Transcriptome Sequencing-Assisted Mining of Salt-Tolerant Genes in Phenylpropane Biosynthesis Pathway of Lonicera japonica

Huang Luyao; Li Zhuangzhuang; Duan Tongyao; Wang Bin; Li Xuejie; Li Jia

doi:10.14083/j.issn.1001-4942.2026.03.001

Abstract：Honeysuckle(Lonicera japonica Thunb.)is a traditional medicinal plant in China.In this study,transcriptome sequencing and bioinformatics analysis were conducted using the leaves of"Huajin 6"honeysuckle treated with 300 mmol·L-1 NaCl for 0 h(CK),12,24,48 and 72 h to understand the regulation of secondary metabolites of honeysuckle under salt stress.The results showed that the gene expression level of the samples treated with NaCl for 12 h had lower correlation with that for 0,24,48 and 72 h.At 12,24,48 and 72 h after NaCl treatment,1 803,903,1 833 and 1 748 differentially expressed genes(DEGs)were screened out with 227 overlapping genes,and the number of unique DEGs was the highest at 12 h.The sec-ondary metabolic pathway,phenylpropane biosynthesis pathway,and α-linolenic acid metabolism pathway were all activated at the four time points.There were 94,36,57 and 44 DEGs up-regulated in the secondary metabolic pathway at 12,24,48 and 72 h respectively,including 4 overlapping DEGs,namely,mannitol de-hydrogenase(MTD),isoflavin synthase(STR),triacylglycerol lipase(TGL)and ethanol dehydrogenase(ADH);there were 21,16,19 and 13 up-regulated DEGs in the phenylpropane biosynthesis pathway at 12,24,48 and 72 h respectively,with MTD up-regulated at all the 4 time points.At 12 h,6 genes in chlorogenic acid and luteolin biosynthesis pathway were significantly up-regulated,including one cinnamic acid 4-hydroxy-lase(C4H)gene,one hydroxycinnamoyl transferase(HCT)gene,two caffeoyl coenzyme A-O-methyltrans-ferase(CCoAOMT)genes,one chalcone synthase(CHS)gene,one chalcone isomerase(CHI)gene.There-fore,it was speculated that the mechanism of honeysuckle coping with salt stress at 12 h was different from that at 24,48 and 72 h.At 12 h,honeysuckle rapidly regulated the cellular responses at transcriptional level by inducing up-regulation of key genes in the phenylpropanoid metabolism pathway such as C4H,HCT,CCoAOMT,CHS and CHI genes in response to salt stress.With the extension of stress time,honeysuckle mainly regulated salt tolerance through mannitol synthesis,lipid metabolism,ethanol fermentation,etc.There-fore,the early and rapid response to salt stress,especially the early response of phenylpropane metabolism,was crucial to the salt tolerance of honeysuckle.