Growth-regulating factors （GRFs） are plant-specific transcription factors that were originally identified for their roles in stem and leaf development, but recent studies highlight them to be similarly important for...Growth-regulating factors （GRFs） are plant-specific transcription factors that were originally identified for their roles in stem and leaf development, but recent studies highlight them to be similarly important for other central developmental processes including flower and seed formation, root development, and the coordination of growth processes under adverse environmental conditions. The expression of several GRFs is controlled by microRNA miR396, and the GRF-miRNA396 regulatory module appears to be central to several of these processes. In addition, transcription factors upstream of GRFs and miR396 have been discovered, and gradually downstream target genes of GRFs are being unraveled. Here, we review the current knowledge of the biological functions performed by GRFs and survey available molecular data to illustrate how they exert their roles at the cellular level.展开更多
Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMAD...Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.展开更多
The Asteraceae (Compositae),a large plant family of approximately 24 000-35 000 species,accounts for^10% of all angiosperm species and contributes a lot to plant diversity.The most representative members of the Astera...The Asteraceae (Compositae),a large plant family of approximately 24 000-35 000 species,accounts for^10% of all angiosperm species and contributes a lot to plant diversity.The most representative members of the Asteraceae are the economically important chrysanthemums (Chrysanthemum L.)that diversified through reticulate evolution.Biodiversity is typically created by multiple evolutionary mechanisms such as wholegenome duplication 0NGD)or polyploidization and locally repetitive genome expansion.However,the lack of genomic data from chrysanthemum species has prevented an in-depth analysis of the evolutionary mechanisms involved in their diversification.Here,we used Oxford Nanopore long-read technologyto sequence the diploid Chrysanthemum nankingense genome,which represents one of the progenitor genomes of domesticated chrysanthemums.Our analysis revealed that the evolution of the C.nankingense genome was driven by bursts of repetitive element expansion and WGD events including a recentWGD that distinguishes chrysanthemum from sunflower,which diverged from chrysanthemum approximately 38.8 million years ago.Variations of ornamental and medicinal traits in chrysanthemums are linked to the expansion of candidate gene families by duplication events including paralogous gene duplication.Collectively,our study of the assembled reference genome offers new knowledge and resources to dissect the history and pattern of evolution and diversification of chrysanthemum plants,and also to accelerate their breeding and improvement.展开更多
文摘Growth-regulating factors （GRFs） are plant-specific transcription factors that were originally identified for their roles in stem and leaf development, but recent studies highlight them to be similarly important for other central developmental processes including flower and seed formation, root development, and the coordination of growth processes under adverse environmental conditions. The expression of several GRFs is controlled by microRNA miR396, and the GRF-miRNA396 regulatory module appears to be central to several of these processes. In addition, transcription factors upstream of GRFs and miR396 have been discovered, and gradually downstream target genes of GRFs are being unraveled. Here, we review the current knowledge of the biological functions performed by GRFs and survey available molecular data to illustrate how they exert their roles at the cellular level.
基金We gratefully acknowledge B Han from National Center for Gene Research, Chinese Academy of Sciences (CAS) and Rice Genome Resource Center (RGRC) for providing BAC clone, cDNA clone and Tosl7 insertion line. We thank Z-J Luo and M-J Chen from Shanghai Jiao Tong University for mutant screening and generation of F2 populations, X-Y Gao from Institute of Plant Physiology and Ecology, SIBS, CAS, for SEM, H Yu from Nation- al University Of Singapore for critical reading of this manuscript and H Ma from Fudan University for helpful discussion. This work was supported by funds from the National Basic Research Program of China (2009CB941500, 2006CB 101700), the National Natural Science Foundation of China (30725022, 30830014 and 90717109) and the Shanghai Leading Academic Discipline Project (B205).
文摘Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.
基金The National Key Research and Development Program of China (2016YFD0801102)and the National Natural Science Foundation of China (31870198 and 31400278).
文摘The Asteraceae (Compositae),a large plant family of approximately 24 000-35 000 species,accounts for^10% of all angiosperm species and contributes a lot to plant diversity.The most representative members of the Asteraceae are the economically important chrysanthemums (Chrysanthemum L.)that diversified through reticulate evolution.Biodiversity is typically created by multiple evolutionary mechanisms such as wholegenome duplication 0NGD)or polyploidization and locally repetitive genome expansion.However,the lack of genomic data from chrysanthemum species has prevented an in-depth analysis of the evolutionary mechanisms involved in their diversification.Here,we used Oxford Nanopore long-read technologyto sequence the diploid Chrysanthemum nankingense genome,which represents one of the progenitor genomes of domesticated chrysanthemums.Our analysis revealed that the evolution of the C.nankingense genome was driven by bursts of repetitive element expansion and WGD events including a recentWGD that distinguishes chrysanthemum from sunflower,which diverged from chrysanthemum approximately 38.8 million years ago.Variations of ornamental and medicinal traits in chrysanthemums are linked to the expansion of candidate gene families by duplication events including paralogous gene duplication.Collectively,our study of the assembled reference genome offers new knowledge and resources to dissect the history and pattern of evolution and diversification of chrysanthemum plants,and also to accelerate their breeding and improvement.
