Analysis Of Small RNA Expression Profiles Related To Vernalization And Study On The Mechanism Of Light Promoting Vernalization In Wheat

Vernalization refers to the phenomenon that plants must undergo a period of sustained low temperature to transfer from vegetative growth stage to reproductive stage,Winter wheat has obvious vernalization characteristics.In order to study the molecular mechanism of winter wheat vernalization,on the one hand,high-throughput sequencing of small RNA was used to detect the expression pattern of miRNA in leaves before vernalization,vernalization at 2 weeks,4 weeks and 6 weeks,Identify known miRNAs and new miRNAs in wheat and screen for wheat miRNAs associated with vernalization.The results are as follows:(1)Based on the small RNA expression profiles of wheat leaves in four periods,2393 known miRNAs and 850 new non-redundant miRNAs were identified.(2)Compared with pre-vernalization,the up-regulated miRNAs in the known miRNAs were 11 at 2 weeks of vernalization,15 at 4 weeks,13 at 6 weeks,and up-regulated at three time points.One.The down-regulated expression of miRNA was 5 at 2 weeks of vernalization,8 at 4 weeks,12 at 6 weeks,and 13 at three time points.(3)Compared with pre-Vernalization,among the 850 new miRNAs,the up-regulated miRNAs were 31 at 2 weeks of vernalization,53 at 4 weeks,and 39 at 6 weeks,at three time points.The number of upward adjustments is 21.The number of miRNAs down-regulated was 56 at 2 weeks of vernalization,58 at 4 weeks,57 at 6 weeks,and 42 at three time points.The above results laid the foundation for the study of the mechanism of miRNA in wheat.On the other hand,in order to study the effects of illumination on vernalization during the vernalization stage,dark vernalization(D)and long-light vernalization(LD)treatment were carried out,respectively,and then two treatments were applied to wheat heading time,plant height and The influence of the number of leaves and the expression patterns of vernalization,photoperiod,circadian clock and methylation-related genes under two vernalization conditions were detected.The results are as follows:(1)Under the condition of long-light vernalization,the heading time of wheat is 16 days earlier than that under dark vernalization,and the long-lighting on the phenotypic leaves is 1-3 more than that under dark vernalization.The plant height is long-lighted vernalized wheat.Wheat is 3-5 cm higher than dark vernalization.(2)The expression of vernalization gene VRN1 under long-light vernalization was higher than that under dark vernalization.VRN2 was hardly expressed during vernalization,while the expression of TaODDSOC2 was higher than that of long-light vernalization under dark vernalization.(3)The expression of photoperiod-related genes was significantly increased during the long-light vernalization than during the dark vernalization.(4)The genes related to the circadian clock and the methylation-related genes were expressed under long-light vernalization conditions under dark vernalization conditions.The above results provide a basis for the study of photoperiod regulation of wheat vernalization.