Screening And Expression Of Salt-Related ARF/NAC/bHLH Transcription Factors In Sugar Beet

Soil salinization has a great impact on crop yield and quality.Therefore,studying the salt tolerance mechanism of crops and breeding salt-tolerant lines has always been the focus of agricultural research.In recent years,transcription factors have been shown to be widely involved in the regulation of stress response processes in plants,playing an important role in plant salt tolerance,in which the transcription factors ARF,NAC and bHLH families have been shown to be salt tolerant.Sugar beet is an important raw material in China's sugar industry,and the main sugar beet production area is mostly in areas with serious salinization.Therefore,studying the salt tolerance mechanism of sugar beet can provide ideas for breeding salt-tolerant sugar beet,which is of significance to China's sugar industry.In this study,300 mM NaCl solution was used to treat the three pairs of true seedlings of the beet "O68" line for 24 h salt stress.The combination of bioinformatics and molecular biology experiments was used to study the beet "O68" under salt stress conditions.The expression levels of ARF,NAC and bHLH transcription factor members in the leaves and roots of the lines were changed,and the following results were obtained:According to the ARF conserved domain,the whole genome database of sugar beet was screened,and 14 beet ARF transcription factor family genes were identified,which can translate 16 transcription factor proteins.Most ARF proteins have 3 domains,only a few have only two domains,ARF protein,etc.The average electrical point is 6.13,except for chromosome 3,ARF protein can be divided into 6 categories according to homology clustering.The distribution of exons/introns and the morphology of similar ARF are similar,subcellular Positioning shows that ARF is localized in the nucleus.The expression level of ARF transcription factor was analyzed by real-time PCR.ARF members associated with salt tolerance in sugar beet leaves and roots were obtained.According to the NAC conserved domain,the sugar beet genome database was screened,54 beet NAC transcription factor family genes were identified,59 transcription factor proteins could be translated,NAC proteins all have NAM domain,NAM domain has 5 subdomains,NAC protein The average isoelectric point is 6.51,and the chromosomes of NAC are clustered.The NAC proteins can be divided into two categories according to homology clustering.The first category contains 11 subclasses,the second category contains 3 subclasses,and the same type of NAC.The distribution of exons/introns and the morphology of the motifs are similar.Based on the results of expression profiling,ARF transcription factor family members that may be related to salt tolerance response were selected,and the expression levels of these transcription factors were analyzed by real-time PCR to verify the consistency of expression analysis.Salt-related NAC members in sugar beet leaves and roots were obtained.The transcription factor NAC member hzcx with significant expression changes and large expression was selected for cloning and sequencing.The hzcx sequence was analyzed.It consisted of 303 amino acids with a molecular formula of C1558H2365N415O449S17,a molecular weight of 34638.45 and an isoelectric point of 8.15.Protein interaction analysis revealed that hzcx interacts with ethylene reactive elements,heat shock factors,hsp40 chaperone family members,and proteins with SANT domains.The sequence was submitted to the GenBank database,GenBank ID: MK982093.According to the bHLH conserved domain,the whole genome database of sugar beet was screened,and 106 members of the beet bHLH transcription factor family were identified,which can be translated into 109 transcription factor proteins.The average isoelectric point of bHLH protein is 6.53,and the chromosome localization of bHLH is clustered,bHLH Proteins can be classified into 20 categories according to homology clustering.The distribution of exons/introns and the morphology of similar bHLHs are similar.Based on the results of expression profiling,members of the bHLH transcription factor family that may be associated with salt tolerance response were selected,and the expression levels of these transcription factors were analyzed by real-time PCR to verify the consistency of the results of expression profiling.The bHLH members related to salt tolerance in sugar beet leaves and roots were obtained.Based on the results of protein interaction and previous studies,a preliminary salt-tolerant regulatory network was established,including the transmission of salt signals,the regulation between transcription factors,and finally the pathway to achieve salt tolerance.In this regulatory network,ARF,NAC and bHLH play an important role,especially the regulation of NAC transcription factors is extensive,and it plays an important role in plant salt tolerance.