Project description:Purpose: The goal of our study is to compare two different ecotypes of Oryza sativa L., PHS-susceptible rice trait and PHS-resistant rice trait under three different maturation stages in rice seed embryo with profile of miRNA-seq. Methods: Oryza sativa. L miRNA profiles of two different ecotypes with 3 different maturation stages of rice seed embryo were generated by NGS, in duplicate, following Illumina NGS workflow. Results: We found the differentially expressed microRNAs between PHS-susceptible rice trait and PHS-resistant rice trait according to the three different seed maturation stages. Target transcripts of differentially expressed microRNAs have been predicted via psRNATarget web server, and a part of those target genes are likely to be regulated by microRNAs, affecting overall responses to heat stress and the regulation of seed dormancy during maturation. Conclusions: Our study represents the analysis of rice seed small RNAs, specifically microRNAs, under two different ecotypes, three different seed maturation stages in rice seed embryo. Our results show that microRNAs are involved in response to heat stress and the regulation of seed dormancy. This study will provide a foundation for understanding dynamics of seed dormancy during the seed development and overcoming pre-harvest sprouting.
Project description:affy_rice_2012_01 - ovation - One of the key questions for future agriculture will be to save agronomical relevant biodiversity. To do so, it is important to select the best crop cultivars that will germinate efficiently (good seed vigor) and for a long period of time (good seed longevity). Surprisingly, while mankind rely heavily on cereals, very few studies have identified genes positively related to cereal seed vigor and longevity. To close this scientific gap, we aimed to identify genes positively involved in rice seed vigor and longevity. We thus used a “controlled deterioration treatment (Tesnier et al., 2002) to mimic natural seed ageing. Seeds are first equilibrated at 25°C and 85% relative hygrometry during three days. Then, during 15 days, three different batch of seeds are either (i) kept at 25°C and 85% RH (control seeds), (ii) placed at 40°C and 85% RH (loss of seed vigor) or (iii) placed at 45°C and 85% RH (loss of germination capacity). Finally, seeds are equilibrated at 25°C and 32% RH during three days. Using this CDT treatment, we obtained rice seeds with contrasted seed vigor or germination capacity. We extracted the total RNA from the embryos and we analysed their transcriptome using the Affymetrix Rice Genome Array.-We applied a Controlled Deterioration Treatment (CDT) to seeds from the reference rice cultivar Nipponbare. First, all seeds are equilibrated at 25°C and 85% relative hygrometry. Then, depending on the treatment, seeds are placed at 25, 40 or 45°C in 85% relative hygrometry before being finally equilibrated at 25°C and 32% relative hygrometry. The germination of the three seed batches was measured during five days with one measure every 8h. Seeds placed at 25°C during the whole experiment were similar to control seeds kept in the fridge and germinated at nearly 100% in 48h. Seeds placed at 40°C during 15 days germinate at 74% but show altered seedling phenotypes (loss of seed vigor). Finally, seeds placed at 45°C do not germinate. 6 arrays - rice; treated vs untreated comparison
Project description:affy_rice_2012_01 - ivt - One of the key questions for future agriculture will be to save agronomical relevant biodiversity. To do so, it is important to select the best crop cultivars that will germinate efficiently (good seed vigor) and for a long period of time (good seed longevity). Surprisingly, while mankind rely heavily on cereals, very few studies have identified genes positively related to cereal seed vigor and longevity. To close this scientific gap, we aimed to identify genes positively involved in rice seed vigor and longevity. We thus used a “controlled deterioration treatment (Tesnier et al., 2002) to mimic natural seed ageing. Seeds are first equilibrated at 25°C and 85% relative hygrometry during three days. Then, during 15 days, three different batch of seeds are either (i) kept at 25°C and 85% RH (control seeds), (ii) placed at 40°C and 85% RH (loss of seed vigor) or (iii) placed at 45°C and 85% RH (loss of germination capacity). Finally, seeds are equilibrated at 25°C and 32% RH during three days. Using this CDT treatment, we obtained rice seeds with contrasted seed vigor or germination capacity. We extracted the total RNA from the embryos and we analysed their transcriptome using the Affymetrix Rice Genome Array.-We applied a Controlled Deterioration Treatment (CDT) to seeds from the reference rice cultivar Nipponbare. First, all seeds are equilibrated at 25°C and 85% relative hygrometry. Then, depending on the treatment, seeds are placed at 25, 40 or 45°C in 85% relative hygrometry before being finally equilibrated at 25°C and 32% relative hygrometry. The germination of the three seed batches was measured during five days with one measure every 8h. Seeds placed at 25°C during the whole experiment were similar to control seeds kept in the fridge and germinated at nearly 100% in 48h. Seeds placed at 40°C during 15 days germinate at 74% but show altered seedling phenotypes (loss of seed vigor). Finally, seeds placed at 45°C do not germinate. 12 arrays - rice; treated vs untreated comparison
Project description:Melatonin plays a potential role in multiple plant developmental processes and stress response. However, there are no reports regarding exogenous melatonin promoting rice seed germination under salinity and nor about the underlying molecular mechanisms at genome-wide. Here, we revealed that exogenous application of melatonin conferred roles in promoting rice seed germination under salinity. The putative molecular mechanisms of exogenous melatonin in promoting rice seed germination under high salinity were further investigated through metabolomic and transcriptomic analyses. The results state clearly that the phytohormone contents were reprogrammed, the activities of SOD, CAT, POD were enhanced, and the total antioxidant capacity was activated under salinity by exogenous melatonin. Additionally, melatonin-pre-treated seeds exhibited higher concentrations of glycosides than non-treated seeds under salinity. Furthermore, exogenous melatonin alleviated the accumulation of fatty acids induced by salinity. Genome-wide transcriptomic profiling identified 7160 transcripts that were differentially expressed in NaCl, MT100 and control. Pathway and GO term enrichment analysis revealed that genes involved in the response to oxidative stress, hormone metabolism, heme building, mitochondrion, tricarboxylic acid transformation were altered after melatonin pre-treatment under salinity. This study provides the first evidence of the protective roles of exogenous melatonin in increasing rice seed germination under salt stress, mainly via activation of antioxidants and modulation of metabolic homeostasis.
Project description:Purpose: The goal of our study is to compare two different ecotypes of Oryza sativa L., PHS-susceptible rice trait and PHS-resistant rice trait under three different maturation stages and two different tissues, embryo and endosperm of rice seeds with profile of RNA-seq. Methods: Oryza sativa. L mRNA profiles of two different ecotypes with 3 different maturation stages and 2 different tissues were generated by NGS, in duplicate, following Illumina NGS workflow. qRT–PCR validation was performed using SYBR Green assays. Results: We found the differentially expressed genes (DEGs) between PHS-susceptible rice trait and PHS-resistant rice trait according to the three different seed maturation stages. In DEGs, gene ontology (GO) analysis and Mapman analysis were performed, and we discovered genes related to plant hormones and heat stress, which are not yet reported. These genes were validated through qRT-PCR, and it is likely to be highly related to seed dormancy. Conclusions: Our study represents the analysis of rice seed transcriptomes under two different ecotypes, three different seed maturation stages and two different tissues (Embryo and endosperm). Our results show that seed dormancy is affected and regulated by a plant hormones and heat stress. This study might provide a foundation for understanding dynamics of seed dormancy during the seed development and overcoming pre-harvest sprouting.
Project description:affy_rice_2012_01 - ivt - One of the key questions for future agriculture will be to save agronomical relevant biodiversity. To do so, it is important to select the best crop cultivars that will germinate efficiently (good seed vigor) and for a long period of time (good seed longevity). Surprisingly, while mankind rely heavily on cereals, very few studies have identified genes positively related to cereal seed vigor and longevity. To close this scientific gap, we aimed to identify genes positively involved in rice seed vigor and longevity. We thus used a “controlled deterioration treatment (Tesnier et al., 2002) to mimic natural seed ageing. Seeds are first equilibrated at 25°C and 85% relative hygrometry during three days. Then, during 15 days, three different batch of seeds are either (i) kept at 25°C and 85% RH (control seeds), (ii) placed at 40°C and 85% RH (loss of seed vigor) or (iii) placed at 45°C and 85% RH (loss of germination capacity). Finally, seeds are equilibrated at 25°C and 32% RH during three days. Using this CDT treatment, we obtained rice seeds with contrasted seed vigor or germination capacity. We extracted the total RNA from the embryos and we analysed their transcriptome using the Affymetrix Rice Genome Array.-We applied a Controlled Deterioration Treatment (CDT) to seeds from the reference rice cultivar Nipponbare. First, all seeds are equilibrated at 25°C and 85% relative hygrometry. Then, depending on the treatment, seeds are placed at 25, 40 or 45°C in 85% relative hygrometry before being finally equilibrated at 25°C and 32% relative hygrometry. The germination of the three seed batches was measured during five days with one measure every 8h. Seeds placed at 25°C during the whole experiment were similar to control seeds kept in the fridge and germinated at nearly 100% in 48h. Seeds placed at 40°C during 15 days germinate at 74% but show altered seedling phenotypes (loss of seed vigor). Finally, seeds placed at 45°C do not germinate.