Molecular epidemiology of <Emphasis Type="Italic">Pseudomonas syringae</Emphasis> pv. <Emphasis Type="Italic">syringae</Emphasis> strains isolated from barley and wheat infected with bacterial black node

A repetitive sequence-based (rep)-polymerase chain reaction (PCR) and inter-simple sequence repeat (ISSR)-PCR were used to molecular type Pseudomonas syringae pv. syringae (PSS) strains isolated from barley and wheat plants with bacterial black node symptoms grown in 22 different locations and six different seed-production districts in Japan. Eighteen genomic fingerprinting (GF) genotypes were obtained from the combined results of BOX-, REP-, and GTG₅-PCR, indicating that the PSS population in Japan has high genetic diversity. The result based on logistic regression indicated that the population of GF genotype A was significantly related to a seed-producing district and that the epidemic of PSS strains in fields originated mainly from seed infection. This study will be applicable to future studies of the molecular epidemiology of bacterial plant diseases that have multiple infection routes.     

Trichomes: interaction sites of tomato leaves with biotrophic powdery mildew pathogens

The present study aimed to explore the possibility of using the type I trichomes of tomato (Solanum lycopersicum) to monitor the infection processes of powdery mildews by microscopy. Individual trichome cells of two tomato genotypes were inoculated with pathogenic and non-pathogenic powdery mildew species, Pseudoidium neolycopersici, Erysiphe trifoliorum and Podosphaera xanthii. On the trichome cells of the tomato cultivar Moneymaker, hyphae of the pathogenic Pseudoidium neolycopersici (isolates KTP-03 and KTP-04) grew vigorously; whereas hyphal growth of the non-pathogenic Erysiphe trifoliorum and Podosphaera xanthii ceased after appressorium formation, which was associated with papilla formation and hypersensitive cell death, respectively. Similar infection processes of the tested powdery mildews were seen in Moneymaker epidermal cells. Therefore, tomato trichomes are suitable for analysing, at individual cell level, the infection processes of different pathotypes of powdery mildews and for observing the cytological responses of plants by non-pathogenic powdery mildews. On the other hand, it was observed that both isolates KTP-03 and KTP-04 failed to produce conidiophores on the hyphae elongating on Moneymaker trichomes. Similarly, no conidiophores were produced on the hyphae elongating on trichomes of Solanum peruvianum LA2172, which is resistant to KTP-03 and susceptible to KTP-04. Interestingly, delayed cell death occurred in LA2172 epidermal cells, which were attacked by KTP-03 hyphae elongating from trichomes and conidiophores were formed on new hyphae growing from the leaf epidermal cells. Thus, leaf trichomes and epidermal cells of the wild tomato species LA2172 reacted differently to the avirulent isolate KTP-03.     

Evaluation of bovine uterine gland functions in 2D and 3D culture system

In ruminants, uterine glands play key roles in the establishment of pregnancy by secreting various factors into the uterine lumen. Although a three-dimensional (3D) culture system has been used for investigating cellular functions in vitro, the detailed functions of uterine gland have not been fully elucidated. In this study, we examined the benefits of 3D culture system to examine the innate functions of bovine uterine glands. Isolated bovine uterine glands were cultured on Matrigel (2D) or in Matrigel (3D), respectively, and the mRNA levels of secreted proteins (SERPINA14, MEP1B, APOA1, ARSA, CTGF, and SPP1) were measured in isolated and cultured uterine glands. The protein expression of estrogen receptor β (ERβ) and progesterone receptor (PR) and the establishment of apico-basal polarity were examined. In isolated uterine glands, the mRNA levels of secreted proteins changed during the estrous cycle. Although uterine glands cultured in both 2D and 3D expressed ERβ and PR, progesterone did not affect SERPINA14 mRNA expression. The expression of APOA1 mRNA in 2D cultured uterine glands did not respond to estrogen and progesterone. Additionally, the mRNA levels of secreted proteins in the 3D culture system were significantly higher than those in the 2D culture system, which might be attributed to the different cellular morphology between them. The locations of ZO-1 and β-catenin in 2D cultured uterine glands were disordered compared with 3D cultured uterine glands. These results showed that the hormonal responsiveness of secreted factor expression and cellular morphology were different between 2D and 3D cultured bovine uterine glands.