Effects of CuSO4 and Uniconazole on Mature Embryo Culture in Japonica Rice

In order to establish the system of high frequency plant regeneration for japonica rice mature embryos, the effects of different concentrations of CuSO4 and uniconazole on in vitro culture of mature embryos were studied using three rice cultivars of Kongyu 131, Longjing 24, and Dongnong 425 as test materials. The results showed that callus induction and differentiation of japonica rice mature embryos were apparently improved on the medium with 10-15 μmol·L-1 CuSO4 and 0.50-1.00 mg·L-1 uniconazole. Induction and differentiation rates of different genotype rice mature embryos displayed different sensitivities to CuSO4 and uniconazole. For the callus induction frequency of three varieties, the optimal concentration of CuSO4 was 15.0 mol·L-1. When the concentration of CuSO4 was 15 μmol·L-1, the plantlet differentiation rates of Kongyu 131 and Dongnong 425 got to the highest, while the concentration of CuSO4 was 10 μmol·L-1 for Longjing 24. For the callus induction and plantlet differentiation rates of Kongyu 131 and Dongnong 425, the ideal concentration of uniconazole was 0.50 mg·L-1 and for Longjing 24 was 1.00 mg·L-1.     

Effects of sodium benzoate on growth and physiological characteristics of wheat seedlings under compound heavy metal stress

In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg~(–1) of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2–4 g L~(–1) sodium benzoate significantly increased(P0.01) chlorophyll content and chlorophyll fluorescence parameters F_v/F_m and F_v/F_o of wheat, compared to the control(water treatment). Further analysis showed that application of 2–4 g L~(–1) sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(6 g L~(–1)) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97–3.12 g L~(–1)(2016) and 1.58–3.27 g L~(–1)(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L~(–1)(2016) or 3.02 g L~(–1)(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2–4 g L~(–1)) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.     

Implications of step-chilling on meat color investigated using proteome analysis of the sarcoplasmic protein fraction of beef longissimus lumborum muscle

In order to improve beef color and color stability,step-chilling(SC)was applied on excised bovine longissimus lumborum muscle,with chilling starting at 0–4℃ for 5 h,then holding the temperature at 12–18℃ for 6 h,followed by 0–4℃ again until 24 h post-mortem.pH and temperature were measured during rigor on SC loins as well as those subjected to routine chilling(RC,0–4℃,till 24 h post-mortem).Color L*,a*,b*values,metmyoglobin(MetM b)content,MetM b reducing ability(MRA)and NADH content were determined on samples aged for 1,7,and 14 d.Sarcoplasmic proteome analysis was only conducted on d 1 samples.The results showed muscles subjected to SC maintained a temperature at around 15℃ for 5 to 10 h post-mortem,and exhibited a slow temperature decline,but rapid pH decline.Beef steaks treated with SC had higher L*,a*,b* and chroma values than those of RC samples at 1 and 7 d chilled storage(0–4℃),while showing no significant difference for a*,b* and chroma values at d 14.The SC samples also exhibited a lower relative content of surface MetM b,higher MRA and NADH content,compared with RC beef steaks during storage,indicating the SC-treated beef showed an improved color stability.Eleven differential protein spots/nine proteins were identified by two-dimensional gel electrophoresis and mass spectrometry,and those proteins were mainly involved in redox,chaperone binding,metabolic and peroxidase activity.Oxidoreductases play a role in decreasing the oxidation-induced myoglobin oxidation and benefiting the production of NADH,and finally improving the colour of beef.Of these,pyruvate dehydrogenase E1 component subunit beta showed a positive correlation with color L*,a*,b*values and accounted for more than 60% of the variation in color values;this protein can be considered as a potential beef color biomarker.The present study provided valuable information for studies on the molecular mechanism of color improvement from step-chilling,as well as for identifying markers associated with beef color.     

Effects of uniconazole with or without micronutrient on the lignin biosynthesis,lodging resistance,and winter wheat production in semiarid regions

Lodging stress results in grain yield and quality reduction in wheat. Uniconazole, a potential plant growth regulator significantly enhances lignin biosynthesis and thus provides mechanical strength to plants in order to cope with lodging stress. A field study was conducted during the 2015–2016 and 2016–2017 growing seasons, to investigate the effects of uniconazole sole application or with micronutrient on the lignin biosynthesis, lodging resistance, and production of winter wheat. In the first experiment, uniconazole at concentrations of 0(CK), 15(US1), 30(US2), and 45(US3) mg L~(-1)was applied as sole seed soaking, while in the second experiment with manganese(Mn) at concentration of 0.06 g L~(-1)Mn, 0.06 g L~(-1)Mn+ 15 mg L~(-1)uniconazole(UMS1), 0.06 g L~(-1)Mn+30 mg L~(-1)uniconazole(UMS2), and 0.06 g L~(-1)Mn+45 mg L~(-1)uniconazole(UMS3), respectively. Uniconazole sole application or with micronutrient significantly increased the lignin content by improving the lignin-related enzyme activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, tyrosine ammonialyase, and peroxidase, ameliorating basal internode characteristics, and breaking strength. The spike length, spike diameter, spikes/plant, weight/spike, yield/spike, and grain yield increased and then decreased with uniconazole application at a higher concentration, where their maximum values were recorded with UMS2 and US2 treatments. The lignin accumulation was positively correlated with lignin-related enzyme activities and breaking strength while, negatively correlated with lodging rate. Uniconazole significantly improved the lignin biosynthesis, lodging resistance, and grain yield of winter wheat and the treatments which showed the greatest effects were uniconazole seed soaking with micronutrient at a concentration of 30 mg L~(-1)and 0.06 g L~(-1), and uniconazole sole seed soaking at a concentration of 30 mg L~(-1).     

Screening of Optimal Differentiation Medium toLonicera edulis

An excellent Lonicera edulis strain, L1-8 that was bred by Northeast Institute of Geography and Agro-ecology, Chinese Academy of Sciences, was used as material in this research. The axillary buds of its dormant branches were used as explants. A fourfactor and four-level orthogonal test was designed in order to choose the best differentiation medium for providing the technical support of Lonicera edulis micropropagation. The results showed that the culture medium and concentration of 6-BA were the main factors, and the best differentiation condition was MS culture medium containing 2.0 mg · L-1 6-BA, 0.3 mg · L-1 IBA and 1.5 mg · L-1 GA3.     

Regulation of Foliar Application DCPTA on Growth and Development of Maize Seedling Leaves in Heilongjiang Province

DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.     

Nitrogen Removal Improvement by Adding Peat in Deep Soil of Subsurface Wastewater Infiltration System

In order to enhance the nitrogen removal, a subsurface wastewater infiltration system (SWIS) was improved by adding peat in deep soil as carbon source for denitrification process. The effects of addition of carbon source in the underpart of the SWIS on nitrogen removal at different influents (with the total nitrogen (TN) concentration 40 and 80 mg L⁻¹, respectively) were investigated by soil column simulating experiments. When the relatively light pollution influent with 40 mg L⁻¹ TN was used, the average concentrations of NO₃⁻-N and TN in effluents were (4.69±0.235), (6.18±0.079) mg L⁻¹, respectively, decreased by 32 and 30.8% than the control; the NO₃⁻-N concentration of all effluents was below the maximum contaminant level of 10 mg L⁻¹; as high as 92.67% of the TN removal efficiency was achieved. When relatively heavy pollution influent with 80 mg L⁻¹ TN was used, the average concentrations of NO₃⁻-N and TN in effluents were (10.2±0.265), (12.5±0.148) mg L⁻¹ respectively, decreased by 20 and 21.2% than the control; the NO₃⁻-N concentration of all effluents met the grade III of the national quality standard for ground water of China (GB/T 14848-1993) with the values less than 20 mg L⁻¹; the TN removal efficiency of 94.1% was achieved. In summary, adding peat in the underpart of the SWIS significantly decreased TN and NO₃⁻-N concentration in effluents and the nitrogen removal efficiency improved significantly.     

Quantifying key model parameters for wheat leaf gas exchange under different environmental conditions

The maximum carboxylation rate of Rubisco(V_(cmax)) and maximum rate of electron transport(J_(max)) for the biochemical photosynthetic model, and the slope(m) of the Ball-Berry stomatal conductance model influence gas exchange estimates between plants and the atmosphere. However, there is limited data on the variation of these three parameters for annual crops under different environmental conditions. Gas exchange measurements of light and CO_2 response curves on leaves of winter wheat and spring wheat were conducted during the wheat growing season under different environmental conditions. There were no significant differences for V_(cmax), J_(max) or m between the two wheat types. The seasonal variation of V_(cmax), J_(max) and m for spring wheat was not pronounced, except a rapid decrease for V_(cmax) and J_(max) at the end of growing season. V_(cmax) and J_(max) show no significant changes during soil drying until light saturated stomatal conductance(gssat) was smaller than 0.15 mol m~(–2) s~(–1). Meanwhile, there was a significant difference in m during two different water supply conditions separated by gssat at 0.15 mol m~(–2) s~(–1). Furthermore, the misestimation of V_(cmax) and J_(max) had great impacts on the net photosynthesis rate simulation, whereas, the underestimation of m resulted in underestimated stomatal conductance and transpiration rate and an overestimation of water use efficiency. Our work demonstrates that the impact of severe environmental conditions and specific growing stages on the variation of key model parameters should be taken into account for simulating gas exchange between plants and the atmosphere. Meanwhile, modification of m and V_(cmax)(and J_(max)) successively based on water stress severity might be adopted to simulate gas exchange between plants and the atmosphere under drought.     

Assessment of Phosphorus Levels in Small Ruminants as Affected by Summer and Winter

An experiment was carried out to assess the phosphorus status of free grazing goats at Faisalabad,Pakistan.Samples were collected fortnightly during summer and winter seasons of 2010 from soil and plants.The highest(118±0.54 mg·kg-1)levels of feces phosphorus were recorded in lactating goats during winter and(9.87±0.99 mg·kg-1)in urine of male during winter.Similarly maximum(71.0±0.88 mg·kg-1)phosphorus concentration was observed in the plasma of lactating animals.Milk contained(31.0±0.36)mg·L-1 in winter while during the months of summer the highest values recorded in forages,soils,canal and tube well waters were(755±1.98)mg·kg-1,(785±4.98)mg·kg-1,(0.97±8.78)mg·L-1 and(4.12±0.55)mg·L-1,respectively.It was revealed from the current results that fecal matter,forage,milk,tube well and canal water contained lower amounts of P,while P levels in blood plasma was found within the critical limits.Therefore,phosphorus supplementations were required in the area under experimentation to meet the requirements of the animals for their normal growth.     

Arsenic Distribution,Species, and Its Effect on Maize Growth Treated with Arsenate

A pot experiment was conducted to investigate the effect of different arsenic (As) levels on maize (Zea mays L.) growth and As accumulation and species in different parts of maize plants, as a guideline for production of maize in As-polluted areas with the objective of preventing As from entering the food chain, and improving understanding of the mechanisms of effect of As on plant. Zhengdan 958 was grown at five As levels added to soil (0, 12.5, 25, 50, and 100 mg kg⁻¹ As). As concentration in maize tissues increased in the order of grain<stalk<leaf ≪root. The As concentration in maize grain exceeded the maximum permissible concentration of 0.7 mg kg⁻¹ in China at levels of 50 and 100 mg kg⁻¹. As species were presented in root, stalk, and grain, but organic As was the major As species identified in the grain. Maize plants were able to reduce arsenate to arsenite. Low As levels of 12.5 and 25 mg kg⁻¹ improved maize growth and grain nutrition quality, while high levels of As 50 or 100 mg kg⁻¹ inhibited them. Yield reduction at high As levels resulted mainly from reduced ear length, kernel number per row, and kernel weight.     

The mitigation effects of exogenous dopamine on low nitrogen stress in Malus hupehensis

Dopamine plays numerous physiological roles in plants. We explored its role in the regulation of growth, nutrient absorption, and response to nitrogen (N) deficiency in Malus hupehensis Rehd. Under low N condition, plant growth slowed, and the net photosynthetic rates, chlorophyll contents, and maximal quantum yield of PSII (F_v/F_m) decreased significantly. However, the application of 100 μmol L⁻¹ exogenous dopamine significantly reduced the inhibition of low N stress on plant growth. In addition to modifying root system architecture under low N supply, exogenous dopamine also changed the uptake, transport, and distribution of N, P, and K. Furthermore, exogenous dopamine enhances the tolerance to low nitrogen stress by increasing the activity of enzymes (nitrate reductase, nitrite reductase, glutamic acid synthase and glutamine synthetase) involved in N metabolism. We also found that exogenous dopamine promoted the expression of ethylene signaling genes (ERF1, ERF2, EIL1, ERS2, ETR1, and EIN4) under low N stress. Therefore, we hypothesized that ethylene might be involved in dopamine response to low N stress in M. hupehensis. Our results suggest that exogenous dopamine can mitigate low N stress by regulating the absorption of mineral nutrients, possibly through the regulation of the ethylene signaling pathway.     

Interactive Effect of GA3, N and P Ameliorate Growth,Seed and Fibre Yield by Enhancing Photosynthetic Capacity and Carbonic Anhydrase Activity of Linseed: A Dual Purpose Crop

Linseed (Linum usitatissimum L.) is an important dual-purpose, industrial crop. Its seeds are used for the extraction of oil and stem for fibres. However, the production of linseed is not going parallel with the increasing demand of its products. The present work was carried out with an aim to find out whether exogenous application of gibberellic acid (GA₃) with or without graded levels of nitrogen (N) and phosphorus (P) could improve the performance of three linseed genotypes Parvati, Shekhar and Shubhra together with minimizing the costly fertilizer input and losses. Four combinations of N and P, viz., 0 mg N+0 mg P kg^?1 soil (N₀P₀), N_13.4P_4.46, N_26.8P_8.94 and N_40.2P_13.4 were constituted. Half dose of each combination was applied basally at the time of sowing and remaining half dose was given at 40 d after sowing (DAS) as foliar spray along with 10^?6 mol L^?1 GA₃. Prior to sowing, the seeds of each linseed genotype were grouped in to two, one group of seeds was soaked in 0 mol L^?1 GA₃ (control) and the other group was soaked in 10^?6 M GA₃ solution, each for 8 hours. Treatments were comprised of (i) 0 mol L^?1 GA₃+N₀P₀ (T₀, control), (ii) 10^?6 mol L^?1 GA₃ + N₁₃₄P₄₄₆ (T₁), (iii) 10^?6 mol L^?1 GA₃+N_26.8P_8.94 (T₂) and (iv) 10^?6 mol L^?1 GA₃+N_40.2P_13.4 (T₃). The crop performance was assessed in terms of growth, physiological and biochemical parameters at 60 and 75 DAS and yield attributes at harvest (175 DAS). The results showed a parallel increase in most of the parameters with increasing levels of N and P. However, application of 10^?6 mol L^?1 GA₃ in association with N_26.8P_8.94 proved best, it enhanced seed yield, oil yield and fibre yield by 83.3, 97.3 and 78.7%, respectively accompanied with increase in net photosynthetic rate, carbonic anhydrase activity and dry matter accumulation. Among the genotypes tested, Shubhra performed best, while Parvati the least for most of the parameters studied. Thus, combined application of 10^?6 mol L^?1 GA₃ plus N_26.8P_8.94 proved best and can be recommended to exploit the linseed as a dual-purpose crop for good yield of seed and fibre.     

Attraction of bruchid beetles Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) to host plant volatiles

Host-plant volatiles play an important role as cues for herbivores in search of resources, mates and oviposition sites in complex environments. Plant volatile-based attractants can be developed for pest monitoring and control. Previously, we indicated that mated female adults of Callosobruchus chinensis showed choice preference behavior toward 2-hexenal and benzaldehyde. Our objective here was to investigate the synergistic effect of host-derived attractive volatiles in attracting C. chinensis under laboratory and field conditions in Shanxi Province, China. We hypothesized that the ratio and concentration of volatiles derived from Vigna radiata play critical roles for C. chinensis in locating this host. Therefore, we collected and identified the volatiles of mungbean by using headspace collection and GC-MS. The effectiveness of different ratios and concentrations of two compounds (2-hexenal and benzaldehyde) that elicit C. chinensis searching behavior were examined in Y-tube olfactometer assays. The combination of 300 μg μL⁻¹ 2-hexenal and 180 μg μL⁻¹ benzaldehyde loadings exhibited a synergistic effect on attracting C. chinensis (82.35%). Compared to control traps, the adults were significantly attracted to traps baited with blends, and more attraction to females than males was found for blend traps in the field experiments. Our results suggest that blends of this specific concentration and ratio of benzaldehyde and 2-hexenal can be used in traps as attractants for C. chinensis monitoring and control in the field.     

The chemical treatments combined with antagonistic yeast control anthracnose and maintain the quality of postharvest mango fruit

During the storage and transportation of the mango fruit, the major source of disease is anthracnose, caused by the fungus Colletotrichum gloeosporioides. The objective of this study is to find an appropriate method that not only reduces mango decay but also maintains its postharvest quality. The effects of chemicals, the use of the yeast species Metschnikowia pulcherrima and their combination on storage quality, focusing on the enzyme activity related to disease of Tainong mangos was studied. By immersing the mangoes in M. pulcherrima suspension(1.0×10~8 cfu mL~(–1)), salicylic acid(SA) solution(50 mg L~(–1)) or calcium chloride(CaCl_2) solution(1.0 g L~(–1)), the lesion expansion and decay of the mango fruit caused by C. gloeosporioides could be significantly delayed. These treatments also delayed the changes in quality traits(a~* value, firmness, contents of total soluble solids(TSS) and vitamin C(Vc), while the activities of anti-disease enzymes such as polyphenol oxidase(PPO), phenylalanine ammonia lyase(PAL), chitinase(CHT) and β-1,3-glucanase(GUN) were enhanced as compared to the control treatment. Furthermore, the combination of SA solution, CaCl_2 solution and M. pulcherrima suspension presented an additive effect, increasing the efficacy in controlling the disease and maintaining the storage quality of mango fruits. Taken together, our data suggest that the integration of chemical treatments combined with M. pulcherrima could be an alternative to the use of fungicides in postharvest treatment of the mango fruit, specifically for improving storage quality as well as the control of the anthracnose.     

The positive function of selenium supplementation on reducing nitrate accumulation in hydroponic lettuce (Lactuca sativa L.)

High nitrate(NO_3~- ) in vegetables, especially in leaf vegetables poses threaten to human health. Selenium(Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses. However, the influence of exogenous Se on NO_3~- accumulation in hydroponic vegetables is still not clear. In the present study, hydroponic lettuce plants were subjected to six different concentrations(0, 0.1, 0.5, 5, 10 and 50 μmol L–1) of Se as Na2 Se O3. The effects of Se on NO_3~- content, plant growth, and photosynthetic capacity of lettuce(Lactuca sativa L.) were investigated. The results showed that exogenous Se positively decreased NO_3~- content and this effect was concentration-dependent. The lowest NO_3~- content was obtained under 0.5 μmol L–1 Se treatment. The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate(Pn), stomatal conductance(Cs) and the transpiration efficiency(Tr) of lettuce. The transportation and assimilation of NO_3~- and activities of nitrogen metabolism enzymes in lettuce were also analysed. The NO_3~- efflux in the lettuce roots was markedly increased, but the efflux of NO_3~- from the root to the shoot was decreased after treated with exogenous Se. Moreover, Se application stimulated NO_3~- assimilation by enhancing nitrate reductase(NR), nitrite reductase(Ni R), glutamine synthetase(GS) and glutamate synthase enzyme(GOGAT) activities. These results provide direct evidence that exogenous Se shows positive function on decreasing NO_3~- accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce. We suggested that 0.5 μmol L–1 Se can be used to reduce NO_3~- content and increase hydroponic lettuce yield.     

Response of Osmotic Adjustment of Lactobacillus bulgaricus to NaCl Stress

Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of ...     

Putrescine Plays a Positive Role in Salt-Tolerance Mechanisms by Reducing Oxidative Damage in Roots of Vegetable Soybean

Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put （10 mmol L＂） and its biosynthetic inhibitor D-arginine （D-Arg） （0.5 mmol L-1） were added to nutrient solution when vegetable soybean （Glycine max L. cv. Huning 95-1） seedlings were exposed to 100 mmol L^-11 sodium chloride （NaCl）. The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine （Spd） and spermine （Spm） were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase （ADC）, S-adenosylmethionine decarboxylase （SAMDC）, diamine oxidase （DAO）, and polyamine oxidase （PAO） were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species （ROS） production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.