AUTHOR=Ling Li-Juan , Wang Meng , Pan Chuan-Qing , Tang Dao-Bang , Yuan En , Zhang Yuan-Yuan , Chen Ji-Guang , Peng Da-Yong , Yin Zhong-Ping 

TITLE=Investigating the induction of polyphenol biosynthesis in the cultured Cycolocarya paliurus cells and the stimulatory mechanism of co-induction with 5-aminolevulinic acid and salicylic acid

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2023.1150842

DOI=10.3389/fbioe.2023.1150842

ISSN=2296-4185

ABSTRACT=<p><bold>Background:</bold> Plant cell culture technology is a potential way to produce polyphenols, however, this way is still trapped in the dilemma of low content and yield. Elicitation is regarded as one of the most effective ways to improve the output of the secondary metabolites, and therefore has attracted extensive attention.</p><p><bold>Methods:</bold> Five elicitors including 5-aminolevulinic acid (5-ALA), salicylic acid (SA), methyl jasmonate (MeJA), sodium nitroprusside (SNP) and <italic>Rhizopus Oryzae</italic> Elicitor (ROE) were used to improve the content and yield of polyphenols in the cultured <italic>Cyclocarya paliurus (C. paliurus)</italic> cells, and a co-induction technology of 5-ALA and SA was developed as a result. Meanwhile, the integrated analysis of transcriptome and metabolome was adopted to interpret the stimulation mechanism of co-induction with 5-ALA and SA.</p><p><bold>Results:</bold> Under the co-induction of 50 μM 5-ALA and SA, the content and yield of total polyphenols of the cultured cells reached 8.0 mg/g and 147.12 mg/L, respectively. The yields of cyanidin-3-O-galactoside, procyanidin B1 and catechin reached 28.83, 4.33 and 2.88 times that of the control group, respectively. It was found that expressions of TFs such as <italic>CpERF105, CpMYB10</italic> and <italic>CpWRKY28</italic> increased significantly, while <italic>CpMYB44</italic> and <italic>CpTGA2</italic> decreased. These great changes might further make the expression of <italic>CpF3′H</italic> (flavonoid 3′-monooxygenase), <italic>CpFLS</italic> (flavonol synthase), <italic>CpLAR</italic> (leucoanthocyanidin reductase), <italic>CpANS</italic> (anthocyanidin synthase) and <italic>Cp4CL</italic> (4-coumarate coenzyme A ligase) increase while CpANR (anthocyanidin reductase) and <italic>CpF3′5′H</italic> (flavonoid 3′, 5′-hydroxylase) reduce, ultimately enhancing the polyphenols accumulation</p><p><bold>Conclusion:</bold> The co-induction of 5-ALA and SA can significantly promote polyphenol biosynthesis in the cultured C. <italic>paliurus</italic> cells by regulating the expression of key transcription factors and structural genes associated with polyphenol synthesis, and thus has a promising application.</p>