Metabolomic and transcriptomic analysis of Lycium chinese and L. ruthenicum under salinity stress

High soil salinity often adversely affects plant physiology and agricultural productivity of almost all crops worldwide, such as the crude drug known as wolfberry. However, the mechanism of this action in wolfberry is not fully understood yet.Here in this study, we studied different mechanisms potentially in Chinese wolfberry (Lycium chinese, LC) and black wolfberry (L. ruthenicum, LR) under salinity stress, by analyzing their transcriptome, metabolome, and hormone changes. The hormone detection analysis revealed that the ABA content was significantly lower in LR than LC under normal condition, and increased sharply under salinity stress in LR but not in LC. The transcriptome analysis showed that the salinity-responsive genes in wolfberry were mainly enriched in MAPK signaling, amino sugar and nucleotide sugar metabolism, carbon metabolism, and plant hormone signal transduction pathways in LC, while mainly related to carbon metabolism and protein processing in endoplasmic reticulum in LR. Metabolome results indicated that LR harbored higher flavone and flavonoid contents than LC under normal condition. However, the flavone and flavonoid contents were hardly changed in LR, but increased substantially in LC when exposed to salinity stress.Our results adds ABA and flavone to mechanism understanding of salinity tolerance in wolfberry. In addition, flavone plays a positive role in resistance to salinity stress in wolfberry.