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We isolated the Arabidopsis drought-resistant mutant csm1-1 and cloned the CSM1 gene (previously called RCI3) which encodes a kind of peroxidase. In this study, we showed that the mutant csm1-1 was more tolerant to selenium (Se) stress than the wild-type, and that the mutant csm1-1 accumulated similar Se content compared with the wild-type when subjected to Se stress. Further analysis revealed that the Se resistance of mutant csm1-1 was associated, at least in part, with the enhanced activities of antioxidant enzymes GSH-POD (glutathione peroxidase) and POD (peroxidase). In addition, enhanced Se resistance of the mutant csm1-1 was partially GSH dependent, which was related to the higher expression level of GSH1 gene involved in GSH synthesis and consequently increased GSH content.

The effects of sodium nitroprusside (SNP, a donor of NO) on cadmium (Cd) and copper (Cu) toxicity in ryegrass seedlings (Lolium perenne L.) on plant growth, chlorophyll content, the accumulation of superoxide anion (O 2 ·− ), lipid peroxidation, and the activities of antioxidant enzymes were studied. Cd, Cu, and especially Cd+Cu caused serious chlorosis, inhibited the growth of ryegrass seedlings, and increased dramatically the accumulation of Cd and/or Cu in both shoots and roots. However, the addition of 100 μM SNP alleviated significantly the toxic effects induced by Cd or Cu, and especially by Cd+Cu, which was manifested in the increased plant growth, chlorophyll content, and the activation of antioxidant enzymes. Moreover, exogenous NO improved effectively the absorption of mineral elements. In addition, exogenous NO diminished markedly the accumulation of reactive oxygen species (ROS), malondialdehyde (MDA), and proline, but increased the content of ascorbic acid (AsA) and inhibited the translocation of Cd and Cu from roots to shoots. These data also suggested that the alleviating effect of NO may be better when the metal stresses are more serious. NO might act as one of the potential antioxidants to improve plant resistance to the Cd and/or Cu stress.

The interactive effects of salicylic acid (SA) and nitric oxide (NO) on alleviating cadmium (Cd) toxicity in peanut (Arachis hypogaea L.) were studied. Seedlings of two cultivars (Huayu 22 — a big seed type, and Xiaobaisha — a small seed type) were treated with 200 μM CdCl2 without or with 0.1 mM SA or 0.25 mM sodium nitroprusside (SNP, an NO donor). Results show that the Cd exposure depressed the plant growth of both the cultivars but more of Huayu 22 than of Xiaobaisha. Exogenous SA and NO alleviated Cd toxicity in both the peanut cultivars: they improved growth, chlorophyll content, photosynthesis, and mineral nutrition. Furthermore, exogenous SA or NO decreased oxidative stress by increasing activities of antioxidant enzymes and content of non-enzymatic antioxidants. Besides, in roots and leaves of both the cultivars, exogenous SA and NO increased Cd accumulation in the cell wall and decreased Cd distribution to organelles. In particular, the effect of SA+SNP was most obvious.

The study aimed to test the effects of sodium nitroprusside [SNP, a nitric oxide (NO) donor], supplied with different approaches on cadmium (Cd) toxicity in lettuce seedlings (Lactuca sativa) in a pot experiment. SNP (8.94 mg) was applied into Cd-contaminated soil directly or added into a capsule, a paper bag, starch-coated granules, or foliar application. Cd (50 mg kg− 1) reduced chlorophyll content, caused oxidative stress, increased Cd accumulation in roots and leaves, and inhibited the uptake of calcium (Ca), magnesium (Mg), and iron (Fe). The addition of exogenous NO in Cd-contaminated soil increased chlorophyll content, improved antioxidant enzyme activities, promoted the uptake of Ca, Mg, and Fe, reduced Cd-induced oxidative damages, and inhibited Cd transferred from roots to shoots. Moreover, SNP supplied with different approaches had varied effects on Cd tolerance of lettuce seedlings. The alleviated effect of SNP applied into soil directly was the worst, and the three SNP slow release materials ...

Whereas chronological age (CA) cannot distinguish functional differences among individuals of the same age, the biological age (BA) may be used to reflect the functional state of the body. The purpose of this study was to construct an integral formula of the BA, by using principle component analysis (PCA).The vital organ function of 505 healthy individuals of Han origin (age 35-91 years) was examined. A total of 114 indicators of cardiovascular, pulmonary, and brain functions, and clinical, inflammatory, genetic, psychological, and life habit factors were assessed as candidate indicators of aging. Candidate indicators were submitted with CA to correlation and redundancy analyses. The PCA method was used to build an integral formula of the BA for the population.Seven biomarkers were selected in accordance with a certain load standard. These biomarkers included the trail making test (TMT), pulse pressure (PP), mitral valve annulus ventricular septum of the peak velocity of early filling (MVES), minimum carotid artery intimal-medial thickness (IMTmin), maximum internal diameter of the carotid artery (Dmax), maximal midexpiratory flow rate 75/25 (MMEF75/25), and Cystatin C (CysC). The formula for the BA was: BA = 0.0685 (TMT) + 0.267 (PP) - 1.375 (MVES) + 22.443 (IMTmin) + 2.962 (Dmax) - 2.332 (MMEF75/25) + 16.104 (CysC) + 0.137 (CA) + 0.492.Several genetic and lifestyle indicators were considered as candidate markers of aging. However, ultimately, only markers reflecting the function of the vital organs were included in the BA formula. This study represents a useful attempt to employ multiple indicators to build a comprehensive BA evaluation formula of aging populations.

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.

Porous copolymers based on divinylbenzene (DVB) and methyl acrylate (MA) were prepared by suspension polymerization in the presence of toluene as porogen. By using purified DVB (98.8%), the resulting MA/DVB copolymers with a wide range of DVB contents were found to be able to swell in water directly, although both the homopolymers derived from DVB and MA are hydrophobic. The amounts of DVB and MA in the copolymers affect the water-swelling behavior profoundly. However, the direct swelling in water occurs only after the DVB or MA content reaches a critical value, and the effect of the MA content will be significant only when the DVB content is at a high level. The latter observation reflects the combined effect of the cross-linking density and the polymer polarity on the swelling ability of the MA/DVB copolymers in water. The nature of the direct swelling of these hydrophobic porous copolymers in water was discussed by considering both factors: the existence of the inner stresses in the strained polymer n...

Using a potted experiment, we studied the effect of slow-release nitric oxide (NO) on the physiological characteristics of cotton seedlings subjected to salt stress (585 mg/kg NaCl). Sodium nitroprusside (SNP, an NO donor, 2.62 mg) was applied either directly to the soil, via slow release methods (slow-release bags, slow-release capsules, or slow-release particles), or via foliar application. NaCl decreased plant weight and chlorophyll content and increased electrolyte leakage and the contents of proline, ascorbic acid (ASA), and Na. NaCl also induced oxidative stress, as indicated by elevated levels of lipid peroxidation and ROS production. Foliar spray of SNP (0.09 mM) enhanced plant growth, promoted ion absorption and transport, and increased enzyme activity. Slow-released NO increased the levels of chlorophyll, ASA, and proline; promoted the uptake of K, Ca and Mg; and decreased Na. Moreover, increases in SOD and CAT activity were demonstrated to counter oxidative stress. However, different methods of SNP application have different effects on salt-tolerance. Foliar application was optimal. Slow-release NO, especially slow-release particles, was better able to alleviate NaCl toxicity compared with direct application of NO to the soil.