Raspberry bushy dwarf virus (RBDV) is transmitted through seed in infected red raspberry plants after pollination with pollen grains from healthy red raspberry plants. Here, we show that RBDV is not transmitted through seeds in infected Nicotiana benthamiana (Nb) plants after pollination with virus-free Nb pollen grains. Chromogenic in situ hybridization revealed that the virus invades the shoot apical meristem and the ovule, including the embryo sac, of RBDV-infected Nb plants; however, in seeds that developed from infected embryo sacs after fertilization by virus-free sperm cells, RBDV was absent in the embryos and present in the endosperms.
View Article and Find Full Text PDFPlant Biotechnol (Tokyo)
September 2021
In various coastal areas of Japan, naturalized radish populations are observed. Radish is a cruciferous plant and exhibits self-incompatibility, involving a system controlled by a single locus with multiple S alleles. Although the S allele diversity of radish cultivars and wild radishes has been characterized, the S allele distribution in naturalized populations has not yet been analyzed in relation to the positions of the plants in situ.
View Article and Find Full Text PDFFront Plant Sci
September 2020
Self-compatibility in represents the relatively recent disruption of ancestral obligate cross pollination, recognized as one of the prevalent evolutionary pathways in flowering plants, as noted by Darwin. Our previous study found that inversion of the male specificity gene (/) disrupted self-incompatibility, which was restored by overexpressing the with the reversed inversion. However, in has other mutations aside from the pivotal inversion, in both promoter and coding regions, with probable effects on transcriptional regulation.
View Article and Find Full Text PDFSelf-incompatibility (SI) is a sophisticated system for pollen selectivity to prevent pollination by genetically identical pollen. In Brassica, it is genetically controlled by a single, highly polymorphic S-locus, and the male and female S-determinant factors have been identified as S-locus protein 11 (SP11)/S-locus cysteine-rich protein (SCR) and S-locus receptor kinase (SRK), respectively. However, the overall molecular system and identity of factors in the downstream cascade of the SI reaction remain unclear.
View Article and Find Full Text PDFFloral thermogenesis has been found in dozens of primitive seed plants and the reproductive organs in these plants produce heat during anthesis. Thus, characterization of the molecular mechanisms underlying flowering is required to fully understand the role of thermogenesis, but this aspect of thermogenic plant development is largely unknown. In this study, extensive database searches and cloning experiments suggest that thermogenic skunk cabbage (Symplocarpus renifolius), which is a member of the family Araceae, possesses two genes encoding phosphatidyl ethanolamine-binding proteins (PEBP), FLOWERING LOCUS T (SrFT) and MOTHER OF FT AND TFL1 (SrMFT).
View Article and Find Full Text PDFPlants subjected to abiotic stress can regulate gene expression post-transcriptionally by means of small RNAs such as microRNAs. Cool-temperature stress causes abnormal tapetum hypertrophy in rice anthers, leading to pollen sterility. As a first step toward understanding the molecular mechanisms of cool tolerance in developing anthers of rice, we report here a comprehensive comparative analysis of microRNAs between cool-sensitive Sasanishiki and cool-tolerant Hitomebore cultivars.
View Article and Find Full Text PDFPollination is an important early step in sexual plant reproduction. In Arabidopsis thaliana, sequential pollination events, from pollen adhesion onto the stigma surface to pollen tube germination and elongation, occur on the stigmatic papilla cells. Following successful completion of these events, the pollen tube penetrates the stigma and finally fertilizes a female gametophyte.
View Article and Find Full Text PDFPollination is an early and critical step in plant reproduction, leading to successful fertilization. It consists of many sequential processes, including adhesion of pollen grains onto the surface of stigmatic papilla cells, foot formation to strengthen pollen-stigma interaction, pollen hydration and germination, and pollen tube elongation and penetration. We have focused on an examination of the expressed genes in papilla cells, to increase understanding of the molecular systems of pollination.
View Article and Find Full Text PDFBackground And Aims: Pollination is an important process in the life cycle of plants and is the first step in bringing together the male and female gametophytes for plant reproduction. While pollination has been studied for many years, accurate knowledge of the morphological aspects of this process is still far from complete. This study therefore focuses on a morphological characterization of pollination, using time-series image analysis of self- and cross-pollinations in Brassica rapa.
View Article and Find Full Text PDFIn plant reproduction, pollination is the initial key process in bringing together the male and female gametophytes. When a pollen grain lands on the surface of the stigma, information is exchanged between the pollen and stigmatic cell to determine whether the pollen grain will be accepted or rejected. If it is accepted, the stigmatic papilla cell supplies water and other resources to the pollen for germination and pollen tube elongation.
View Article and Find Full Text PDFTumor-bearing mice showed a significant resistance against Candida albicans intravenous infection. Longer survival was observed in groups of mice inoculated with fungal cells 2-3 weeks after tumor transplantation with allogeneic sarcoma 180, syngeneic methylcholanthrene-induced Meth A fibrosarcoma, and MM 46 mammary carcinoma than in non-tumor-bearing mice inoculated only with fungal cells. This effect was not observed when the mice were infected only 1 week after tumor transplantation.
View Article and Find Full Text PDFWe conducted a comparative study of the protective effects of chitin, chitosan, and N-acetyl chitohexaose (NACOS-6) against mice infected intravenously or intraperitoneally with Pseudomonas aeruginosa and Listeria monocytogenes. Mice pretreated with chitin, chitosan, and NACOS-6 showed resistance to intraperitoneal infections by both microbes. Only mice pretreated with chitin and chitosan showed resistance to intravenous infections by both microbes.
View Article and Find Full Text PDFWe investigated the production of interleukin-1 (IL-1) activity by Kupffer cells (KC) from mice treated with a neutral mannan fraction (WNM) or an acidic mannan fraction (WAM025) from baker's yeast (Saccharomyces cerevisiae) in vivo and in vitro. The mice administered WAM025 showed an increase in the number of KC and the IL-1 production compared with mice administered WNM. In an in vitro stimulation assay using KC from a normal mouse, it was also found that WAM025 displayed an increase in IL-1 production.
View Article and Find Full Text PDFFEMS Immunol Med Microbiol
October 2002
A longer survival and a decrease in the number of fungal cells in kidneys and brain were observed in groups of mice inoculated with Aspergillus fumigatus conidia 2-3 weeks (especially 3 weeks) after sarcoma 180 tumor transplantation compared to groups of non-tumor-bearing (control) mice inoculated with fungal cells only. The 3-4-week tumor-bearing mice had significantly decreased levels of serum iron and increased levels of unbound iron binding capacity in the serum compared to those of the non-tumor-bearing mice.
View Article and Find Full Text PDFThe culture supernatant of Candida albicans promoted the disruption of human red blood cells (RBCs). The haemolytic activity was detected in a sugar-rich fraction (about 200 kDa) from Sephacryl S-100 chromatography. As the haemolytic activity was adsorbed by concanavalin A-Sepharose, the haemolytic factor may be a mannoprotein.
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