Yi-ping Chen

Effect of CO2 laser radiation on physiological tolerance of wheat seedlings exposed to chilling stress.

To determine the effect of CO2 laser pretreatment of wheat seeds on the physiological tolerance of seedlings to chilling stress, wheat seeds were exposed to CO2 laser radiation for 300 s. After being cultivated for 48 h at 25°C, the wheat seedlings were subjected to chilling stress for 24 h. Selected physiological and biochemical parameters were measured in 6‐day‐old seedlings. We observed that chilling stress enhanced the concentrations of malondialdehyde and oxidized glutathione while decreasing the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione in the wheat leaves compared with controls. When the chilling stress was preceded by CO2 laser irradiation, the concentrations of malondialdehyde and oxidized glutathione were decreased while the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione increased. Furthermore, chilling stress decreased the biomass, biophoton intensity and GHS/GSSG ratios of seedlings while these parameters increased when the seedlings were treated with CO2 laser irradiation prior to the chilling stress. The results suggest that a suitable dose of CO2 laser stimulation can enhance the physiological tolerance of wheat seedlings to chilling stress.

Bacterial communities in a crude oil gathering and transferring system (China).

Bacterial communities in crude oil and oil field production water samples from an oil gathering and transferring system in Changqing Oil field in China were investigated by 16S rRNA denaturing gradient gel electrophoresis (DGGE) analysis followed by gene cloning and sequencing. DGGE profiles showed that bacterial communities are far more rich in the water samples than that in the crude oil samples, and that bacteria related to Ochrobactrum sp. and Stenotrophomonas sp. were detected in all crude oil and oil field water samples. Bacteria related to Burkholderia sp., Brevundimonas sp., and Propionibacterium sp. were detected in the crude oil samples but not in water samples. Bacteria related to Hippea sp., Acidovorax sp., Arcobacter sp., Pseudomonas sp., Thiomicrospira sp., Brevibacterium sp., Tissierella sp. and Peptostreptococcus sp. were detected in the water samples but not in crude oil samples. Using an archaea-specific primer set, methanogens related to Methanomicrobials and Methanosarcinales were found in water samples but not in crude oil samples. The comparability of the microbial communities in the water and crude oil phase during the period of oil gathering and transferring process was 83.3% and 88.2%, respectively, indicating a stable structure of the microbial communities.

Response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings exposed to UV-B.

To determine the response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings, Isatis indigotica seedlings were subjected to UV-B radiation (10.08 kJ m-2) for 8 h day-1 for 8 days (PAR, 220 µmol m-2 s-1) and then exposed to He-Ne laser radiation (633 nm; 5.23 mW mm-2; beam diameter: 1.5 mm) for 5 min each day without ambient light radiation. Changes in free radical elimination systems were measured, the results indicate that: (1) UV-B radiation enhanced the concentration of Malondialdahyde (MDA) and decreased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in seedlings compared with the control. The concentration of MDA was decreased and the activities of SOD, CAT and POD were increased when seedlings were subjected to elevated UV-B damage followed by laser; (2) the concentration of UV absorbing compounds and proline were increased progressively with UV-B irradiation, laser irradiation and He-Ne laser irradiation plus UV-B irradiation compared with the control. These results suggest that laser radiation has an active function in repairing UV-B-induced lesions in seedlings.

Microwave treatment of eight seconds protects cells of Isatis indigotica from enhanced UV-B radiation lesions

Abstract To determine the role of microwaves in the stress resistance of plants to enhanced ultraviolet-B (UV-B) radiation, Isatis indigotica Fort. seeds were subjected to microwave radiation for 8 s (wavelength 125 mm, power density 1.26 mW mm−2, 2450 MHz). Afterwards they were cultivated in plastic pots in an artificial-glass greenhouse maintained at 25°C, 70% relative humidity, and 400 μmol mol−1 CO2, under visible-light conditions of 1500 μmol m−2 s−1 for 8 h day−1. When the seedlings were 10 days old, they were subjected to 10.08 kJ m−2 UV-B (PAR: 220 μmol m−2 s−1) radiation for 8 days. Changes in a number of physiological and biochemical characteristics and in the thermal decomposition enthalpy of biomass were measured and used as indicators of the protective capacity of microwave radiation in this experiment. Our results revealed that microwave pretreatment of seeds enhanced UV-B stress resistance in the seedlings by decreasing the concentration of malondialdehyde (MDA) and increasing the concentration of ascorbic acid (AsA) and UV-B–absorbing compounds, increasing the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and increasing the energy accumulation of photosynthesis. All these results suggest that microwave radiation enhances plant metabolism and results in increased UV-B stress resistance. This is the first investigation reporting the use of microwave pretreatment to protect the cells of Isatis indigotica from UV-B-induced lesions.

Exposure of the endangered golden monkey (Rhinopithecus roxellana) to heavy metals: a comparison of wild and captive animals

Golden monkeys are endemic to China and of high conservation concern. Conservation strategies include captive breeding, but the success of captive breeding programs may be being compromised by environmental pollution. Heavy metal exposure of wild and captive golden monkeys living in the Qinling Mountains was assessed by measuring fecal metal concentrations (As, Cd, Cr, Co, Cu, Mn, Hg, Ni, Pb, and Zn). Captive monkeys were exposed to higher concentrations of As, Hg, Pb, and Cr than monkeys living in the wild, while high background levels of Mn led to high exposure of wild monkeys. Seasonal variations in metal exposures were detected for both wild and captive monkeys; possible reasons being seasonal changes in either diet (wild monkeys) or metal content of food (captive monkeys). Coal combustion, waste incineration, and traffic-related activities were identified as possible sources of heavy metals exposure for captive animals. Efforts to conserve this endangered primate are potentially compromised by metal pollutants derived from increasing anthropogenic activities. Providing captive animals with uncontaminated food and relocating captive breeding centers away from sources of pollution will reduce pollutant exposure; but ultimately, there is a need to improve environmental quality by controlling pollutants at source.

Conservation efforts of captive golden takin (Budorcas taxicolor bedfordi) are potentially compromised by the elevated chemical elements exposure

Chemical elements exposure of endangered golden takins (Budorcas taxicolor bedfordi) living in the Qinling Mountains and in a captive breeding center was assessed by analyzing fecal samples. Concentrations of As, Co, Cr, Cu, Ni and Se were significantly higher in the feces of captive golden takins than the wild. There was no significant difference in the fecal concentrations of Cd, Mn, Hg, Pb or Zn for wild and captive animals. The element concentration of fecal samples collected from captive animals varied seasonally, with concentrations being lowest in spring and highest in winter and/or autumn. The food provided to captive animals varied both in the composition and the concentration of element present. Consumptions of feedstuff and additional foods such as D. sanguinalis and A. mangostanus for the captive golden takins were identified as the possible sources of chemical element exposure. The estimations of dietary intake of most elements by captive takins were below the oral reference dose, except for As and Pb, indicating that As and Pb were the key components which contributed to the potential non-carcinogenic risk for captive golden takins. In conclusion, captive golden takins were exposed to higher concentrations of chemical elements compared with the wild, which were likely due to their dietary difference. Conservation efforts of captive golden takin are potentially compromised by the elevated chemical element exposure and effort should focus on providing uncontaminated food for captive animals.

Atmospheric deposition exposes pandas to toxic pollutants

The giant panda (Ailuropoda melanoleuca) is one of the most endangered animals in the world, and it is recognized worldwide as a symbol for conservation. A previous study showed that wild and captive pandas were exposed to toxins in their diet of bamboo, but the ultimate origin of these toxins is unknown. Here we show that atmospheric deposition is the origin of heavy metals and persistent organic pollutants (POPs) in the diets of captive and wild Qinling giant pandas. Atmospheric deposition averaged 115 and 49 g⋅m−2⋅yr−1 at China’s Shaanxi Wild Animal Research Center (SWARC) and Foping National Nature Reserve (FNNR), respectively. Atmospheric deposition of heavy metals (As, Cd, Cr, Pb, Hg, Co, Cu, Zn, Mn and Ni) and POPs at SWARC was higher than at FNNR. Soil concentrations of the aforementioned heavy metals other than As and Zn also were significantly higher at SWARC than at FNNR. We conclude that efforts to conserve the Qinling subspecies of panda may be compromised by air pollution attendant to China’s economic development. Improvement of air quality and reductions of toxic emissions are urgently required to protect China’s iconic species.

Environmental toxicants impair liver and kidney function and sperm quality of captive pandas

Captive pandas are exposed to higher concentrations of environmental toxins in their food source and from atmospheric pollution than wild pandas. Moreover, the Qinling panda subspecies had significantly higher concentrations of toxic chemicals in its feces. To determine whether these toxicants also accumulate in pandas blood and impair its health, concentrations of persistent organic pollutants (POPs) and heavy metals were measured in blood samples. Four heavy metals (As, Cd, Cr and Pb), PCDD/Fs and PCBs were detected in blood drawn from captive Qinling pandas. Time spent in captivity was a better predictor of toxicant concentration accumulation than was panda age. More than 50% of the studied pandas were outside the normal levels for 11 health parameters, and five (ALT, LDH, Ca, Cl, TB) of the 11 parameters classified as abnormal were correlated with blood pollutant concentrations. The proportion of live sperm was significantly lower and the aberrance ratio of sperm was significantly greater for captive pandas than for wild ones. A short-term solution to reduce the health impacts of pollution and toxicant exposure of Qinling pandas is to relocate breeding centers to less contaminated areas and to strictly control the quality of their food provided. A longer term solution depends on improving air quality by reducing toxic emissions.

Establish a special conservation zone for the captive giant panda

ABSTRACT The giant panda (Ailuropoda melanoleuca) is recognized worldwide as an icon for wildlife conservation. Since the introduction in 1992 of reliable methods for artificial insemination, the population of captive pandas has grown to approximately 350 individuals in 2013. However, captive panda populations are harmed by environmental pollution, diseases transmitted from domestic animals, and other anthropologenic activities. Although the Chinese government has proposed the creation of a Giant Panda National Park, there are at least three reasons that suggest that it is premature to reintroduce captive pandas into this proposed national park. First, habitat fragmentation remains the greatest threat to survival of giant pandas; second, most captive pandas are hybrids of the Sichuan and Qinling subspecies and release of hybrids may lead to further introgression between the two subspecies; and third, captive pandas may be competitively inferior to wild pandas in the region, and may not survive fights for food or mates. As an alternative, we suggest establishing a special conservation zone in the Shennongjia National Nature Reserve for wild training of captive pandas prior to their reintroduction into the National Park.