A novel tapetum-specific cDNA clone of rice, its corresponding gene designed as RA39, is isolated by RNA subtractive hybridization, differential screening and rapid amplification of cDNA ends. The RA39 cDNA is 1013 bp...A novel tapetum-specific cDNA clone of rice, its corresponding gene designed as RA39, is isolated by RNA subtractive hybridization, differential screening and rapid amplification of cDNA ends. The RA39 cDNA is 1013 bp in length with an open reading frame encoding 298 amino acid residues. mRNA in situ hybridization reveals that RA39 is a tapetum-specific gene, and highly expressed at the meiosis stage of pollen mother cells. The deduced protein contains a signal peptide, a transmembrane region and a cytoplasmic tail, and is predicted to localize in endoplasmic reticulum by PSORT program. This cDNA sequence did not show significant homology to any known sequences in Genbank database. RA39 is the first gene identified to be expressed specifically in tapetal cells at the meiosis stage of pollen mother cells from cereals.展开更多
The Arabidopsis AtMYB103 gene is required for anther development,but whether the homologous gene in rice has the same role is unclear.Sequence analysis indicated that the rice OsMYB103 gene shares a high sequence simi...The Arabidopsis AtMYB103 gene is required for anther development,but whether the homologous gene in rice has the same role is unclear.Sequence analysis indicated that the rice OsMYB103 gene shares a high sequence similarity with AtMYB103.Therefore,we investigated the functional role of OsMYB103 in anther development using an RNAi approach.The OsMYB103 RNA transcript was expressed most abundantly in flowers,specifically in the tapetum,premeiotic pollen mother cells,and meiotic PMCs.OsMYB103-RNAi transgenic lines grew normally during their vegetative phase but displayed reduced male fertility,a phenotype that was associated with downregulated OsMYB103 transcript levels.Expression of OsMS2,an ortholog of the Arabidopsis AtMS2 gene,was also dramatically reduced in the transgenic plants.Knockdown of OsMYB103 led to defects in tapetum development,and most of the microspores in mature anthers lacked exines.Moreover,OsMYB103 could partially rescue the male sterility phenotype of an AtMYB103 knockout mutant ms188.Taken together,these results indicate that OsMYB103 does have an important role in rice tapetum and microspore development.展开更多
During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-...During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-MS1） for tapetal development and function. DEFECTIVE in TAPETAL DEVELOPMENT and FUNCTION1 （TDF1） is a member of the R2R3 MYB family and is essential for early tapetum development in Arabidopsis. Here, we characterized an ortholog of Ara- bidopsis TDF1 in rice, OsTDF1 （LOC_Os03g18480）. OsTDF1 shares 69 % amino acid sequence identity with AtTDF1 in the putative MYB domain near the N-terminal region. RT-PCR and in situ hybridization show that OsTDF1 is specifically expressed in tapetal cells of rice anthers. The expression of OsTDF1 in Arabidopsis tdfl mutant restores its fertility, suggesting that this homolog can fulfill the normal function of TDF1 in Arabidopsis. The ostdfl knockout mutant exhibits a male-sterile phenotype. Its tapetal cells exhibit a vacuolated and hypertrophic phenotype similar to that of Arabidopsis tdfl mutants. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays revealed OsTDF1 acts as an essential regulator for tapetum programmed cell death. The qRT-PCR analysis revealed that OsTDF1 acts downstream of UDT1 and upstream of TDR, EAT1, OsMYBI03 and PTCI in rice, suggesting that the genetic pathway for tapetum development is generally conserved between rice and Arabidopsis,展开更多
文摘A novel tapetum-specific cDNA clone of rice, its corresponding gene designed as RA39, is isolated by RNA subtractive hybridization, differential screening and rapid amplification of cDNA ends. The RA39 cDNA is 1013 bp in length with an open reading frame encoding 298 amino acid residues. mRNA in situ hybridization reveals that RA39 is a tapetum-specific gene, and highly expressed at the meiosis stage of pollen mother cells. The deduced protein contains a signal peptide, a transmembrane region and a cytoplasmic tail, and is predicted to localize in endoplasmic reticulum by PSORT program. This cDNA sequence did not show significant homology to any known sequences in Genbank database. RA39 is the first gene identified to be expressed specifically in tapetal cells at the meiosis stage of pollen mother cells from cereals.
基金supported by the National Natural Science Foundation of China (30671127 and 30971553)the National Basic Research Program of China (2007CB947600)
文摘The Arabidopsis AtMYB103 gene is required for anther development,but whether the homologous gene in rice has the same role is unclear.Sequence analysis indicated that the rice OsMYB103 gene shares a high sequence similarity with AtMYB103.Therefore,we investigated the functional role of OsMYB103 in anther development using an RNAi approach.The OsMYB103 RNA transcript was expressed most abundantly in flowers,specifically in the tapetum,premeiotic pollen mother cells,and meiotic PMCs.OsMYB103-RNAi transgenic lines grew normally during their vegetative phase but displayed reduced male fertility,a phenotype that was associated with downregulated OsMYB103 transcript levels.Expression of OsMS2,an ortholog of the Arabidopsis AtMS2 gene,was also dramatically reduced in the transgenic plants.Knockdown of OsMYB103 led to defects in tapetum development,and most of the microspores in mature anthers lacked exines.Moreover,OsMYB103 could partially rescue the male sterility phenotype of an AtMYB103 knockout mutant ms188.Taken together,these results indicate that OsMYB103 does have an important role in rice tapetum and microspore development.
基金This work was supported by the grants from the Ministry of Science and Technology of China （2013CB945100）, the National Natural Science Foundation of China （31100227）.
文摘During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-MS1） for tapetal development and function. DEFECTIVE in TAPETAL DEVELOPMENT and FUNCTION1 （TDF1） is a member of the R2R3 MYB family and is essential for early tapetum development in Arabidopsis. Here, we characterized an ortholog of Ara- bidopsis TDF1 in rice, OsTDF1 （LOC_Os03g18480）. OsTDF1 shares 69 % amino acid sequence identity with AtTDF1 in the putative MYB domain near the N-terminal region. RT-PCR and in situ hybridization show that OsTDF1 is specifically expressed in tapetal cells of rice anthers. The expression of OsTDF1 in Arabidopsis tdfl mutant restores its fertility, suggesting that this homolog can fulfill the normal function of TDF1 in Arabidopsis. The ostdfl knockout mutant exhibits a male-sterile phenotype. Its tapetal cells exhibit a vacuolated and hypertrophic phenotype similar to that of Arabidopsis tdfl mutants. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays revealed OsTDF1 acts as an essential regulator for tapetum programmed cell death. The qRT-PCR analysis revealed that OsTDF1 acts downstream of UDT1 and upstream of TDR, EAT1, OsMYBI03 and PTCI in rice, suggesting that the genetic pathway for tapetum development is generally conserved between rice and Arabidopsis,
