| Stoma is a structure present in plant surface for gas and moisture exchanging with environment,which is surrounded by two guard cells.The stomatal development is tightly regulated by many factors,which can be used to study the developmental process of plants.Mature stomata of dicots are composed of two kidney-shaped guard cells,while stomata of monocot are composed of two subsidiary cells and two dumbbell-shaped guard cells to form a stomatal complex.The stoma structural differences of monocot and dicot may imply the different stomatal development process in monocot and dicot.Rice belongs to monocot and is an important crop.So far,the stomatal development and regulation of monocot is rarely understood.Therefore,it has important theoretical significance to study the stomatal development of rice and drawing the similarities and differences in stomatal development and regulation patterns between monocot and dicot and reveal the evolution of stoma.It also can provide theoretical guidance for agricultural production.In this study,main results were achieved by bioinformatic analysis,transgenic technology,transparent technology of plant leaves,differential interference contrast(DIC)microscope and chlorophyll fluorescence imaging technology in stomatal development-related mutants of rice.1.28 stomatal development-related genes of rice were bioinformatics analyzed,these genes can be categorized into five groups with different functions in stomatal development.Overexpression vectors of OsEPF ? OsCDKB1;1 ? OsYDA ? OsCRY2 ? OsCYCA2;1 and OsFLP were constructed and OsEPF::pCAMBIASP+1300,3 lines of OsCDKB1;1::pCAMBIASP+1300 and 3 lines of OsYDA::pCAMBIASP+1300 transgenic plants established.2.The stomata of wild-type seedlings of 20 d age were observed through transparent technology of plant leaves and differential interference microscope,and figures in each period of stomatal development of rice were got.3.It could be concluded that the loss of OsEPF?OsEPFL6?OsCRY1 genes may influence the development of stomata in rice through analysis of mutants osepf?osmkk7?osscrm?osepfl6?oscry1?ospan1?osmpk6?oscyca?osphya?osspch?oscycd4;2?osscd1?osfama,this result implies that these genes may regulate the stomatal development in rice.4.By contrasting wild type,osepf and OsEPF overexpression plants,it could be found that the stomatal density of wild type leaves was four times than that of OsEPF overexpression plants and the stomatal density of homozygous mutant is nearly twice than that of wild type.The seeds of OsEPF overexpression plants are smaller than that of wild-type and the photosynthetic efficiency of OsEPF overexpression plants was significantly lower than that of wild type.The carbon assimilation efficiency of OsEPF overexpression plants was 0.554,while the wild-type was 0.763.These results showed that OsEPF was involved in the stomatal development process of rice as the function of AtEPF in Arabidopsis,but the results need to be verified further.Based on the results above,it can be concluded that the stomatal development of rice and Arabidopsis is entirely different and rice exhibits more complex developmental process.Some homologous genes function at different stomatal development stages in rice and Arabidopsis may have the same function,for example,the mutants of OsEPF,OsEPFL6 and OsCRY1 exhibited an increasing trend in stomata density of rice leaves.But most mutants of homologous genes did not exhibited corresponding phenotypes probably because these genes were not involved in the process of stomatal development,or because there are many homologous of these genes in rice,so the deletion of one member of these genes die not lead to a corresponding phenotype because of the redundancy of gene functions.These issues need be examined in further study. |
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