Interaction Analysis Between Photoperiod Sensitive Gene ZmCCT And Stress Responsive Genes

Maize(Zea mays L.)is known as “The first of grains and fodder”,as well as the first planting area in food crops.However,as the short-day plant,photoperiodism under temperature zone severely prevented the germplasm utilize of the tropical and subtropical zone in maize because of abnormal flowering.Therefore,it is important to study the molecular mechanism of photoperiod.This study is significant for tropical and sub-tropical region be planting in temperate zone,which the relationship between the photoperiod sensitive genes and tress tolerance.In this study,we used the photoperiod insensitive inbred line Huangzao 4(H4)and its nearly isogenic sensitive inbred line H496 as the material,and performed RNA-seq technology for transcriptome analysis,and through the photoperiod sensitivity and high temperature of the two materials.Identification of stress resistance of drought and pathogenic bacteria.Trying to analyze the relationship between photoperiod and bio-or abiotic stress response in maize.The main conclusions were as follows:1.Through the phenotype identification of H4 and H496,show that the phenotypes of the two materials were significantly different in long-day sunlight.H496 were significantly higher than H4.The pollen day of H4 is 5 days earlier than H496 and 9 days earlier at the silking stage.But the two materials were found different in the short days.The result indicates that H496 show obvious photoperiod sensitivity.The plants of H4 and H496 were treated by drought and high,temperature and biotic stress(Fusarium graminearum).The result showed that H496 performed more obvious resistance than H4.It is demonstrated that Zm CCT with photoperiod-sensitive gene are also involved in resistance to both biological and abiotic stresses.2.DNA library from the Shoot apical meristem of H4 and H496 was successfully performed.By analyzing the transcriptome differences between the two materials under long day,we obtained 507,648,669 and 737 differentially expressed genes(DEGs),respectively.Also found leaf three development-phase(3-leaf stage),transform-phase(4-and 5-leaf stage)and reproductive-phase(the 6-leaf stage)were obtained 1,218,790 and 1,596 specifically expressed genes in H4,respectively.H496 had 1,784,950,and 1,248 in the three stages of nutrition(3-leaf stage),transformation(5-and 6-leaf stage),and reproductive(7-leaf stage),respectively.3.STEM was used to identify the expression pattern of DEGs.The results showed that expression pattern of H4 and H496 are significantly different.but 42.42%(profile 36,37,25 and 23)and 6.9%(6,22,3,and 2)of DEGs were identified during transition phase change.Agri GO analysis indicate DEGs of H4 and H496 can be attributed to biological processes,cell components,and molecular functions.The biological processes are significantly enriched in biological regulation,cellular processes,metabolic processes,and stimuli response,and cellular components are enriched in organelles,etc.,Molecular functions enriched in catalytic activity.4.To establish a biologically developed GO function and KEGG pathway network using DEGs at four development stages.The pathway content 41 GO and KEGG terms,67 gene nodes and 422 edges.The KEGG network mainly includes mechanical damage response,body temperature balance,photosynthetic system,metabolic process,and ion transport.Genes such as GRMZM2G177412,GRMZM2G352132,and LOC100281861 play roles in two or more related pathways.5.A co-expression network was established using 92 differentially expressed genes with high correlation.The number of genes related to photoperiod,biotic stress,and abiotic stress was 39,13,and 40,respectively.GRMZM2G024668,GRMZM2G134668,GRMZM2G022180,and GRMZM2G175265 participated in two regulation pathways.While GRMZM2G091481 and GRMZM2G389173 participated in the regulation of three pathways.Promoter element analysis evidenced that 62.5% of stress related genes promoters contained multiple biological clocks and light response elements.These results further indicate that the photoperiod response genes may be involved in biological and abiotic stress responses,and the important function of Zm CCT is indicated as connection node between circadian and stress response.