Heat-tolerant varieties, such as N22 and Dular, which were used in this study, usually have low yield potential and undesirable plant characteristics but combining them with high yielding and improved rice varieties, ...Heat-tolerant varieties, such as N22 and Dular, which were used in this study, usually have low yield potential and undesirable plant characteristics but combining them with high yielding and improved rice varieties, new heat-tolerant rice genotypes with high yield potential can be achieved. In this study, phenotyping and selecting desirable materials from various crosses were performed under high temperature conditions during the reproductive stage. Screening was performed in the field and glasshouse to select individuals with heat tolerance and high yield potential. Several advanced breeding lines from Gayabyeo/N22 cross produced desirable individuals with heat tolerance, resistance to pests and diseases, and high yield potential. The genetic variation in percent sterility among the selected backcross populations grown in high temperature environments showed that large number of plants can be identified and selected with lower percent sterility.展开更多
Previously, we found 123 transcription factors（TFs） as candidate regulators of secondary cell wall（SCW）formation in rice by using phylogenetic and co-expression network analyses. Among them, we examined in this wo...Previously, we found 123 transcription factors（TFs） as candidate regulators of secondary cell wall（SCW）formation in rice by using phylogenetic and co-expression network analyses. Among them, we examined in this work the role of OsIDD_2, a zinc finger and indeterminate domain（IDD） family TF. Its overexpressors showed dwarfism, fragile leaves, and decreased lignin content, which are typical phenotypes of plants defective in SCW formation, whereas its knockout plants showed slightly increased lignin content.The RNA-seq and quantitative reverse transcription polymerase chain reaction analyses confirmed that some lignin biosynthetic genes were downregulated in the OsIDD_2-overexpressing plants, and revealed the same case for other genes involved in cellulose synthesis and sucrose metabolism. The transient expression assay using rice protoplasts revealed that OsIDD_2 negatively regulates the transcription of genes involved in lignin biosynthesis, cinnamyl alcohol dehydrogenase 2 and 3（CAD_2 and 3）, and sucrose metabolism, sucrose synthase 5（SUS_5）, whereas an Alpha Screen assay, which can detect the interaction between TFs and their target DNA sequences, directly confirmed the interaction between OsIDD_2 and the target sequences located in the promoter regions of CAD_2 and CAD_3. Based on these observations, we conclude that OsIDD_2 is negatively involved in SCW formation and other biological events by downregulating its target genes.展开更多
基金supported by the ASEAN-Korea Economic Cooperation Fundthe Ministry of Foreign Affairs and Trade, South Koreathe Rural Development Administration, Republic of Korea
文摘Heat-tolerant varieties, such as N22 and Dular, which were used in this study, usually have low yield potential and undesirable plant characteristics but combining them with high yielding and improved rice varieties, new heat-tolerant rice genotypes with high yield potential can be achieved. In this study, phenotyping and selecting desirable materials from various crosses were performed under high temperature conditions during the reproductive stage. Screening was performed in the field and glasshouse to select individuals with heat tolerance and high yield potential. Several advanced breeding lines from Gayabyeo/N22 cross produced desirable individuals with heat tolerance, resistance to pests and diseases, and high yield potential. The genetic variation in percent sterility among the selected backcross populations grown in high temperature environments showed that large number of plants can be identified and selected with lower percent sterility.
基金supported by grants from Grant-in-Aid for JSPS Research Fellow (JP15J03980 to H.Y.)Series of single-year grants (26-1393 to K.H.)+1 种基金Grants-in-Aid for Scientific Research on Innovative Areas (No.3806 to M.M. and M. U.-T.)the Grant-in-Aid for Scientific Research (A) (JP26252001 to M.M.) and (B) (JP16H04907 to M. U.-T.)
文摘Previously, we found 123 transcription factors（TFs） as candidate regulators of secondary cell wall（SCW）formation in rice by using phylogenetic and co-expression network analyses. Among them, we examined in this work the role of OsIDD_2, a zinc finger and indeterminate domain（IDD） family TF. Its overexpressors showed dwarfism, fragile leaves, and decreased lignin content, which are typical phenotypes of plants defective in SCW formation, whereas its knockout plants showed slightly increased lignin content.The RNA-seq and quantitative reverse transcription polymerase chain reaction analyses confirmed that some lignin biosynthetic genes were downregulated in the OsIDD_2-overexpressing plants, and revealed the same case for other genes involved in cellulose synthesis and sucrose metabolism. The transient expression assay using rice protoplasts revealed that OsIDD_2 negatively regulates the transcription of genes involved in lignin biosynthesis, cinnamyl alcohol dehydrogenase 2 and 3（CAD_2 and 3）, and sucrose metabolism, sucrose synthase 5（SUS_5）, whereas an Alpha Screen assay, which can detect the interaction between TFs and their target DNA sequences, directly confirmed the interaction between OsIDD_2 and the target sequences located in the promoter regions of CAD_2 and CAD_3. Based on these observations, we conclude that OsIDD_2 is negatively involved in SCW formation and other biological events by downregulating its target genes.
