Transcriptome analysis of phosphorus stress responsiveness in the seedlings of Dongxiang wild rice (Oryza rufipogon Griff.).

BACKGROUND: Low phosphorus availability is a major factor restricting rice growth. Dongxiang wild rice (Oryza rufipogon Griff.) has many useful genes lacking in cultivated rice, including stress resistance to phosphorus deficiency, cold, salt and drought, which is considered to be a precious germplasm resource for rice breeding. However, the molecular mechanism of regulation of phosphorus deficiency tolerance is not clear. RESULTS: In this study, cDNA libraries were constructed from the leaf and root tissues of phosphorus stressed and untreated Dongxiang wild rice seedlings, and transcriptome sequencing was performed with the goal of elucidating the molecular mechanisms involved in phosphorus stress response. The results indicated that 1184 transcripts were differentially expressed in the leaves (323 up-regulated and 861 down-regulated) and 986 transcripts were differentially expressed in the roots (756 up-regulated and 230 down-regulated). 43 genes were up-regulated both in leaves and roots, 38 genes were up-regulated in roots but down-regulated in leaves, and only 2 genes were down-regulated in roots but up-regulated in leaves. Among these differentially expressed genes, the detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in phosphorus deficiency tolerance. Meanwhile, the differentially expressed genes were also annotated with gene ontology terms and key pathways via functional classification and Kyoto Encyclopedia of Gene and Genomes pathway mapping, respectively. A set of the most important candidate genes was then identified by combining the differentially expressed genes found in the present study with previously identified phosphorus deficiency tolerance quantitative trait loci. CONCLUSION: The present work provides abundant genomic information for functional dissection of the phosphorus deficiency resistance of Dongxiang wild rice, which will be help to understand the biological regulatory mechanisms of phosphorus deficiency tolerance in Dongxiang wild rice.

Transcriptome analysis of phosphorus stress responsiveness in the seedlings of Dongxiang wild rice (Oryza rufipogon Griff.)

Abstract Background: Low phosphorus availability is a major factor restricting rice growth. Dongxiang wild rice (Oryza rufipogon Griff.) has many useful genes lacking in cultivated rice, including stress resistance to phosphorus deficiency, cold, salt and drought, which is considered to be a precious germplasm resource for rice breeding. However, the molecular mechanism of regulation of phosphorus deficiency tolerance is not clear. Results: In this study, cDNA libraries were constructed from the leaf and root tissues of phosphorus stressed and untreated Dongxiang wild rice seedlings, and transcriptome sequencing was performed with the goal of elucidating the molecular mechanisms involved in phosphorus stress response. The results indicated that 1184 transcripts were differentially expressed in the leaves (323 up-regulated and 861 down-regulated) and 986 transcripts were differentially expressed in the roots (756 up-regulated and 230 down-regulated). 43 genes were up-regulated both in leaves and roots, 38 genes were up-regulated in roots but down-regulated in leaves, and only 2 genes were down-regulated in roots but up-regulated in leaves. Among these differentially expressed genes, the detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in phosphorus deficiency tolerance. Meanwhile, the differentially expressed genes were also annotated with gene ontology terms and key pathways via functional classification and Kyoto Encyclopedia of Gene and Genomes pathway mapping, respectively. A set of the most important candidate genes was then identified by combining the differentially expressed genes found in the present study with previously identified phosphorus deficiency tolerance quantitative trait loci. Conclusion: The present work provides abundant genomic information for functional dissection of the phosphorus deficiency resistance of Dongxiang wild rice, which will be help to understand the biological regulatory mechanisms of phosphorus deficiency tolerance in Dongxiang wild rice.

Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl) phthalate and genistein.

Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl) phthalate (DEHP) and genistein (GEN) during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday). The outcomes studied were general morphometry (weight, AGD), testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday), GEN(50mg/kg bwday) or GEN(400mg/kg bwday) alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday) together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday). When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday) together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP-GEN mixture on adult offspring should be observed further.

Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl) phthalate and genistein

Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl) phthalate (DEHP) and genistein (GEN) during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday). The outcomes studied were general morphometry (weight, AGD), testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday), GEN(50mg/kg bwday) or GEN(400mg/kg bwday) alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday) together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday). When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday) together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP-GEN mixture on adult offspring should be observed further.