To understand the functions of exogenous 24-Epibrassinolide (EBR) in enhancing the salt tolerance of wheat (T. aestivum L.) seedlings to salt stress, a hydroponic experiment was performed to investigate the effects of EBRon chlorophylls,root activity, H+-ATPase, malondialdehyde (MDA), electrolyte leakage, free proline, soluble protein, reactive oxygen species (ROS), antioxidant enzymes and minerals content in wheat plants subjected to non-stress conditions or salt stress (120 mM NaCl) with foliar application of EBR (1, 10 and 100 nM). Results showed that spray of low concentrations EBR (1 and 10 nM) under non-stress conditions could promote wheat plant growth. 120 mM NaCl induced osmotic stress, oxidative stress and imbalance in mineral nutrients absorption. However, EBR enhanced the ability of resistance to osmotic stress by increasing free proline and soluble protein content, and enhanced the ability of resistance to oxidative stress by increasing antioxidant enzymes activities. As a result of increase of chlorophyll content, root activity and H+-ATPase activity, the inhibition of K, Ca, Mg, Fe and Zn uptake was ameliorated and consequently, decline in plant growth induced by NaCl stress was alleviated. Based on these results, we conclude that EBR had a positive role in regulating wheat growth and development under salt stress, and spray of 10 nM EBR had the most significant alleviating effect against NaCl toxicity.

A pot experiment was conducted to study the effects of sodium nitroprusside (SNP, a nitric oxide [NO] donor) on cadmium (Cd) toxicity in ryegrass plants. In the present study, ryegrass plants subjected to Cd toxicity were treated with different concentrations of SNP (50, 100, 300 and 500 µM), SNP solution was poured into Cd-contaminated soil every seven days. Cd treatment inhibited the plants growth and the absorption of micronutrients, increased accumulation of Cd in both shoots and roots. In Cd-treated plants, the activities of antioxidant enzymes and the contents of proline, soluble protein and ascorbic acid (AsA) decreased dramatically, whereas the accumulation of superoxide anion (O2.-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased significantly. Addition of SNP significantly decreased O2.-, H2O2 and MDA accumulation in both shoots and roots of Cd-stressed plants, decreased the transport of Cd from roots to shoots, alleviated the inhibition of Ca, Fe, Mg and Zn absorption induced by Cd and promoted the plant growth. In SNP-treated plants, the chlorophyll content, the contents of proline, soluble protein and ascorbic acid, and the activities of superoxide dismutase, peroxidase and catalase increased considerably. Addition of 300 µM SNP had the most significant alleviating effect against Cd toxicity while the addition of 500 µM SNP had no significant effect with Cd treatment. Based on these results, we concluded that the optimal concentrations of exogenous SNP could alleviate Cd induced stress and promote ryegrass plant growth.

MicroRNAs (miRNAs) may be important mediators of the profound molecular and cellular changes that occur after traumatic brain injury (TBI). However, the changes and possible roles of miRNAs induced by voluntary exercise prior to TBI are still not known. In this report, the microarray method was used to demonstrate alterations in miRNA expression levels in the cerebral cortex of TBI mice that were pretrained on a running wheel (RW). Voluntary RW exercise prior to TBI: i) significantly decreased the mortality rate and improved the recovery of the righting reflex in TBI mice, and ii) differentially changed the levels of several miRNAs, upregulating some and downregulating others. Furthermore, we revealed global upregulation of miR-21, miR-92a, and miR-874 and downregulation of miR-138, let-7c, and miR-124 expression among the sham-non-runner, TBI-non-runner, and TBI-runner groups. Quantitative reverse transcription polymerase chain reaction data (RT-qPCR) indicated good consistency with the microarray results. Our microarray-based analysis of miRNA expression in mice cerebral cortex after TBI revealed that some miRNAs such as miR-21, miR-92a, miR-874, miR-138, let-7c, and miR-124 could be involved in the prevention and protection afforded by voluntary exercise in a TBI model.