Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being...Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being the innermost layer,plays a critical role in supplying nutrients,enzymes,and protection to microspores.Detailed microscopic and ultrastructural analyses have revealed highly active and well-organized structures within the tapetum,referred to as tapetal organelles.Molecular studies have highlighted the significance of tapetal cell death and the nurturing role of the tapetum for microspores.However,the mechanisms by which these processes are mediated by tapetal organelles at the cellular level remain elusive.The discovery of mutants defective in tapetal organelles has enabled further investigations into their structure,morphology,and function.This review discusses the molecular and functional roles of various tapetal organelles,such as plastids(amyloplasts and elaioplasts),mitochondria,tapetosomes,endoplasmic reticulum,and lipid bodies.We provide an overview of their roles,highlight key organelles in the tapetum,and address recent challenges and potential applications of genes regulating tapetal organelles in enhancing crop fertility.展开更多
Ribosome-like particles have been found in the proplastids in young cotyledon cells of lotus (%Nelumbo nucifera Gaertn% L.). Following the development of young embryo, some lamellar structures and tubular complex occu...Ribosome-like particles have been found in the proplastids in young cotyledon cells of lotus (%Nelumbo nucifera Gaertn% L.). Following the development of young embryo, some lamellar structures and tubular complex occurred in the plastids in young cotyledon cells, and some ribosome-like particles appeared in the loose region of these membrane system and stroma. About 15- 20 d after fertilization, with the further development of plastid, a large number of starch and DNA were synthesized in the plastids, and the plastids contained abundant and clear morphologically ribosomes, some of which presented spiral structure. About 16-18 d after fertilization, amyloplasts were isolated and purified from cotyledon of lotus, and ribosomes bands were obtained by use of sucrose density gradient centrifugation of ribosomes isolated from amyloplasts. RNA and protein contents of ribosomes have also been determined.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32272191 and 32350410428).
文摘Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being the innermost layer,plays a critical role in supplying nutrients,enzymes,and protection to microspores.Detailed microscopic and ultrastructural analyses have revealed highly active and well-organized structures within the tapetum,referred to as tapetal organelles.Molecular studies have highlighted the significance of tapetal cell death and the nurturing role of the tapetum for microspores.However,the mechanisms by which these processes are mediated by tapetal organelles at the cellular level remain elusive.The discovery of mutants defective in tapetal organelles has enabled further investigations into their structure,morphology,and function.This review discusses the molecular and functional roles of various tapetal organelles,such as plastids(amyloplasts and elaioplasts),mitochondria,tapetosomes,endoplasmic reticulum,and lipid bodies.We provide an overview of their roles,highlight key organelles in the tapetum,and address recent challenges and potential applications of genes regulating tapetal organelles in enhancing crop fertility.
文摘Ribosome-like particles have been found in the proplastids in young cotyledon cells of lotus (%Nelumbo nucifera Gaertn% L.). Following the development of young embryo, some lamellar structures and tubular complex occurred in the plastids in young cotyledon cells, and some ribosome-like particles appeared in the loose region of these membrane system and stroma. About 15- 20 d after fertilization, with the further development of plastid, a large number of starch and DNA were synthesized in the plastids, and the plastids contained abundant and clear morphologically ribosomes, some of which presented spiral structure. About 16-18 d after fertilization, amyloplasts were isolated and purified from cotyledon of lotus, and ribosomes bands were obtained by use of sucrose density gradient centrifugation of ribosomes isolated from amyloplasts. RNA and protein contents of ribosomes have also been determined.
