Identification Of CCD And ALMT Gene Families And Their Interacting MiRNAs And The Role Of TDT Gene In Potato During Drought Adaptation

Potato(Solanum tuberosum L.)is the fourth largest food crop in the world,but due to its shallow root system,it is very sensitive to drought and water scarcity.Drought stress leads to the inhibition of potato growth,seriously affecting the yield and quality of potatoes.Previous research in our laboratory has shown that drought exercise can improve the tolerance of potatoes to subsequent drought stress,and drought response genes regulate plant growth and development at the molecular level,responding to and adapting to drought stress.Based on the results of transcriptome sequencing and miRNA sequencing previously completed by our laboratory,this study selected highly responsive genes under drought stress,namely carotenoid cleavage dioxygenase(CCD),aluminumactivated malate transporter(ALMT),and vacuolar membrane dicarboxylate transporter(TDT).The identification and analysis of their gene family members at the whole genome level were conducted.Their systematic evolution,conserved domains,chromosome location,expression characteristics,and the relationship between member genes and miRNA in potato response to drought were analyzed.Some important genes were cloned and functionally verified preliminarily.The main results are as follows:1.A total of 17 CCD genes were identified in the potato genome,all located on 5chromosomes and classified into 6 subfamilies,encoding polypeptides with 174-1,115 amino acid residues.Gene expression analysis indicated that members such as NCED1,NCED6 and CCD4 of the CCD gene family respond to drought stress,suggesting that they are key genes regulating drought stress in the CCD gene family.A total of 777 miRNAs targeted the regulation of the 17 members of the potato CCD family.The gene expression of StCCDs and corresponding miRNAs showed a negative regulatory relationship,and this interaction between StCCDs and miRNAs may participate in the process of enhancing potato drought resistance through drought training.Gene cloning and overexpression verification suggested that StCCDs are involved in drought stress response and may be candidate genes for precise molecular breeding of droughtresistant potatoes.2.The potato ALMT gene family consists of 19 members with protein encoding195-665 amino acids,which are mainly located on the cell membrane and contain ALMT(PF11744),FUSC(PF04632),and FUSC＿2(PF13515)domains.The 19 family members can be divided into 7 groups,located on 8 chromosomes,including 2 pairs of tandem repeats and 5 pairs of scattered repeats.The expression patterns of each member under different non-biological stress,hormones,and tissues show significant differences,as revealed by expression profiling and qRT-PCR analysis.The analysis of miRNA sequencing data shows that 1,096 miRNAs regulate the 19 members of the ALMT gene family.Four miRNAs that are significantly expressed under drought stress were selected for expression profiling analysis,and the correlation between their targeting ALMT gene expression was analyzed,showing a significant negative correlation,indicating that miRNAs negatively regulate the expression of ALMT genes under drought stress.3.Through bioinformatics analysis,expression profiling analysis,identification of interacting proteins,and qRT-PCR analysis of potato StTDT gene,knockout vectors and overexpression of StTDT gene were constructed.Compared with the wild-type control,the growth rate of potato material was slow,suggesting that StTDT gene may play a role in potato response to drought stress,providing a candidate gene for precise molecular breeding of drought-resistant potatoes in the future.This study conducted a whole-genome analysis on the CCD,ALMT family,and TDT genes that respond strongly to drought,and analyzed the interaction between certain highly responsive family members and miRNAs during drought hardening,revealing a correlation between miRNA expression regulation and corresponding genes.The results of this study help to better understand the function of potato CCD,ALMT gene families and TDT genes,their interactions with corresponding miRNAs,and how these interactions regulate potato response and adaptation to drought,providing references for future molecular breeding to improve potato drought resistance.