Molecular Mechanism Of Light Factor Affecting The Synthesis Of Phlorizin From Lithocarpus Polystachyus Rehd

Lithocarpus polystachyus Rehd is an important medicinal plant that grows in southern China.Its roots,stems,and leaves can be used as medicines.It has various effects such as blood sugar lowering and anti-tumor effects.Phlorizin is its main active substance.Light has an effect on the synthesis of flavonoids in most plants,so it is crucial to study the effect of different light conditions on the synthesis of phlorizin in L.polystachyus.To solve this problem,the study cultivated L.polystachyus under different light quality,light intensity,and photoperiod conditions and sequenced the transcriptome,and compared the sequencing data results using bioinformatics methods.The results showed that each sample obtained a high-quality clean reading of more than 6 Gb,assembled from scratch to 177,894 unigenes,with an average length of 560 bp,and 43.13% of unigenes were annotated in at least one of the searched public databases.The light treatments resulted in 5,977–8,027 differentially expressed genes(DEGs),which were functionally annotated based on the GO and KEGG databases.Genes encoding transcription factors from 89 families were differentially expressed after the light treatments,implying these transcription factors are photoresponsive.Phenylalanine ammonia lyase(PAL)and 4-coumarate-Co A ligase(4CL)are the key enzymes for the accumulation of phlorizin.The transcription levels of PAL2,PAL,4CL1(DN121614),4CLL7,and 4CL1(DN102161)were positively correlated with phlorizin accumulation,suggesting that these genes are important for phlorizin biosynthesis.An ultra-highperformance liquid chromatography method was used to quantify the phlorizin content.Phlorizin accumulated in response to the green light treatment and following appropriate decreases in the light intensity or appropriate increases in the duration of the light exposure.The green light,2000 lx,and 3000 lx treatments increased the PAL activity of L.polystachyus,but the regulatory effects of the light intensity treatments on PAL activity were relatively weak.This study represents the first comprehensive analysis of the light-induced transcriptome of L.polystachyus.The study results may form the basis of future studies aimed at elucidating the molecular mechanism underlying phlorizin biosynthesis in L.polystachyus.Moreover,this study may be relevant for clarifying the regulatory effects of light on the abundance of bioactive components in medicinal plants.Figure 23;Table 10;Reference 124...