The embryo surrounding cells may be involved in communicating and transferring of nutrients between endosperm and embryo. The transfer cells transport nutrient solutes from maternal tissues to the endosperm, while the starchy endosperm and aleurone layer are packed with starch granules, storage proteins and minerals. The endosperm cells, then, undergo mitosis and differentiated into four major specialized tissues: the transfer cells, aleurone layer, starchy endosperm, and embryo surrounding cells. Like other angiosperms, maize endosperm is formed through the process of double fertilization, but undergoes the nuclear form of endosperm development (ESD), in which the primary endosperm nucleus divides repeatedly without cell wall formation. Cereal endosperm has received a lot of deliberate research attentions owing to its significance in agriculture. In contrast to dicots such as Arabidopsis thaliana, which have a transitory endosperm, maize ( Zea mays L.) and other cereals have persistent endosperm in their mature seeds. The cereal endosperm, a storage tissue, serves as important source of nutrients for humans and animals, and industrial raw materials. Thus, the EPS will benefit the research of cereal grain yield and quality improvement. Such analyses will be invaluable in characterizing endosperm-trait related genes whose functions have not been identified. The development of the optimized protoplast isolation and transfection conditions, allow the exploitation of the functional advantages of protoplast system over biolistic system in conducting endosperm-based studies (particularly, in transient analysis of genes and gene regulation networks, associated with the accumulation of endosperm storage products). The described optimized conditions proved efficient for reasonable yield of viable protoplasts from maize endosperm, and utility of the protoplast in rapid analysis of endosperm-trait related genes. The EPS was used to express GFP protein, analyze the subcellular location of ZmBT1, characterize the interaction of O2 and PBF1 by bimolecular fluorescent complementation (BiFC), and simultaneously analyze the regulation of ZmBt1 expression by ZmMYB14. The optimized conditions of 1% cellulase, 0.75% macerozyme and 0.4 M mannitol enzymolysis solution for 6 h showed that more than 80% protoplasts remained viable after re-suspension in 1 ml MMG. By using response surface designs, we established optimized conditions for the isolation and PEG-calcium mediated transfection of maize endosperm protoplasts. Here, we showed the uniqueness of maize endosperm-protoplast system (EPS) in conducting endosperm cell-based experiments. Prior to this study, no PEG-calcium mediated endosperm protoplast system has been reported for cereal crop, perhaps, because endosperm cells accumulate starch grains. Notably, starch granules in cereal endosperm may diminish protoplast yield and integrity, if the isolation and transfection conditions are not accurately measured. Typically, PEG-calcium mediated transfection of protoplast is simple and cost-effective. Plant protoplasts are efficient cell-based systems which allow quick and simultaneous transient analysis of multiple genes. Moreover, the biolistic system has little physiological relevance when compared to cell-specific based system. Besides, it cannot be used for simultaneous analysis of multiple genes. The biolistic system, which is often used for transient gene expression, is expensive and involves complex protocol. There are vast numbers of these genes whose functions and regulations are still unknown. Endosperm-trait related genes are associated with grain yield or quality in maize.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |