Copper nanoparticles together with cold atmospheric plasma improves the growth and physiological indices of Dracocephalum moldavica in hydroponic system

This experiment was conducted to investigate the effect of copper nanoparticles and cold atmospheric plasma on growth and physiological indices of Dracocephalum moldavica herbal plant under hydroponic culture conditions. The factors investigated in this experiment were copper nanoparticles at four levels of zero (control), 25, 50, and 75 ppm and cold atmospheric plas-ma at three times of zero (control), 20, and 30 seconds. The results showed that application of cold atmospheric plasma led to an increase in the shoot height, root length, shoot dry weight, root dry weight, leaf area, chlorophyll a, chlorophyll b, total chlorophyll, soluble leaf protein; it also decreased proline content. In addition, there was no significant difference between cold atmospheric plasma at the two durations of 20 and 30 seconds. Moreover, compared with the control and non-nanoparticle copper treatments, the use of copper nanoparticles improved the measured indices; accordingly, when making its greatest effect, the use of copper nanoparticles led to 27.77% increase in shoot height, 73.76% in root length, 67.98% in shoot dry weight, 87.67% in root dry weight, 22.83% in leaf area, 76.19% in soluble leaf protein in treatment with 25 ppm of copper and 39.42%, 50%, and 42.36% increase in chlorophyll a, chlorophyll b, total chlorophyll, respectively in treatment with 50 ppm of copper nanoparticles. Considering the obtained results, it can be concluded that the use of 25 ppm of copper nanoparticles (due to the application of nanoparticle instead of non-nanoparticle copper) within 20 seconds of cold atmospheric plasma improves the growth and physiological indices of D. moldavica herbal plant under hydroponic culture conditions.

Response of Rice Nitrogen Physiology to High Nighttime Temperature during Vegetative Stage

The effects of night temperature on plant morphology and nitrogen accumulation were examined in rice (Oryza sativaL.) during vegetative growth. The results showed that the shoot biomass of the plants was greater at 27°C (high nighttime temperature, HNT) than at 22°C (CK). However, the increase in both shoot and root biomasses was not significant under 10 mg N/L. The shoot nitrogen concentrations were 16.1% and 16.7% higher in HNT than in CK under 160 and 40 mg N/L. These results suggest that plant N uptake was enhanced under HNT; however, the positive effect might be limited by the N status of the plants. In addition, leaf area, plant height, root maximum length, root and shoot nitrogen concentrations, soluble leaf protein content, and soluble leaf carbohydrate content were greater in HNT than in CK under 40 and 160 mg N/L, while fresh root volume, root number, and the content of free amino acid in leaf were not significantly different between HNT and CK regardless of nitrogen levels. Moreover, leaf GS activity under HNT was increased at 160 mg N/L compared with that under CK, which might partly explain the positive effect of HNT on soluble protein and carbohydrate content.

Protection of leaf protein of lucerne (Medicago sativa L.) against degradation in the rumen by treatment with formaldehyde and glutaraldehyde

SUMMARYAqueous glutaraldehyde, in the presence of wetting agents Tween-20 or Haemosol, reacted with fresh cut lucerne (Medicago sativa L.), complete reaction being obtained with about 7·2 g (72 mmol)/kg herbage, or 18g/100g crude protein. Reaction with 25% w/v aqueous glutaraldehyde sprayed on to fresh lucerne was rapid, and at the rate of 66 mmol/kg lucerne, all aldehyde had reacted in 3 h and about 60% of the soluble leaf protein became insoluble. Formaldehyde at twice the molar concentration of glutaraldehyde was absorbed rapidly, but a longer time, up to 24 h, was required for the protein to become insoluble. Treatments with 22, 44 and 66 mmol glutaraldehyde/kg lucerne, and 44, 88 and 132 mmol formaldehyde/kg showed that reaction with leaf protein was approximately proportional to the amount of aldehyde. A major effect on the leaf cells was the fixation of chloroplasts, and intact fixed chloroplasts were isolated from treated lucerne with high protein: chlorophyll ratios of 5·8:1 to 9·5:1.Two varieties of lucerne, Kabul and Europe, pot-grown in a controlled environment cabinet, reacted rapidly when sprayed with glutaraldehyde and in 3 h soluble leaf protein was reduced from 30 to 16–17% of the total N. The plants rapidly lost water and the dry matter of the leaves rose to 42% for Kabul and 45% for Europe in 24 h. Stems showed little effect. Field spraying of lucerne with glutaraldehyde similarly fixed soluble leaf protein and caused desiccation of the leaves, rising to 47–50% D. M. in 3 days. The stems were little affected and subsequent regrowth of the plants was not inhibited.Feeding glutaraldehyde- and formaldehyde-sprayed lucerne to rumen-fistulated cattle showed that release of soluble leaf protein into the rumen fluid was greatly reduced, mean values being 40 and 43% respectively of the values obtained when control lucerne was fed. Mean ammonia concentrations were similarly reduced to 49 and 33% of the control values. Formaldehyde-treated lucerne, even after reaction for several days, frequently showed toxic effects on rumen micro-organisms, particularly protozoa. Glutaraldehyde reacted more rapidly with herbage and no toxic effects were observed. Both glutaraldehyde- and formaldehyde-treated lucerne were highly palatable to cattle.

Ruminal digestion of chloroplasts and the protection of protein by glutaraldehyde treatment

SummaryChloroplasts, 50–80% intact, were prepared from kale (Brassica oleracea L. var. Marrowstem) by rapid homogenization (3·5 sec) of deveined leaves into partially frozen buffer pH 7·4 made 0·4 M with sucrose, and separated by differential centrifugation. Chloroplasts from 10 kg leaves were administered to the rumen of a sheep and the degradation followed by analysis of the rumen fluid which was collected continuously. Particulate matter of the rumen fluid was separated on discontinuous sucrose density gradients, 8 ml each of 35, 46, 50, 65 and 75% (w/v), centrifuging at 300 g for 1 h at + 2 °C. Chloroplasts were rapidly ingested by entodiniomorphid protozoa and digested with no detectable increase in soluble nitrogen in the rumen fluid. No net production of ammonia occurred but δ-amino-valeric acid increased indicating that amino acid transformations had occurred. Chlorophyll in the ingested chloroplasts was rapidly degraded with a half-life of 50–60 min. In contrast a similar amount of soluble casein added to the rumen degraded with a half-life of 13–14 min with large increase in soluble nitrogen consisting of peptides, amino acids, ammonia and δ-amino-valeric acid. Glutaraldehyde treated chloroplasts were also ingested by protozoa, chlorophyll was rapidly degraded but there was no increase in the soluble nitrogen of the rumen fluid, including ammonia and δ-amino-valeric acid. Water disrupted chloroplasts released soluble protein and in the rumen behaved like casein, producing high proportions of ammonia and δ-amino-valeric acid. The significance of these experiments in the protection of soluble leaf protein from degradation in the rumen of pasture-fed animals is discussed.