Preliminary Study On Anthers Of Oryza Longistaminata

With the rapid increase of the global population,the importance of food to mankind has become more and more obvious.As one of the important food crops,how to increase the yield of rice has always been a concern of breeders.The development of floral organs directly affects the final yield of crops,so the research on floral tubes is very important.The Oryza longistaminata has the same genome(AA)as the Asian cultivated rice,long anthers,and large pollen,so it is regarded as an ideal donor for the transfer of these excellent traits.In this study,O.longum sativum was used as the research material.Through the observation of cell morphology and the study of physiological indicators of anthers,the cytological basis of stamen development of O.longum was excavated.Transcriptome analysis is used to explore the differential epigenes in the anther development process,and to further understand the development mechanism of long-male wild rice anthers.The main results are as follows:1.By measuring the length of the anthers of Oryza longistaminata and 9311,the results show that the length of the anthers of Oryza longistaminata is longer than that of 9311.Experiments such as iodine staining,in vitro pollen culture,and pollen germination on the stigma showed that there was no significant difference between the fertile pollen of Oryza longistaminata and the 9311 fertile pollen.Scanning and observation of Oryza longistaminata and 9311 mature pollen grains,it is concluded that the pollen grains of Oryza longistaminata is non-porous and the pollen surface is rough.Observed by semi-thin sections at each stage of the anther development of Oryza longistaminata,the results showed that the number of microspore mother cells was large,and more microspores were produced.During the bicellular pollen period,the adjacent anther wall opens to prepare for the release of pollen grains.Partially aborted anthers were found in the anthers of Oryza longistaminata,which occurred during the meiosis preparation period.The cause of abortion is the serious degree of fibrosis of the anther wall and the inability of normal meiosis in microspore mother cells.2.The soluble sugar content during the anther development of Oryza longistaminata reaches its maximum during meiosis and then gradually decreases.The changes in antioxidant enzyme activity generally show a downward trend,and peroxidase peaks during preparations for meiosis.3.In order to explore the mechanism of the development of anthers in Oryza longistaminata,transcriptomics analysis of the anther secondary cell stage,meiosis preparation stage,bicellular pollen stage,and mature pollen grain stage were carried out,and enriched through the KEGG and GO pathways.Analysis revealed 5 unknown genes.They play a role in the synthesis of arginine,the synthesis of brassinolide and the synthesis of light and pigment,respectively.4.The total protein analysis of the four developmental stages of Oryza longistaminata anthers showed that there were differences in the total protein of the four stages,and the difference between the meiotic stage and the bicellular pollen stage was more obvious.5.Perform in vitro knockout verification for 5 unknown candidate genes,of which 2candidate genes were successfully knocked out in vitro,and construct a CRISPR-Cas9 knockout vector based on these 2 candidate genes.