Fine Mapping Of Seed Storability QTL And The Effects Of Aleurone Layers Metabolites On Seed Storability In Rice

Seed storability is an important agronomic trait which is determined by many factors such as genetics,developmental environment and storage conditions.Storage under adverse environmental conditions can easily cause deterioration of seed quality and decrease in seed vigor.Rice seed aleurone layer is rich in protein,fatty acids,phenolic acids,polyphenols,vitamins and flavonoids,which may affect the storability of seeds.In this experiment,the NIP/ZS97 chromosomal segment substitution lines(CSSL)was used for artificial agi ng phenotype and five near isogenic lines were selected for fine mapping of storability QTLs,measurement of storage compounds,metabolomics of different components of the seed,transcriptomics of aleurone layer.Mature seed aleurone layer structure was also analyzed and compared to the background line ZS97.The main findings are as follows:1.Using the NIP/ZS97 population,17 QTLs of artificial aging phenotypes Gmax and AUC were co-localized.Five near-isogenic lines were selected for effect validation and two storable QTLs qSLnz1.1 and qSLnz1.2 were find-mapped.qSL1.1 is located between38.414 Mbp and 38.517 Mbp on the first chromosome which is 102.3kb while qSL1.2 is located at the end of the first chromosome between 39.823 Mbp and 39.951 Mbp which is127 kb.2.800 intact rice seeds were manually removed embryo and placed in JMNJ-3 small rice mill for 15 s.The seed aleurone layer could be quickly and successfully separated from the endosperm and can be collected easily for further analysis.3.After 8 days of artificial aging,the total antioxidant content in the seeds of the five near-isogenic lines was significantly decreased compared with ZS97.The content of total fatty acids in the embryo and endosperm of five near-isogenic seeds were increased after artificial aging,while the total fatty acids of NZ228 in the aleurone layer were decreased,indicating the qSLnz11.1 or qSLnz11.2 may be specifically function in the aleurone layer,and the storability of the seed is regulated by controlling the fatty acid content.The respiration rate of the seed were increased after artificial aging for 6 days.4.The metabolome and transcriptome of the rice seed aleurone layer were analyzed.The integrated analysis demonstrated that the peroxidase gene OsZS＿04G0498300 in the NZ127 introduced fragment may regulate the storability of seeds through the change of caffeic acid content,While the acyltransferase gene OsZS＿01G0676000 in the NZ24 and NZ29 introduced fragment may affect the storability of seeds by regulating the metabolism of sn-Glycero-3-phosphocholine and Choline in the seed aleurone layers.