Proteomic and metabolic profile analysis of low-temperature storage responses in Ipomoea batata Lam. tuberous roots

Abstract

Background: Sweetpotato (Ipomoea batatas L.) is one of the seven major food crops grown worldwide, with 70-75% of production in China. Cold stress often can cause protein expression pattern and substance contents variations for tuberous roots of sweetpotato during low-temperature storage. Recently, we developed proteometabolic profiles of the fresh sweetpotatoes (cv. Xinxiang) in an attempt to discern the cold stress-responsive mechanism of tuberous root crops during post-harvest storage.Results: For roots stored under 4℃ condition, the CI index, REC and MDA content in roots were significantly higher than them at control temperature (13℃). The activities of SOD, CAT, APX, O2.- producing rate, proline and especially soluble sugar contents were also significantly increased. Most of the differentially expressed proteins (DEPs) were implicated in pathways related to metabolic pathway (~22%), especially phenylpropanoids (~10%) and followed by starch and sucrose metabolism (~3%). Proteins including L-ascorbate peroxidase 3 and catalase were down-regulated during low temperature (4℃) storage. α-amylase, sucrose synthase and fructokinase were significantly up-regulated in starch and sucrose metabolism, while β-glucosidase, glucose-1-phosphate adenylyl-transferase and starch synthase were opposite. Furthermore, metabolome profiling revealed that glucosinolate biosynthesis, tropane, piperidine and pyridine alkaloid biosynthesis as well as protein digestion and absorption played a leading role in metabolic pathways of sweetpotato roots. More importantly, leucine, tryptophan, tyrosine, isoleucine and valine were all significantly up-regulated in glucosinolate biosynthesis. Data are available via ProteomeXchange with identifier PXD017728.Conclusions: Our proteomic and metabolic profile analysis of sweetpotato roots stored at low temperature reveal that the antioxidant enzymes activities, proline and especially soluble sugar content were significantly increased. Most of the DEPs were implicated in phenylpropanoids and followed by starch and sucrose metabolism. The discrepancy between proteomic (L-ascorbate peroxidase 3 and catalase) and biochemical (APX/CAT enzyme activity) data may be explained by higher H2O2 levels and increased glutathione and ascorbate redox states, which enhanced the CAT/APX enzyme activity indirectly. Glucosinolate biosynthesis played a leading role in metabolic pathways of sweetpotao roots. More importantly, leucine, tryptophan, tyrosine, isoleucine and valine were all significantly up-regulated in glucosinolate biosynthesis.

Identification of QTLs for stagnant flooding tolerance in rice employing genotyping by sequencing of a RIL population derived from Swarna × Rashpanjor

“…Efficient carbohydrate metabolism and starch biosynthesis under waterlogging stress are thus very crucial tolerance responses for plants (Lothier et al 2020). We observed the presence of a functional gene of the large subunit of glucose-1-phosphate adenylyltransferase which is involved in biosynthesis of ADP-Glucose, an important metabolite for starch biosynthesis in plants (Cui et al 2020). Apart from this, found few genes of sulfur transport/metabolism in plants that might play a key role in sulfur uptake and metabolism (Gallardo et al 2014) and hypoxia-induced sulpho-lipid biosynthesis in plants (Klecker et al 2014).…”