Comparative studies on phytolith morphology between wild rice(Oryza rufipogon)and domesticated rice(Oryza sativa)have provided a fundamental basis for examining rice domestication traits and their evolutionary pathway...Comparative studies on phytolith morphology between wild rice(Oryza rufipogon)and domesticated rice(Oryza sativa)have provided a fundamental basis for examining rice domestication traits and their evolutionary pathways.To investigate the taxonomic significance of modern rice phytoliths,this study conducted systematic morphometric and statistical evaluations on cuneiform bulliform,double-peaked husk,and bilobate phytoliths of wild rice and two domesticated rice subspecies,japonica(O.sativa subsp.japonica'Ganningjing No.1')and indica(O.sativa subsp.indica'CNR213'),cultivated in Wuhan experimental fields.The findings revealed the following:(1)The number of fish-scale facets on cuneiform bulliform phytoliths and the morphology of double-peaked husk and bilobate phytoliths effectively differentiated wild rice from domesticated rice at the species level.Specifically,the cuneiform bulliform phytoliths with≥9 fish-scale facets were 6%,40%,and67%for wild,japonica,and indica rice,respectively.The shank length(a)and notch width(b)of bilobate phytoliths,as well as the top width(TW),middle width(MW),height(H),and curve depth(CD)of double-peaked husk phytoliths in domesticated rice,were smaller than those in wild rice.The morphometric features of the bilobate phytoliths demonstrate their potential as novel indicators for distinguishing wild rice from domesticated rice.(2)At the subspecies level,morphological variations were observed in the phytoliths of japonica and indica rice.Specifically,the flat ratio(B/A,where B and A are the non-base portion length and base portion length of cuneiform bulliform phytoliths,respectively)and fish-scale facet number of cuneiform bulliform phytoliths in japonica rice were lower than those in indica rice,but the horizontal(HL)and vertical length(VL)of japonica rice were greater than those of indica rice.This study provides phytolith-based evidence for the classification and identification of modern rice and offers valuable insights for identifying rice phytolith traits from archaeological sites and for understanding the domestication and evolutionary pathways of rice.Considering the limited variety of rice types included in this study,future research should investigate more rice species to create a comprehensive morphometric classification system for phytolith analyses.展开更多
The significant variation in plant regeneration efficiency between indica and japonica rice poses a major challenge for crop improvement.However,the molecular basis for this divergence remains largely unclear.In this ...The significant variation in plant regeneration efficiency between indica and japonica rice poses a major challenge for crop improvement.However,the molecular basis for this divergence remains largely unclear.In this study,we investigated the role of Oryza sativa AUXIN RESPONSE FACTOR 13(OsARF13),a transcription factor involved in callus-related processes.We observed that OsARF13 expression is significantly higher in japonica rice callus than in indica rice callus.This differential expression might be associated with an allelic variation in the promoter region of OsARF13,where a deletion commonly found in indica rice corresponds to the loss of a conserved auxin-responsive element(AuxRE)motif.To functionally characterize OsARF13,we generated CRISPR/Cas9-mediated knockout mutants.These mutants exhibited a substantial reduction in callus fresh weight,demonstrating that OsARF13 is required for efficient callus induction.Transcriptome analysis of the osarf13 mutant further showed that OsARF13 influences the expression of genes involved in hormone signal transduction and stress responses.Our findings suggest that OsARF13 is a key component of the regulatory network governing callus induction and that natural variation in its promoter might provide a potential explanation for the differential regenerative capacity between japonica and indica rice subspecies.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.U23A2023,42077408)。
文摘Comparative studies on phytolith morphology between wild rice(Oryza rufipogon)and domesticated rice(Oryza sativa)have provided a fundamental basis for examining rice domestication traits and their evolutionary pathways.To investigate the taxonomic significance of modern rice phytoliths,this study conducted systematic morphometric and statistical evaluations on cuneiform bulliform,double-peaked husk,and bilobate phytoliths of wild rice and two domesticated rice subspecies,japonica(O.sativa subsp.japonica'Ganningjing No.1')and indica(O.sativa subsp.indica'CNR213'),cultivated in Wuhan experimental fields.The findings revealed the following:(1)The number of fish-scale facets on cuneiform bulliform phytoliths and the morphology of double-peaked husk and bilobate phytoliths effectively differentiated wild rice from domesticated rice at the species level.Specifically,the cuneiform bulliform phytoliths with≥9 fish-scale facets were 6%,40%,and67%for wild,japonica,and indica rice,respectively.The shank length(a)and notch width(b)of bilobate phytoliths,as well as the top width(TW),middle width(MW),height(H),and curve depth(CD)of double-peaked husk phytoliths in domesticated rice,were smaller than those in wild rice.The morphometric features of the bilobate phytoliths demonstrate their potential as novel indicators for distinguishing wild rice from domesticated rice.(2)At the subspecies level,morphological variations were observed in the phytoliths of japonica and indica rice.Specifically,the flat ratio(B/A,where B and A are the non-base portion length and base portion length of cuneiform bulliform phytoliths,respectively)and fish-scale facet number of cuneiform bulliform phytoliths in japonica rice were lower than those in indica rice,but the horizontal(HL)and vertical length(VL)of japonica rice were greater than those of indica rice.This study provides phytolith-based evidence for the classification and identification of modern rice and offers valuable insights for identifying rice phytolith traits from archaeological sites and for understanding the domestication and evolutionary pathways of rice.Considering the limited variety of rice types included in this study,future research should investigate more rice species to create a comprehensive morphometric classification system for phytolith analyses.
基金supported by the National Natural Science Foundation of China(Grant Nos.32201834 and 32201814)the Hainan Provincial Natural Science Foundation of China(Grant No.324RC530)+1 种基金the Hainan Provincial‘Nanhai NewStar’Science and Technology Innovation Platform Project,China(Grant No.NHXXRCXM-202362)the Research Startup Funding from Hainan Institute of Zhejiang University,China(Grant No.0201-6602-A12202).
文摘The significant variation in plant regeneration efficiency between indica and japonica rice poses a major challenge for crop improvement.However,the molecular basis for this divergence remains largely unclear.In this study,we investigated the role of Oryza sativa AUXIN RESPONSE FACTOR 13(OsARF13),a transcription factor involved in callus-related processes.We observed that OsARF13 expression is significantly higher in japonica rice callus than in indica rice callus.This differential expression might be associated with an allelic variation in the promoter region of OsARF13,where a deletion commonly found in indica rice corresponds to the loss of a conserved auxin-responsive element(AuxRE)motif.To functionally characterize OsARF13,we generated CRISPR/Cas9-mediated knockout mutants.These mutants exhibited a substantial reduction in callus fresh weight,demonstrating that OsARF13 is required for efficient callus induction.Transcriptome analysis of the osarf13 mutant further showed that OsARF13 influences the expression of genes involved in hormone signal transduction and stress responses.Our findings suggest that OsARF13 is a key component of the regulatory network governing callus induction and that natural variation in its promoter might provide a potential explanation for the differential regenerative capacity between japonica and indica rice subspecies.
