. Kariwano-zairai. These results suggest that there is no "master gene" that determines the pathogenic specificity on all foxtail millet cultivars and that the species specificity of M. grisea toward foxtail millet is governed by cultivar-dependent genetic mechanisms that are similar to gene-for-gene interactions controlling race-cultivar specificity.     

Synthesis and herbicidal activity of new oxazinone herbicides with a long-lasting herbicidal activity against Echinochloa oryzicola

Chemical modification of the herbicide 1-[2-(benzothiazol-2-yl)isopropyl]-4-methyl-3-phenyl-5H-pyrrolin-2-one (MI-2826) has revealed a new oxazinone herbicide, 3-[2-(7-chlorobenzothiazol-2-yl)isopropyl]-2,3-dihydro-6-methyl-5-phenyl-4H-1,3-oxazin-4-one (MI-3069), for use in paddy fields. In comparing the phyototoxicity of the two herbicides to transplanted rice, the latter was superior to the former and kept the same predominant characteristic to control Echinochloa oryzicola Vasin for a long period of time owing to its long-lasting residual effect.     

Cellular functions of mitogen-activated protein kinases and protein tyrosine phosphatases in ovarian granulosa cells

A number of endocrine and paracrine factors regulate the follicular growth and atresia, which are closely associated with granulosa cell survival and apoptosis. However, the molecular mechanisms underlying the intracellular events induced by these factors are poorly understood. Here, we describe the correlation of mitogen-activated protein kinase (MAPK) activities with granulosa cell survival and apoptosis, and the cellular functions of protein tyrosine phosphatases (PTPs) in these cells based on our recent data. MAPKs play key roles in various cellular responses because numerous extracellular stimuli are integrated into MAPKs. The protein phospho-Tyr level regulated by protein tyrosine kinases (PTKs) and PTPs is a major control mechanism for processes as diverse as cell survival, proliferation, differentiation, and metabolism. Although PTKs are critically involved in granulosa cell survival and proliferation, there are no reports indicating the roles of PTPs in the ovary except for ours. Information about MAPKs and PTPs in these cells will provide a basis for the understanding of the molecular mechanisms controlling the fate of follicles.     

Genetic Constitution and Pathogenicity of Lolium Isolates of Magnaporthe oryzae in Comparison with Host Species-Specific Pathotypes of the Blast Fungus

ABSTRACT Fungal isolates from gray leaf spot on perennial ryegrass (prg isolates) were characterized by DNA analyses, mating tests, and pathogenicity assays. All of the prg isolates were interfertile with Triticum isolates and clustered into the crop isolate group (CC group) on a dendrogram constructed from rDNA-internal transcribed spacer 2 sequences. Since the CC group corresponded to a newly proposed species, Magnaporthe oryzae, all of the prg isolates were designated M. oryzae. However, DNA fingerprinting with MGR586, MGR583, and Pot2 showed that the prg isolates are divided into two distinct populations, i.e., TALF isolates and WK isolates. The TALF isolates were virulent only on Lolium species, whereas the WK isolates were less specific, suggesting that gray leaf spot can be caused not only by Lolium-specific isolates but also by less specific isolates. We designated the TALF isolates as Lolium pathotype. The TALF isolates showed diverse karyotypes in spite of being uniform in DNA fingerprints, suggesting that theyare unstable in genome organization.     

Granulocyte responses to experimental injection of live and formalin-killed bacteria in carp (Cyprinus carpio)

The objective of the study was to investigate the dynamics of changes in number of granulocytes in bacterial infections of carp (Cyprinus carpio). Carp were inoculated with non-pathogenic or pathogenic bacteria and changes in type I (neutrophils) and type II granulocyte (basophils/eosinophils) counts in kidney, circulating blood and peritoneal cavity were assessed. After the injection of non-pathogenic bacteria (Escherichia coli), the number of type I and II cells in blood increased after 6-12h, but returned to the control level after 24-48 h. In contrast, after the injection of pathogenic bacteria (Aeromonas hydrophila), the number of type I cells initially increased followed by an increase in the number of type II cells. The peak counts of type I and II cells were at 12 and 24h after the injection, respectively. When the fish were given serial-injections of formalin-killed bacteria at 12-h intervals, the type II cells also predominantly increased and remained at high levels, following the peak count of type I cells.     

Sequence comparison of the dopamine receptor D4 exon III repetitive region in several species of the order Carnivora

It was previously demonstrated that the dog dopamine receptor D4 (DRD4) gene is polymorphic in terms of the repeat number and/or order of 39- and 12-bp sequences located in the third exon. To examine whether or not the repetitive region is present in other species of the order Carnivora, the homologous region of DRD4 genes were sequenced in the gray wolf, raccoon dog, Asiatic black bear, common raccoon and domestic cat. In the family Canidae, the wolf had an identical sequence to that of the dog 447b allele, and a repetitive sequence similar to the dog DRD4 was also recognized in the raccoon dog. On the other hand, no obvious repeated structure was observed in the sequences of the bear, raccoon and cat.     

Inhibitory effects of epigallocatechin gallate on the propagation of bovine coronavirus in Madin-Darby bovine kidney cells

Epigallocatechin gallate (EGCg) is the main active component of tea polyphenol and shows several biological activities, such as antimicrobial, antitumor‐promoting, anti‐inflammatory and anti‐oxidative activities. In the present study, the inhibitory effect of EGCg on bovine coronavirus (BCV) propagation in Madin‐Darby bovine kidney (MDBK) cells was investigated. EGCg at concentrations of less than 10 µg/mL did not show any cytotoxicity to MDBK cells. BCV propagation was significantly inhibited by pretreatment of the virus with EGCg (0.5–10 µg/mL) before virus inoculation in dose‐dependent, incubation time‐dependent and temperature‐dependent manners. The antiviral effect of pretreating MDBK cells with EGCg on BCV propagation was much weaker than that of pretreating BCV with EGCg. The hemagglutination activity of BCV was also reduced by EGCg in a dose‐dependent manner. These results demonstrate that EGCg possesses a distinct anti‐BCV activity and strongly suggest that EGCg interferes with the adsorption of BCV to MDBK cells by the interaction of EGCg with BCV particles. EGCg may therefore be a useful candidate for controlling BCV infection more effectively.     

Nitric oxide-overproducing transformants of Pseudomonas fluorescens with enhanced biocontrol of tomato bacterial wilt

The relation between nitric oxide (NO) production and the protective ability of Pseudomonas fluorescens T5 against bacterial wilt disease in tomato was examined. The endogenous nitric oxide reductase gene of T5 was disrupted by homologous recombination using a suicide plasmid. Three disruptants were obtained, and all had higher levels of NO production. Infection with Ralstonia solanacearum was reduced in tomato plants treated with the NO-overproducing transformants compared with the wild type. These results suggest that the modification of pseudomonads to increase their level of NO production is a new approach to enhancing their biocontrol efficacy.