Cloning And Functional Analysis Of The More Abundant Of CRY2 1(MAC1) Gene In Arabidopsis

CRYPTOCHROMEs(CRYs)are blue-light photoreceptors that are widely found in plants and animals to regulate various biological reactions.In plant,they participate in the blue light induced seedling morphogenesis,flower development,clock and circadian rhythm regulation and others psychological process.In model plant Arabidopsis,CRY1 act as photoreceptors mediating blue-light inhibition of hypocotyl elongationt,CRY2 act as long-day(LD)stimulation of floral initiation.To further study the regulators that influence CYR2 activities in Arabidopsis,through screening the CRY2-LUC transgene EMS mutagenesis pools of Arabidopsis,we found a mutantion within SUS2/PRP8 gene,this mutant was named mac1(more abundant of cry21).The main results of preliminary study on the phenotype of the mutant and the function of the MAC1,are as follows:1.EMS mutagenesis was used to screen CRY2 degradation inhibitors in Arabidopsis and obtained a mutant with early flower phenotype and increased CRY2 expression.This mutant was named mac1(more abundant of CRY2 1).Polymorphic molecular markers were used to find the mutation site of mac1.The mutant was identified as a base mutation in the sixth exon of the MAC1,and a guanine nucleotide(G)was mutated to adenine nucleotide(A).2.We created mac1 mutant by CRISPR/Cas9 system,we named it mac1-ct.Phenotypic observation of mac1-ctshowed that it has the same phenotype as wild type.The results indicate that the phenotype of the mac1 mutant is due to mutation in MAC1.3.The gene expression of CRY2 in mac1 was detected by Western Blot and q RT-PCR.It was found that MAC1 promoted CRY2 degradation at the post-transcriptional level.4.By counting the rosette leaves number of mac1 mutant we confirmed that mac1 exhibited an early flower phenotype under long-dayconditions.Measuring the hypocotyls length under different light conditions,mac1 showed shorter hypocotyls under blue light,red light and far-red light.The above results showed that MAC1 affected CRY2 gene expression at the protein level,it also regulates flowering time and hypocotyl length in Arabidopsis thaliana.This study provides new insight for further understanding the function of the MAC1 gene in light signal network.