| Light is essential for the survival of Photoautotrophs and also functions as a crucial environmental signal.During the course of evolution,marine brown algae have developed the ability to monitor light in their surroundings and adjust their developmental patterns in order to optimize their photosynthesis and light utilization.Analysis of the core components of light sensing and light signaling in marine algae is still lacking.Two photoreceptor proteins Aureochrome(AUREO)and Cryptochrome/Photolyase Family(CPF)in S.japonica mainly responding to blue light were preliminarily studied using gene family analysis,transcription factor-centered yeast one-hybrid(TF centered Y1H)and protein prokaryotic expression technology explore.The research results are as follows:1.In this study,44 AUREO genes were identified and collected from the genomes of seven algae,and then the AUREO phylogenetic tree was constructed and divided into five subgroups.A large number of different cis-acting elements were identified upstream of the AUREO genes in brown algae,the largest number of which were related to the light response.The S.japonica developmental transcriptome data showed that the expression of Sj AUREO was significantly different in different developmental stages of S.japonica gametophytes.Further through light-induced periodic rhythm experiments,it was found that the expression of Sj AUREO showed a light-dependent circadian cycle change expression pattern,which was different from other similar studies in the past.These indicated that blue light may transmit light signal through AUREO and affect the development of gametocytes.In order to further study the relationship between Sj AUREO and gametophyte development,the prokaryotic expression system of Sj AUREO1 c was constructed,and the Sj AUREO1 c protein was purified;in addition,through TF centered Y1 H experiments,multiple potential interaction elements of Sj AUREO1 c were obtained,including Temperature,light,rhythm,cell division,and other cis-elements,as well as some potential interaction elements that have not been described.This indicates that Sj AUREO1 c may participate in a wide range of biological processes in photomorphogenesis.2.The other part of this study focuses on the CPF members in the economic brown alga S.japonica,and explores its possible regulatory network and functional role by identifying the distribution,evolutionary relationship,and changes in transcription levels of this family in various seaweeds.Six new CPF members were identified from the genomes of S.japonica and U.pinnatifida,and 94 CPF members from other different species were collected for phylogenetic analysis.Phylogenetic analysis divided CPF members into five subgroups.The results of RNA-seq and q PCR indicated that the Cryptochrome-DASH1(CRY-DASH1)and cyclopropane pyrimidine dimer dimer(CPD)genes in S.japonica may both play a role in light response and S.japonica gametophyte development.The protein interaction network of Sj CPF members showed that there were circadian rhythm protein Timeless homologous genes in E.siliculosus,which were located at the core of the Es CRY protein interaction network,and Timeless proteins were also identified in S.japonica.This suggests that Es CPF and Sj CPF members may transmit information by interacting with downstream Timeless genes.These results can provide new information for subsequent studies on the function and regulatory pathways of CPF in S.japonica. |
