OsSYP121 Accumulates at Fungal Penetration Sites and Mediates Host Resistance to Rice Blast.

Magnaporthe oryzae is a fungal pathogen that causes rice (Oryza sativa) blast. SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) are key components in vesicle trafficking in eukaryotic cells and are known to contribute to fungal pathogen resistance. Syntaxin of Plants121 (SYP121), a Qa-SNARE, has been reported to function in nonhost resistance in Arabidopsis (Arabidopsis thaliana). However, the functions of SYP121 in host resistance to rice blast are largely unknown. Here, we report that the rice SYP121 protein, OsSYP121, accumulates at fungal penetration sites and mediates host resistance to rice blast. OsSYP121 is plasma membrane localized and its expression was obviously induced by the rice blast in both the blast-resistant rice landrace Heikezijing and the blast-susceptible landrace Suyunuo (Su). Overexpression of OsSYP121 in Su resulted in enhanced resistance to blast. Knockdown of OsSYP121 expression in Su resulted in a more susceptible phenotype. However, knockdown of OsSYP121 expression in the resistant landrace Heikezijing resulted in susceptibility to the blast fungus. The POsSYP121 ::GFP-OsSYP121 accumulated at rice blast penetration sites in transgenic rice, as observed by confocal microscopy. Yeast two-hybrid results showed that OsSYP121 can interact with OsSNAP32 (Synaptosome-associated protein of 32 kD) and Vesicle-associated membrane protein714/724. The interaction between OsSYP121 and OsSNAP32 may contribute to host resistance to rice blast. Our study reveals that OsSYP121 plays an important role in rice blast resistance as it is a key component in vesicle trafficking.

Cryopreservation-induced decrease in heat-shock protein 90 in human spermatozoa and its mechanism.

AIM: To study the protein changes of spermatozoa associated with sperm motility during sperm cryopreservation and its mechanism. METHODS: In 18 healthy men, the seminal sperm motility and HSP90 levels were studied before and after cryopreservation using SDS-PAGE, Western blotting and computerized image analysis. RESULTS: The sperm motility declined significantly after cryopreservation (P<0.01). The average grey level and the integrated grey level of sperm HSP90 before cooling were 34.1+/-3.2 and 243.0+/-21.6, respectively, while those after thawing were 23.2+/-2.5 and 105.7+/-28.5, respectively. Both parameters were decreased significantly (P<0.01). No HSP90 was found in the seminal plasma before and after cryopreservation. CONCLUSION: HSP90 in human spermatozoa was decreased substantially after cryopreservation. This may result from protein degradation, rather than leakage into the seminal plasma.

[Progression of semen cryopreservation and its relationship with assisted reproductive technology].

The aim of semen cryopreservation research is to elevate the proportion of competent spermatozoa after thawing. By means of molecular biology, the research of spermatozoa injury during cryopreservation reaches molecular level. In each stage of cryopreservation, there exists its own optimal condition for cooling. Cryopreservation medium still need to be improved. Men should pay more attention to the field of spermatozoa function. Assisted reproductive technology (ART) has a close relationship with the technology of semen cryopreservation. The latter's development will improve the former.

[Effect of aging on male sexual function in 93 patients using international index of erectile function].

OBJECTIVES: To investigate the influence of aging on male sexual function. METHODS: The study selected 93 ED patients, aged from 23 to 64, who responded to the International Index of Erectile Function (IIEF) questionnaire. The questionnaire includes 15 items related to male sexual activity, which are organized into 5 domains, namely, erectile function (EF), orgasmic function (OF), sexual desire (SD), intercourse satisfaction (IS) and overall satisfaction (OS). For statistical analysis, ANOVA with DUNCAN test was conducted, and statistical significance was set at P < 0.05. Some other risk factors of ED such as hypertension, diabetes etc. had been excluded. RESULTS: According to the age, the subjects were divided into 5 groups. With age increasing, the proportion of moderate and severe in each group increased from 16.17% to 57.14%, whereas EF score decreased from (19.50 +/- 4.64) to (15.27 +/- 5.64), OF score decreased from (6.93 +/- 2.86) to (5.62 +/- 2.94), SD score decreased from (6.33 +/- 1.63) to (4.50 +/- 2.94), IS score decreased from (10.17 +/- 1.94) to (6.93 +/- 2.90), OS score decreased from (5.00 +/- 0.89) to (3.15 +/- 1.84). The tendency took on linearity (P < 0.01). Aging was negatively correlated to above mentioned scores (r = 0.98, P < 0.01). CONCLUSION: Aging could be thought as a risk factor of ED, which is negatively correlated with male's EF, OF, IS, OS and SD scores, furthermore. IIEF questionnaire is a useful tool assessing epidemiology of ED.

Overexpression of the Qc-SNARE gene OsSYP71 enhances tolerance to oxidative stress and resistance to rice blast in rice (Oryza sativa L.).

OsSYP71 is an oxidative stress and rice blast response gene that encodes a Qc-SNARE protein in rice. Qc-SNARE proteins belong to the superfamily of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors), which function as important components of the vesicle trafficking machinery in eukaryotic cells. In this paper, 12 Qc-SNARE genes were isolated from rice, and expression patterns of 9 genes were detected in various tissues and in seedlings challenged with oxidative stresses and inoculated with rice blast. The expression of OsSYP71 was clearly up-regulated under these stresses. Overexpression of OsSYP71 in rice showed more tolerance to oxidative stress and resistance to rice blast than wild-type plants. These results indicate that Qc-SNAREs play an important role in rice response to environmental stresses, and OsSYP71 is useful in engineering crop plants with enhanced tolerance to oxidative stress and resistance to rice blast.