Changes in the composition and content of lipids in the leaves of radish plants of different magnetic orientation induced by weak permanent magnetic field

The effect of weak permanent horizontal magnetic field (PMF) with the intensity of 403 A/m on the composition and content of polar and neutral lipids and their constituent FAs was investigated in the leaves of radish plants (Raphanus sativus L., var. radicula D.C.), cv. Rozovo-krasnyi s belym konchikom, which belong to two major types of magnetic orientation (TMO): North-South (NS) and West-East (WE), with the planes of the root grooves oriented along and across the magnetic meridian, respectively. In spring, PMF reduced the level of total lipids in the NS plants and elevated it in the WE plants; in autumn, the content of total lipids in the NS plants increased in the NS plants and decreased in the WE plants. In spring, the ratio between phospholipids and sterols, which indirectly points to enhanced fluidity of membrane lipid bilayer, increased in the plants of both TMOs, while in autumn, it increased only in the NS plants. In the control plants, the relative content of unsaturated FAs, including linolenic and linoleic acids, was greater in the WE plants than in the NS plants. PMF elevated the content of FAs in the leaves of the NS plants and did not affect their level in the WE plants. It was concluded that weak horizontal PMF differently (and sometimes oppositely) affected the content of lipids in the leaves of the NS and WE radish plants, apparently due to their different sensitivity to the effect of the magnetic field associated with their physiological status.     

Effect of alternating magnetic field on ontogenesis and morphophysiological characteristics of radish plants of different magnetic orientation

Effect of weak horizontal alternating magnetic field (AMF) with a frequency of 50 Hz and intensity of 400 A/m on seed formation and morphophysiological characteristics was investigated in radish (Raphanus sativus L.) plants of major types of magnetic orientation (TMO): North–South (NS) and West–East (WE). AMF retarded the passage through all the stages of ontogenesis; as compared with control material, the next leaves emerged slower, and the transition to formation of flower-bearing stems, budding, flowering, and production of pods and mature seeds was delayed. In plants of NS TMO exposed to AMP, the number of pods and seeds and the weight of seeds decreased, while these characteristics rose in WE TMO. AMF acted as an environmental factor differentiating plants’ response depending on their type of magnetic orientation. Dissimilar response to the magnetic field is associated with their physiological status.     

Lipid composition and content in the seeds of radish plants of different magnetic orientation grown in weak permanent magnetic field

The content and composition of lipids were studied in the seeds of radish plants (Raphanus sativus L. var. radicula D.C., cv. Rosovo-krashyi s belym konchikom) grown from “seed to seed” in 2008 and 2009 in the greenhouse of the Institute of Plant Physiology in a permanent horizontal magnetic field (PMF) of Helmholz coils with the strength of ～400 A/m, in soil culture, at natural day length, and a temperature changing during the day. PMF suppressed all stages of radish plant development, from the appearance of alternative leaves to the formation of pods and mature seeds. In plants of the North-South magnetically oriented type (NS MOT), PMF reduced the number and weight of seeds; in the West-East magnetically oriented type (WEMOT), the number of seeds was reduced but their weights increased. In the seeds of the first generation of NS MOT, the total lipid content was higher than in the seeds of WE MOT. The amount of polar lipids in the seeds of NS MOT increased, whereas in the seeds of WE MOT it decreased or remained unchanged as compared with control. The content of neutral lipids reduced in both plant types. The strongest changes in the fatty acid composition of lipids with the highest content of unsaturated fatty acids were observed in the seeds of WE MOT in 2008. The weak PMF-induced differences in the changes of lipid composition and content in the seeds of different MOTs were evidently determined by seed sensitivity to the direction of field action. It is suggested that the occurrence of different MOTs increases the tolerance of plant population to unfavorable environmental factors, thus affecting its survival.     

Effect of Choline Chloride on the Lipid Content and Composition in the Leaves of Principal Magnetically-Oriented Radish Types

The effects of radish seed treatment with choline chloride on the number and weight of leaves, the weight of roots, as well as the content and composition of polar and neutral lipids and their component fatty acids in the leaves of principal magnetically-oriented types (MOTs) of radish (cv. Rosovo-krasnyi s belym konchikom), that is, North–South (NS) and West–East (WE) ones, were investigated. It was shown that seed treatment with 1% choline chloride increased the proportion of WE MOT in plant population. In spring and in autumn, this treatment increased the weight of roots of the NS MOT plants, but did not affect this index in the WE MOT plants. In the spring NS MOT plants, choline chloride treatment did not change the absolute content of polar lipids as compared to the control, but in autumn, this index increased. Meanwhile, in the WE MOT plants, it increased in spring and did not change in autumn. In the spring NS MOT plants, the content of neutral lipids increased, but in the autumn plants, it did not change. At the same time, in the WE MOT plants, this index decreased both in spring and in autumn. Seed treatment with choline chloride resulted in a substantial increase in the total content of phospholipids, in particular, that of phosphatidylcholine and phosphatidylethanolamine, in the NS and WE MOT plants sampled both in spring and in autumn. In addition, the ratio of unsaturated to saturated fatty acids, as well as that of linolenic to linoleic fatty acids, somewhat increased in the NS MOT leaf lipids, but decreased in the WE MOT ones. Presowing treatment of radish seeds with choline chloride variously and sometimes oppositely affected the content and composition in the NS and WE MOT leaf lipids. This seems to be caused by different response of these MOTs to the environmental factors.     

Growth of Green Onions in a Weak Permanent Magnetic Field

Effect of a weak permanent magnetic field (PMF) with a strength of 403 A/m on Allium cepaL. bulb sprouting and leaf growth was investigated. Two onion varieties to produce green onions (cv. Arzamasskii) and bulb onions (cv. Ryazanskii) were examined. In addition, the content of chlorophyll, carbohydrates, and protein in the leaves of the control and PMF-treated plants were determined. The plants of the control group were grown under a natural geomagnetic field. The treatment of onions with PMF accelerated sprouting and extended the length of the fourth leaf in cv. Arzamasskii as much as 40%; the first leaf in cv. Ryazanskii was lengthened by 25% with respect to its length in untreated plants. Exposure to PMF increased the number of sprouts in cv. Ryazanskii and the number of sprout bunches in cv. Arzamasskii. In addition, PMF elevated the total content of chlorophyll and protein, expressed per fresh weight of green onions, but had no effect on the total content of carbohydrates. Conversely, PMF reliably reduced the total content of chlorophyll and protein in cv. Ryazanskii. The temperature increase diminished the effects of PMF.     

The effects of a weak permanent magnetic field on the lipid composition and content in the onion leaves of various ages

We have studied the effects of a weak permanent magnetic field (PMF) with strength of 403 A/m on the composition and content of polar and neutral lipids and the composition of their fatty acids (FAs). The lipids were isolated from the third, fourth, and fifth leaves of onion (Allium cepa L., cv. Arzamasskii) plants, and their composition was determined using TLC and GLC techniques. Plants growth under the conditions of a natural geomagnetic field served as a control. Most intense changes in the lipid content induced by PMF were observed in the fourth onion leaf. The content of total lipids and that of polar lipids (glyco-and phospholipids) changed, whereas the content of neutral lipids either decreased or remained unchanged. The phospholipid/sterol ratio increased, causing an increase in the fluidity of the membrane lipid bilayer. PMF induced an increase in the concentration of linolenic acid and the relative content of total unsaturated FAs. The effects of PMF on the content and composition of lipids in the third and fifth onion leaves were less pronounced, demonstrating differences between the leaves of various ages in their sensitivity to the effects of magnetic field. It is concluded that changes in the weak PMF within the limits of changes in the strength of geomagnetic field in the course of evolution can affect biochemical and physiological processes of plants.     

Impact of weak permanent magnetic field on antioxidant enzyme activities in radish seedlings

The impact of weak permanent magnetic field (PMF) with magnetic flux density of 185–650 μT on activities of antioxidant enzymes in 5-day-old radish (Raphanus sativus L. var. radicula D.C.) seedlings, cv, Rosovo-krasnyi s belym konchikom was demonstrated. In the range of 185–325 μT PMF suppressed superoxide dismutase (SOD) activity in seedling grown in darkness and catalase (CAT) grown in both darkness and light. At the same values of magnetic flux density, all fractions of guaiacol peroxidase were activated and MDA accumulation was enhanced. At the higher values of magnetic flux density, SOD was activated in seedlings grown in darkness and CAT was activated in seedlings grown in both darkness and light. Other indices decreased or remained unchanged. It was concluded that PMF action depends on its intensity: at its low values, antioxidant enzymes are inhibited and at high values — activated.     

Effect of weak constant magnetic field on the composition and content of lipids in radish seedlings at various temperatures

We studied the effects of weak permanent homogenous hirizontal magnetic field (PMF) (400 A/m) on the composition and content of lipids and composition of their fatty acids (FAs) in radish (Raphanus sativus L. var. radicula D.C., cv. Rosovo-krashyi s belym konchikom) seedlings at temperatures of 20 and 10°C. We compared lipid composition and content in seedlings at the phase of developed cotyledons (20°C, 5-day-old, and 10°C, 8-day-old seedlings) under low light and in darkness with the lipid composition and content in dry seeds. The seedlings grown in geomagnetic field (GMF) served as a control. In dry seeds, about 99% of total lipids comprised neutral lipids (NL) and only 1% were polar lipids (PL). Triacylglycerols predominated among NL comprising 93% of total seed lipids. During seed germination, NLs were consumed and PL were produced: the amount of glycolipids increased in control by 3.5–5 times and the amount of phospholipis, by 1.5–2 times.In the light at 20°C, PMF suppressed the formation of PL (by 18%), whereas in darkness, it stimulated it approximately by 80% as compared with control. In the light at 10°C, PMF slightly stimulated PL formation; in darkness, it did not almost affect their synthesis. In all treatments, PMF increased the ratio of phospholipids to sterols by 30–100%. Among FA, PMF exerted the strongest effect on the content of erucic acid: it increased in the light and in darkness at 20°C approximately by 25% and decreased at 10°C in the light by 13%. PMF behaved as a correction factor affecting lipid metabolism on the background of light and temperature action.     

Changes in thiocyanate content in some radish Raphanus sativus L. cultivars during hypocotyl-root growth

Changes in the thiocyanate content in hypocotyl-roots and leaves of radish were observed in a two-year field experiment. Six cultivars were tested: early radish (Rex and Ostergruss Różowa), Japanese radish (Tokinashi and Minowase Summer Cross F₁), and winter radish (Monachijska Biała and Murzynka). A significant diversification in thiocyanate content among cultivars, plant parts, harvest dates and observation years was found. Early cultivars contained the least amount of these compounds, Murzynka — the greatest. The content of thiocyanates in leaves was 3 – 5 times higher than that in hypocotyl-roots. The changes in the thiocyanate content during root growth showed a constant rising tendency in the case of the leaves of all cultivars and the storage organs of Murzynka.     

Physiological studies on salinity VI. Changes in water content and mineral composition of some plants over a range of salinity stresses

Summary Sand culture technique was used to study the effect of irrigation with saline nutrient solutions on the water and mineral elements content of leaves of safflower, sunflower, wheat and radish. Saline culture solutions were prepared by adding NaCl and CaCl₂ to Pfeffer's nutrient solution. The water content of wheat leaves was not affected by salinity, whereas that of leaves of safflower, sunflower and radish was significantly decreased at the high salinity level (6000 ppm) only.Sodium and calcium content of all test plants was generally increased progressively with salinity. The total nitrogen content of safflower and sunflower leaves was significantly increased, whereas that of wheat and radish leaves was almost significantly decreased by salinity. Salinity induced nonsignificant effect on phosphorus content of all test plants. Potassium content of the test plants was significantly reduced by salinity. Magnesium content of safflower and sunflower was significantly decreased by salinity, but the effect was non-significant in case of wheat and radish leaves. re]19760625     

Effects of 2-Chloroethylphosphonic Acid on Growth, Plastid Pigments, and Sucrose Translocation in Radish

2-Chloroethylphosphonic acid (CEPA) caused a significant declinein chlorophyll content of radish plant within 5 d of treatment.Such effects were greater when plants were treated at the two-than at the four-leaf stage. In early treated plants, concentrationof CEPA increasing from 20 mg/1 progressively increased leafweight, while decreasing root (radish) weight. A concentrationof 10 mg/1, applied at the three-leaf stage, increased leafand root weights by 27 and 30 per cent respectively in the cultivar‘Cavalier’. Similar responses were obtained withthe cultivar ‘Cherry Belle’. While Cavalier showeda discrete 10 mg/1 optimum, ‘Cherry Belle’ exhibiteda range of concentrations (10-40 mg/1) optimal for growth. At relatively high concentrations, early application of CEPAcaused inverse changes in sucrose-¹⁴C in the leaves and theroot, so that decreased retention by leaves was accompaniedby increased transport to roots. Low concentrations of CEPAappear promising for growth stimulation in root-crop plants.     

Effects of season-dependent irradiance levels and nitrogen-deficiency on photosynthesis and photoinhibition in field-grown rice (Oryza sativa)

Photoinhibition and acclimation of photosynthesis in rice plants grown under N-sufficient (NS) and N-deficient (ND) field conditions were investigated during the tropical wet (WS) and dry (DS) seasons in the Philippines. Diurnal patterns of CO₂ assimilation were examined. There was a transient peak in CO₂ assimilation in the leaves of the NS plants in the early morning during the DS and the WS, which was not seen in the ND plants in either season. ND leaves had lower Ribulose bisphosphate carboxylase/oxygenase (Rubisco) contents and lower chlorophyll contents. A lowered quantum yield of photosystem II (φPSII) was observed in the ND plants at an intermediate irradiance though no differences between N treatments were seen at high irradiance. Analysis of carotenoids indicated a small increase in the de-epoxidation state of the xanthophyll cycle (DES) at mid-day in the ND leaves compared to NS. Photoinhibition was greater in ND leaves when incident mid-day irradiance was increased by altering the leaf angle. Although Rubisco contents were lower in ND plants, photosynthesis in situ did not decline proportionally. For NS plants, Chlorophyll content, but not Rubisco content, was season-dependent and results are discussed in terms of the interaction between irradiance use and N content of rice leaves.     

Thiocyanate content in relation to the quality features of radish Raphanus sativus L

Relationships between radish thiocyanate content and its dry weight, the content of sugar, protein, fibre, ascorbic acid, some minerals, the incidence of plant shooting, the firmness and pithiness of storage-roots, and the ratio of leaves to storageroot (wt/wt) were investigated. The analysis of linear correlation was based on numerous data from the 4-year field experiment with six radish cultivars and different sowing and harvest dates. The content of thiocyanate in radish roots was found to be positively correlated with their dry weight, and the content of total protein, crude fibre, and soluble sugar. A strong relationship was found between the content of thiocyanate and dry weight of radish leaves. The negative correlation between the thiocyanate content in the leaves and the firmness of storageroots and the positive correlation with their pithiness might indicate the translocation of this compounds into green plant parts during the ageing of root tissue. The root thiocyanate content and the percentage of shooting correlated significantly only in the case of Tokinashi. The closeness of relations between the ratio of leaves/storage-root and thiocyanate content, though in general small, was affected also by a cultivar. A similar effect was observed for the correlations between the thiocyanate contents in leaves and storage-roots.     

Effects of feeding by larvae of Phaedon cochleariae (F.) and Plutella maculipennis (Curt.) on the yield of radish and turnip plants

Different numbers of larvae of the beetle Phaedon cochleariae (F.) and the moth Plutella maculipennis (Curt.) were fed on the leaves of turnip plants (variety Early Milan White) and radish (variety French Breakfast) growing in a constant-environment room. Turnips grew more slowly than radish, were less affected by insect feeding and were affected more by Phaedon than by Plutella. Phaedon larvae severed leaf veins and rasped the leaf surface, thus killing more leaf tissue by desiccation than they ate. They remained on and greatly damaged the older leaves and their feeding reduced yield. Plutella larvae fed on leaves of all ages, which they ate cleanly, leaving the veins. They pupated sooner than Phaedon and did less damage to older leaves, which grew larger and lived longer than corresponding leaves on intact plants. This compensatory growth by turnip prevented loss of yield and may have increased it, as indicated by dry weight of the roots. Both species of insect decreased the yield of radish similarly. Loss of yield of turnip caused by Phaedon or of radish caused by both species of insects was negatively and linearly proportional to the number of larvae that fed on the leaves.     

The effects of daminozide on the levels of Indol-3yl-acetic acid and gibberellins in radish (Raphanus sativus L.) in relation to the control of storage root growth

The levels of indol-3yl-acetic acid and gibberellins were determined in shoots and storage roots of radish (Raphanus sativus L.) at various times during the vegetative growth cycle of control plants and plants in which the root to shoot ratio was modified by daminozide treatment. In control plants the onset of storage organ growth was preceded by a change in the hormone root to shoot ratio to favour the root. There was a general reduction in hormone levels in daminozide-treated plants but the pattern of their distribution in roots and shoots was very similar to that in control plants. Thus the effects of daminozide on increased storage root growth cannot be explained in terms of altered root to shoot hormone ratios.     

Regrowth dynamics of <Emphasis Type="Italic">Calamagrostis epigejos</Emphasis> after defoliation as affected by nitrogen availability

Young plants of a rhizomatous grass Calamagrostis epigejos (L.) Roth were grown from seed in nutrient solutions containing nitrogen in concentrations 0.1, 1.0, and 10 mM. After six weeks of cultivation the plants were defoliated and changes in growth parameters and in content of storage compounds were measured in the course of regrowth under highly reduced nitrogen availability. Plants grown at higher nitrogen supply before defoliation had higher amount of all types of nitrogen storage compounds (nitrates, free amino acids, soluble proteins), which was beneficial for their regrowth rate, in spite of lower content of storage saccharides. Amino acids and soluble proteins from roots and stubble bases were the most important sources of storage compounds for regrowth of the shoot. Faster growth of plants with higher N content was mediated by greater leaf area expansion and greater number of leaves. In plants with lower contents of N compounds number of green leaves decreased after defoliation significantly and senescing leaves presumably served as N source for other growing organs. Results suggest that internal N reserves can support regrowth of plants after defoliation even under fluctuating external N availability. Faster regrowth of C. epigejos with more reserves was mediated mainly by changes in plant morphogenesis.     

Comparative Studies on Ferredoxin-NADP+ Oxidoreductase Isoenzymes Derived from Different Organs by Antibodies Specific for the Radish Root- and Leaf-Enzymes

Determination of the prosthetic group and titration of sulfhydryl group of ferredoxin-NADP+ oxidoreductase (FNR) from roots of radish (Raphanus sativus var acanthiformis cv Miyashige) confirmed its similarity to leaf-FNR. Antisera directed against radish root-FNR and leaf-FNR distinguished the enzyme forms from roots and leaves of radish as well as other flowering plants. The FNR isoenzymes showed organ-specific distributions. In horsetail (Equisetum arvense L.) and cultured liverwort cells (Marchantia polymorpha), at least two FNR isoenzymes were distinguished by the antisera. FNR from Chlorella vulgaris reacted only with the anti-root-FNR antiserum. FNR from a cyanobacterium, Spirulina spp., failed to react with either antiserum.     

镉胁迫对萝卜幼苗活性氧产生、脂质过氧化和抗氧化酶活性的影响

镉胁迫使萝卜幼苗超氧阴离子(O2)、过氧化氢(H2O2)和丙二醛(MDA)含量增加;随着镉浓度提高,超氧化物歧化酶(SOD)活性首先明显上升,然后逐渐下降,甚至低于对照;叶片过氧化氢酶(CAT)活性明显增加,根系CAT活性则减少;根系以及较高浓度镉处理后期叶片的谷胱甘肽还原酶(GR)活性均显著增加.由此推测:在胁迫初期可能主要由SOD和CAT发挥抗氧化作用,而在胁迫后期由于抗坏血酸-谷胱甘肽(AsA-GsH)循环途径的激活,还原型谷胱甘肽和植物络合素含量的提高可能在清除活性氧或者直接螯合镉中起作用.     

Enhancement of Peroxidase, Polyphenol Oxidase and Superoxide Dismutase Activities by Triadimefon in NaCl Stressed Raphanus Sativus L.

The activities of peroxidase, polyphenol oxidase and superoxide dismutase was significantly lower in roots and leaves of NaCl stressed radish (Raphanus sativus L.) plants. Addition of triadimefon to the NaCl stressed plants increased peroxidase, polyphenol oxidase and superoxide dismutase activities, and thereby ameliorated the negative effect of NaCl stress.     

The effect of radish plant rotation around a vertical axis on leaf morphology and lipid composition

The effects of radish (Raphanus sativus L. var. radicula D.C., cv. Rozovo-krasnyi s belym konchikom) plant clockwise rotation (2 rpm) around the vertical axis during their growth on growth parameters and also on the composition and content of polar lipids (PL) and neutral lipids (NL) in plant leaves and fatty acids included in them were studied. Rotation in the plane of the Earth’s magnetic field horizontal component did not affect the number of leaves but declined their total mass by 25%. However, a reduction of the root mass was observed only at elevated temperature. Rotation reduced the ratio of PL to NL by 1.5–2.0 times as compared with control, decreasing the content of such PL as glycoand phospholipids and increasing the content of NL, triacylglycerols and free sterols. Among glycolipids, the content of monogalactosyldiacylglycerols and digalactosyldiacylglycerols was reduced in comparison with stationary control, and among phospholipids the content of phosphatidylcholin was reduced by ∼50%. The ratio of phospholipids to sterols was reduced more than by 30%, indirectly indicating the decreased fluidity of the lipid bilayer of membranes; the ratio PL/NL was reduced as well, indicating an acceleration of age-dependent changes in the rotated plants. Rotation increased the content of linolenic acid and reduced the contents of oleic and erucic acids, thus increasing the index of fatty acid desaturation. We concluded that radish plant clockwise rotation around the vertical axis is an unfavorable factor inducing the appearance of the signs of premature senescence.