Cloning And Functional Analysis Of Flowering Gene CONSTANS-LIKE1 And CONSTANS-LIKE13 Of Soybean

The study on the model plant Arabidopsis reveals that flowering is regulated through at least five pathways: vernalization pathway,photoperiod pathway,gibberellin pathway,autonomous pathway and aging pathway.CONSTANS(CO)plays a crucial role in the photoperiod pathway.However,the molecular mechanism of CO homologous gene regulation in flowering in soybean is rarely reported.A total of 23 homologous genes of CO(GmCOL,Glycine max CO-Like)were cloned from soybean Kennong 18.The results show that four GmCOL genes have high similar ity to Arabidopsis thaliana,GmCOL1,2,5,and 13.And overexpression of GmCOL5 enhances Arabidopsis mutant co-2 flowering.Therefore,GmCOL1,2,5,and 13 were good candidates of CO homologs in soybean.So,they were selected for further study here.This paper attempts to further study the function of GmCOL1 and GmCOL13 in soybean flowering regulation.The results are as follows:1.Bioinformatics analysis shows that the promoter of both GmCOL1 and GmCOL13 contains the following important elements : circadian elements,cis-acting regulatory elements involved in light response,cis-acting elements involved in ABA response,MYB binding sites involved in drought-inducibility,and cis-acting elements involved in low-temperature response.And GmCOL13 also contains GA response elements.Indicating that the regulation of GmCOL1 and GmCOL13 are likely to be affected by photoperiod,drought and low temperature.2.GUS staining was performed with GmCOL1 and GmCOL13 transgenic plants.It was found that GmCOL1 and GmCOL13 promoter had similar GUS activity under long and short day conditions,indicating that GmCOL1 and GmCOL13 may not be affected by the length of the day;In the far red light conditions,the promoter activity of GmCOL1 and GmCOL13 decreased,indicating that the transcription level may be inhibited by far red light;under the conditions of NaCl and PEG stress,the promoter activity of GmCOL1 and GmCOL13 decreased,indicating that it may be involved in stress response.3.We got Enhancer:GmCOL13pro::genomicGmCOL13:FLAG transgenic soybean plants through soybean cotyledon transformation method.It was found that there was no significantly difference in flowering time with wild type under short day conditions,however,the transcription level of GmCOL13 in transgenic plants decreased.Under long day conditions,the transcription level of GmCOL13 in transgenic plants was decreased,but the expression of the GmCOL13 in the long day is higher than that in the short day,indicating that it can react to the day length.4.When Enhancer:GmCOL13pro::genomicGmCOL13:FLAG transgenic soybean plants were grown under far-red light conditions,GmCOL13 expression was decreased,indicating that far-red light may be involved in the regulation of GmCOL13 expression.5.Under drought conditions plants of Enhancer:GmCOL13pro::genomic GmCOL13 :FLAG,GmCOL13 expression was also decreased,indicating that GmCOL13 may be involved in stress regulation.