BMC Plant Biology最新文献

Background: Calotropis procera is a medicinally significant plant valued for its diverse bioactive pharmacological compounds. Environmental stimuli, such as static magnetic field (SMF), can act as potent elicitors, altering its metabolic pathways. This study investigates the impact of SMF exposure (150 mT) for 0, 1, 2, or 3 h on primary and secondary metabolite components, antioxidant responses, and gene expression of C. procera callus cultures.

Results: SMF induced significant, time-dependent metabolic changes. Soluble sugars increased 1.6-fold after 3 h, while soluble proteins declined to 0.47-fold of controls. Phenylpropanoid biosynthesis was markedly enhanced, with phenolics and flavonoids increasing 7.5- and 3.2-fold, respectively. HPLC analysis revealed a coordinated upregulation of phenolic and flavonoid compounds. Kaempferol and ellagic acid showed a 115% increase, while gallic acid and quinic acid derivative increased by over 116%. Conversely, cardiac glycosides and saponins were suppressed. Concurrently, SMF exposure triggered ROS, with levels of O₂^-•, H₂O₂, OH^•, and MDA increasing by 462, 117, 160, and 233%, respectively. However, the antioxidant capacity significantly improved, showing 6.91 and 25.93% increases in AsA and GSH levels, alongside 2.32- and 0.30-fold increases in DPPH^• scavenging and total antioxidant activity. CAT, POD, and SOD activities declined, while GR activity increased. Gene expression analysis revealed profound upregulation of phenylpropanoid pathway enzymes, particularly PAL (549.89-fold), CHI (100.60-fold), and F3H (50.90-fold).

Conclusions: These results demonstrated that SMF elicited coordinated metabolic reprogramming in C. procera, enhancing non-enzymatic antioxidants and phenylpropanoid biosynthesis while suppressing steroidal pathways and enzymatic antioxidant activity, highlighting its potential as a biophysical tool for metabolic engineering.

Background: Postharvest pepper fruits undergo quality deterioration including water loss, shrinkage and nutritional decline, which limits their commercial value. Notably, nano-silicon (SiNPs) improves postharvest vegetable quality, but its regulatory mechanism on pepper storage quality, especially metabolic changes, remains unclear. Therefore, this study explored SiNPs effects on P70 pepper phenotype, storage quality and metabolism to optimize postharvest preservation.

Results: SiNPs treatment significantly improved P70 pepper fruits storage quality. Under roomtemperature (RT) and low temperature (LT) storage conditions, SiNPs treatment (RT-NP, LT-NP) effectively alleviated shrinkage, water loss, and hardness decline. After 6 days of storage, LT-NP group had 1.09-fold higher hardness than LT group, while LT group weight loss was 1.46-fold that of LT-NP. For nutritional quality indicators, SiNPs treatment maintained higher contents of vitamin C, flavonoids, soluble solids and soluble sugar. In terms of antioxidant capacity, SiNPs treatment enhanced the activities of superoxide dismutase, peroxidase and catalase; LT-NP had 1.11-fold higher SOD at 6 days and 1.54-fold higher POD at 4 days than LT. Metabolomic analysis detected1041 metabolites, mainly including flavonoids (22.1%) and phenolic acids (13.7%). Compared with LT group, LT-NP had 164 up- and 79 down-regulated differential metabolites, enriched in flavonoid biosynthesis, starch-sucrose and amino acid metabolism. LT-NP up-regulated flavonoids (Galangin, Apigenin), D-Sucrose and activated polyamine biosynthesis.

Conclusions: SiNPs improves P70 pepper postharvest quality by reducing water loss, maintaining hardness and nutrients. Collectively, the mechanism involves enhanced antioxidant enzyme activity and regulated key metabolites in flavonoid, sugar and amino acid pathways, supporting SiNPs application in pepper postharvest preservation.

Background: Nitrogen (N) and phosphorus (P) are essential macronutrients that drive plant growth and photosynthesis; their deficiencies alters both plant physiology and metabolism. However, the molecular mechanisms by which Ilex chinensis responds to N and P starvation remain largely unknown.

Results: We subjected two-year-old I. chinensis seedlings to 10 weeks of low N (LN) and low P (LP) stress and profiled the leaf transcriptome. Both stresses restricted shoot elongation but stimulated lateral root proliferation, with the strongest phenotype under LN₂ and LP₂ regimes. Relative to the control, LN₂ group exhibited 2.1- to 3.9-fold increases in nitrate reductase (NR), glutamine synthetase (GS), superoxide dismutase (SOD), peroxidase (POD), and malondialdehyde (MDA) (P < 0.01). LP₂ group displayed 1.7- to 2.4-fold higher acid phosphatase (ACP), SOD, POD activity, anthocyanin content, and MDA (P < 0.01). Transcriptomic analysis revealed that pathways enriched under N and P deficiency were responsive to plant growth, root development, and N and P uptake.

Conclusions: Our data reveal the integrated physiological and transcriptional adjustments that allow I. chinensis to cope with N and P deficiency stress, and identifies potential target genes for improving nutrient use efficiency. These findings provide new insights into the physiological and molecular responses of I. chinensis to N and P deficiency stress and offer valuable information for optimizing its cultivation under nutrient-limited conditions.