Proteomic and Biochemical Evidence Involving Root Cell Wall Biosynthesis and Modification, Tricarboxylic Acid Cycle, and Glutathione Metabolism in Cultivar-Dependent Cd Accumulation of Water Spinach (Ipomoea aquatica).

Proteomic analysis and biochemical tests were employed to investigate the critical biological processes responsible for the different cadmium (Cd) accumulations between two water spinach (Ipomoea aquatica) cultivars, QLQ and T308. QLQ, with lower shoot Cd accumulation and translocation factor than T308, possessed higher expression of cell wall biosynthesis and modification proteins in roots, together with higher lignin and pectin contents, higher pectin methylesterase activity, and lower pectin methylation. The results demonstrated that QLQ could more effectively restrict root-to-shoot Cd translocation by compartmentalizing more Cd in root cell walls. In contrast, T308 showed higher expression of the tricarboxylic acid (TCA) cycle, glutathione (GSH) metabolism, and heavy metal transporter proteins, accompanied by higher GSH content and glutathione S-transferase (GST) and glutathione reductase (GR) activity, which accelerated Cd uptake and translocation in T308. These findings revealed several critical biological processes responsible for cultivar-dependent Cd accumulation in water spinach, which are important for elucidating Cd accumulation and transport mechanisms in different cultivars.

Molecular and biochemical mechanisms underlying boron-induced alleviation of cadmium toxicity in rice seedlings.

Both cadmium (Cd) contamination and boron (B) deficiency in farmland soils pose a threat to the yield and quality of crops in Southern China. The present study investigated the mechanisms by which B reduces Cd accumulation in rice (Oryza sativa) seedlings. Boron supplementation partially restored the decline in shoot and root biomass caused by Cd treatment (26% and 33%, respectively), with no significant difference between the B+Cd and control groups. We also found that B significantly reduced shoot and root Cd concentrations (by 64% and 25%, respectively) but increased Cd concentration (by 43%) and proportion (from 38% to 55%) in root cell walls. Transcriptome analysis and biochemical tests suggested that B supplementation enhanced lignin and pectin biosynthesis, pectin demethylation, and sulfur and glutathione metabolism. Moreover, B decreased the expression of some Cd-induced transporter-related genes (i.e., HMA2, Nramp1, and several ABC genes). These results indicate that B relieved Cd toxicity and reduced Cd accumulation in rice seedlings by restraining Cd uptake and translocation from root to shoot by improving Cd tolerance and chelation ability. These novel findings would benefit further investigations into how B influences Cd uptake, translocation, detoxification, and accumulation in crops.

Screening of the proteins related to the cultivar-dependent cadmium accumulation of Brassica parachinensis L.

Cultivar-dependent cadmium (Cd) accumulation was principal in developing Cd-pollution safe cultivars (PSCs). Proteins related to different Cd accumulations of the low-Cd-accumulating (SJ19) and high-Cd-accumulating (CX4) cultivars were investigated by iTRAQ analysis. Higher Cd bioaccumulation factors and translocation factor in CX4 than in SJ19 were consistent with the cultivar-dependent Cd accumulations. The Cd uptake was promoted in CX4 due to its higher expression of Cd-binding proteins and the lower expression of Cd-efflux proteins in roots. What's more, significantly elevated thiol groups (PC2 and PC3) in CX4 under Cd stress might contribute to the high Cd accumulation in roots and the root-to-shoot translocation of Cd-PC complex. Up-regulated proteins involved in cellulose biosynthesis and pectin de-esterification in SJ19 enhanced the Cd sequestration of root cell walls, which was considered as the predominant strategy for reducing Cd accumulation in shoots. The present study provided novel insights in the cultivar-dependent Cd accumulation in shoots of B. parachinensis.

[Effect of Muxiang Shunqi Pill on Digestive Disorders of Prephase Uremia Patients and Its Mechanism].

Objective To observe the effect of Muxiang Shunqi Pill (MSP) on digestive disorders of prephase uremia patients, and to study its underlying mechanism. Methods A total of 40 prephase uremia patients with gastrointestinal symptoms were randomly and equally assigned to the MSP group and the Mosapride group. Besides, 20 subjects with normal physical examinations were recruited as the control. Patients in the MSP group took MSP, 6 g each time, three times per day, taken 30 min after dinner. Those in the Mosaprido group took Mosapride Tablet (MT) , 5 mg each time, three times per day, taken 30 min before diner. The therapeutic course for all was 4 weeks. The clinical curative effect was observed. Electrogastrogram, serum levels of gastrin (GAS) and motilin (MTL) , safety and recurrence rate were evaluated. Results The total effective rate was 90% (18/20) and the recurrence rate was 15% (320) in the MSP group, higher than those of the Mosapride group [60%(12/20) , X² =4. 80, P =0. 025; 45% (9/20) , X² =4. 29, P =0. 025]. Compared with before treatment in the same group, the percentage of normal rhythm increased, the bradygastria rate was lowered, serum levels of GAS and MTL increased in the two groups after treatment (P <0. 05, P <0. 01). Compared with the Mosapride group, the bradygastria rate decreased more obviously, serum levels of GAS and MTL were increased more in the MSP group (P <0. 05, P <0. 01). Conclusion MSP could effectively improve digestive disorders of prephase uremia patients, which might be achieved through promoting gastrointestinal motility and regulating ser- um levels of gastrointestinal hormones.