沙生蜡菊响应冻害胁迫的生理指标检测及转录组分析OA

To investigate the molecular regulation mechanisms of Helichrysum arenarium in response to freezing stress,1-month-old wild Helichrysum arenarium seedlings were used as experimental ma-terials.Leaves were collected at 0,0.5,1,2,and 3 h under freezing stress at-5℃.Physiological in-dex analysis and transcriptome analysis were conducted to identify key genes and metabolic pathways involved in the freezing stress response of H.arenarium.The results showed that as the duration of freezing stress increased,the relative electrical conductivity of leaves increased significantly,whereas the chlorophyll content of leaves decreased significantly,and the photosynthetic parameters of seed-lings were also affected.However,freezing stress increased the accumulation of flavonoids.A total of 370 candidate differentially expressed genes(DEGs)were screened among the five treatment groups.GO analysis showed that the candidate DEGs were mainly enriched in binding,cellular processes,met-abolic processes and catalytic activity.KEGG enrichment analysis showed that the candidate DEGs in response to freezing stress were enriched in pathways such as cysteine and methionine metabolism and flavonoid biosynthesis.Transcription factor analysis showed that WRKY was downregulated and ERF was upregulated.Twelve DEGs related to freezing injury were selected for qRT-PCR verification,indi-cating that CHS,CHI and ERF genes positively regulated the freezing-injury response of H.arenar-ium,whereas WRKY transcription factors played a negative regulatory role.In summary,Helichry-sum arenarium responds to freezing stress through amino acid metabolism and flavonoid biosynthesis,and these results provide a theoretical basis for resistance breeding and artificial cultivation of Heli-chrysum arenarium.