Study On OsGRPs Positive Regulation Of Rice Storage Tolerance

Rice is the main food crop in China and plays an extremely important role in food security.Due to the seasonality of rice production and the continuity of rice consumption,the vast majority of rice undergoes a storage process after harvest.With the prolongation of rice storage time,some nutritional components of rice inevitably undergo physiological and chemical changes,leading to deterioration in the taste quality of rice and a decline in its commerciality.In order to slow down the deterioration of rice quality during storage,physical and chemical methods such as lowering storage temperature,changing rice storage packaging,etc.are often used to improve the quality of rice storage,but significantly increasing the cost of rice storage.Therefore,how to mitigate the deterioration of taste quality of rice after storage from a genetic perspective is a key issue in the production and consumption process of rice.Glycine-rich RNA-binding proteins(GRPs)are widely present in many higher plants(such as carrots,corn,wheat,Arabidopsis,rice,etc.).Currently,members of the OsGRPs family have been reported to be mainly involved in the growth and development,seed setting rate,stress resistance,and other traits of higher plants,but their role in the storage resistance of rice is unclear.In this study,the discovery of AtGRP7 regulating seed vigor in Arabidopsis was used as a starting point to identify two corresponding homologous genes OsGRP1A and OsGRP3 in rice.A series of research results showed that OsGRPs affected rice quality and storage tolerance.The regulatory mechanism was preliminarily explored through transcriptome analysis and protein interaction experiments.The main research results are as follows:Identification of OsGRPs homologous genes in rice.The previous research team found that AtGRP7 in Arabidopsis regulates seed vigor.Using this as a starting point,in order to explore whether there are homologous genes in the OsGRPs protein family of rice involved in the regulation of rice seed vigor or quality,we found two corresponding homologous genes OsGRP1A and OsGRP3 in rice by comparing the GRP protein sequences of Arabidopsis and rice.OsGRPs regulate rice quality and storage resistance.We measured the starch related indicators of aged rice,and the results showed that there were significant differences in total starch content and total starch consumption rate between wild type(Nip)and overexpressed OsGRPs.The main performance is that the total starch consumption rate of artificially aged OsGRP1A-OE-1,OsGRP1A-OE-5,and OsGRP3OE is significantly lower than that of Nip;The above results indicate that OsGRPs can delay starch consumption during rice storage.At the same time,we also measured the germination rate,TTC staining,germination potential,and other indicators of rice during different storage periods,and found that OsGRPs also affect the storage resistance and cell viability of rice.In summary,OsGRPs genes can affect rice quality and storage resistance.Preliminary study on the mechanism of OsGRP3 regulating storage resistance.Firstly,by analyzing the transcriptome data of artificially aged OsGRP3-OE,it was found that compared to the differential genes before and after aging of Nip,the changes in the differential genes before and after aging of OsGRP3-OE were more gradual,suggesting that OsGRP3 has the function of alleviating the gene expression level after aging.GO enrichment analysis showed that compared with Nip,OsGRP3-OE expressed differently in fatty acid metabolism and transcriptional regulation.This finding suggests that OsGRP3 may be involved in processes such as metabolic response and fatty acid metabolism during seed storage.In addition,KEGG is enriched in starch metabolism related pathways.Compared with Nip,the transcriptional abundances of OsRAG2 and OsPUL genes related to starch metabolism were significantly downregulated before and after aging of OsGRP3-OE,suggesting that OsGRP3 may delay the deterioration of rice quality during storage by inhibiting the expression of genes related to starch metabolism.Preliminary study on the signal pathway of OsGRP3 controlling rice quality and storage tolerance..In order to further explore the mechanism by which OsGRP3 regulates storage tolerance,the transcription factor OsZHD1 was analyzed through evolutionary tree analysis,and it was demonstrated by means of fluorescein enzyme complementation and GST pull-down experiments that OsGRP3 can interact with OsZHD1.Through protein structure prediction,it was found that OsZHD1 has an unstable region at 168-190AA,and these two transcriptional forms were named OsZHD1.1 and OsZHD1.2.Through detailed interaction,it was found that this unstable region is an important factor affecting the interaction between OsGRPs and OsZHD1,Due to the fact that the main environmental factor causing deterioration during rice storage is high temperature,OsZHD1 was found to actively regulate the transcription ratios of OsZHD1.1 and OsZHD1.2 under high temperature conditions after induction.The main performance is that under high temperature conditions,the transcription ratio of OsZHD1.1 containing unstable regions increases significantly,resulting in a significant increase in the ability to interact with OsGRPs.Therefore,this study preliminarily indicates that OsZHD1 regulates the interaction with OsGRPs by dynamically adjusting the transcription ratios of OsZHD1.land OsZHD1.2 transcriptional forms in response to the temperature of the storage environment.Moreover,OsGRPs may delay the quality deterioration of rice during storage by regulating genes related to starch metabolism during rice storage.