Preparation of selenium-enriched sprouts and identification of their selenium species by high-performance liquid chromatography-inductively coupled plasma mass spectrometry

Sprouts of several plants (10 families and 28 species) were cultivated in a high selenium environment, and the chemical species of selenium in these selenium-enriched sprouts were identified by using high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). Cultivation of sprouts of kaiware daikon (type of radish) with 5.0 microg/ml or 10.0 microg/ml of selenium as selenite inhibited the growth. However, no abnormalities in the shape or color were apparent even in the sprouts exposed to 10.0 microg/ml of selenium. The selenium concentration in the sprouts of most plants examined was higher than that from environmental exposure. Among the types of selenium that were accumulated, a large part (69-98%) was extractable in 0.2 M HCl. Chemical analysis of selenium in the HCl extract showed that the main selenium species in all the sprouts examined was Se-methylselenocysteine. In addition to Se-methylselenocysteine, selenomethionine, non-metabolized selenite, gamma-glutamyl-Se-methylselenocysteine and an unknown selenium compound were also detected in several high-selenium sprouts. Since higher anticarcinogenic activities of these monomethylated selenoamino acids have been observed, it is anticipated that such selenium-enriched sprouts will be used as a foodstuff for cancer prevention.     

Effect of vitamin B12-enriched thraustochytrids on the population growth of rotifers

Newly isolated thraustochytrids showed uptake of vitamin B12 from the culture into the cells. Cultivation of thraustochytrids in a medium containing 1 microg/ml of vitamin B12 greatly increased the contents of vitamin B12 in the cells. Similarly to Schizochytrium limacinum, odd numbered fatty acids decreased in the cells of new isolates cultivated with vitamin B12. Vitamin B12-enriched thraustochytrids, strain mh0186, enhanced the population growth of rotifers fed on the cells as sole feed.     

东北森林两种典型阔叶树种子和幼苗对15N同位素的富集响应

以东北森林两种典型的阔叶树种风力传播种子——花曲柳和色木槭种子为研究对象,通过室内¹⁵N尿素浸泡试验和温室盆栽试验,设置4个浓度(0、0.05、0.1和0.2 g·L^-1)、3个浸泡时间(4、8和12 d)与4个叶期(2、4、6和8叶)处理,研究种子浸泡浓度、浸泡时间和幼苗叶期对种子和幼苗¹⁵N富集的影响.结果表明: 浸泡浓度和浸泡时间对两树种种子δ¹⁵N值均有显著的正反馈作用,高浓度和长时间(0.2 g·L^-1+12 d)更有利于种子¹⁵N总量的富集,花曲柳和色木槭种子¹⁵N同位素最大富集倍数的浸泡浓度和浸泡时间组合分别为0.1 g·L^-1+(4、8 d)和0.05 g·L^-1+(4、8 d);δ¹⁵N值稀释率随幼苗株高的增加先急剧减少(2~6叶)后趋于稳定,幼苗从8叶开始叶片¹⁵N总量降低,表明6叶幼苗更适合追踪幼苗的来源;幼苗叶片δ¹⁵N值与种子浸泡浓度、浸泡时间和种子的δ¹⁵N值呈显著正相关.花曲柳和色木槭种子及幼苗均能成功富集到¹⁵N信号,采用0.1 g·L^-1+8 d+6叶组合最适合追踪花曲柳和色木槭种子和幼苗.     

东北森林两种典型阔叶树种子和幼苗对15N同位素的富集响应

以东北森林两种典型的阔叶树种风力传播种子——花曲柳和色木槭种子为研究对象,通过室内¹⁵N尿素浸泡试验和温室盆栽试验,设置4个浓度(0、0.05、0.1和0.2 g·L^-1)、3个浸泡时间(4、8和12 d)与4个叶期(2、4、6和8叶)处理,研究种子浸泡浓度、浸泡时间和幼苗叶期对种子和幼苗¹⁵N富集的影响.结果表明: 浸泡浓度和浸泡时间对两树种种子δ¹⁵N值均有显著的正反馈作用,高浓度和长时间(0.2 g·L^-1+12 d)更有利于种子¹⁵N总量的富集,花曲柳和色木槭种子¹⁵N同位素最大富集倍数的浸泡浓度和浸泡时间组合分别为0.1 g·L^-1+(4、8 d)和0.05 g·L^-1+(4、8 d);δ¹⁵N值稀释率随幼苗株高的增加先急剧减少(2~6叶)后趋于稳定,幼苗从8叶开始叶片¹⁵N总量降低,表明6叶幼苗更适合追踪幼苗的来源;幼苗叶片δ¹⁵N值与种子浸泡浓度、浸泡时间和种子的δ¹⁵N值呈显著正相关.花曲柳和色木槭种子及幼苗均能成功富集到¹⁵N信号,采用0.1 g·L^-1+8 d+6叶组合最适合追踪花曲柳和色木槭种子和幼苗.     

Culture conditions influencing phytase production of Mitsuokella jalaludinii,a new bacterial species from the rumen of cattle

AIMS: To determine the effectiveness of combined treatments with chemicals, heat and ultrasound in killing or removing Salmonella and Escherichia coli O157:H7 on alfalfa seeds intended for sprout production. METHODS AND RESULTS: Alfalfa seeds inoculated with Salmonella or E. coli O157:H7 were treated with ultrasound (38.5-40.5 kHz) in solutions containing 1% Ca(OH)(2), 1% Tween 80, 1% Ca(OH)(2) plus 1% Tween 80, 160 microg ml(-1) Tsunami 200 and 0.5% Fit at 23 and 55 degrees C for 2 and 5 min. Highest reductions were in chemical solutions at 55 degrees C, but seed viability was also reduced compared with treatment at 23 degrees C. Inactivation of Salmonella and E. coli O157:H7 was generally enhanced by simultaneous treatments with ultrasound, chemicals and heat. CONCLUSIONS: Ultrasound treatment, in combination with chemicals and heat, had a modest enhancing effect on the effectiveness of chemicals in killing or removing pathogens on alfalfa seeds. Overall, treatment with 1% Ca(OH)(2) was most effective in killing Salmonella and E. coli O157:H7. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of 1% Ca(OH)(2) instead of 20,000 microg ml(-1) chlorine, which is currently recommended as a sanitizer for seeds intended for sprout production in the US, should be considered. Ultrasound treatment of alfalfa seeds containing Salmonella or E. coli O157:H7, in combination with chemical treatment, contributes to achieving greater reductions in populations of these pathogens, thereby reducing the risk of contamination and the presence of pathogens in sprouts produced from these seeds.     

Thiamine prevents X-ray induction of genetic changes in human lymphocytes in vitro

The effects of thiamine (vitamin B1) on the level of spontaneous or radiation-induced genetic changes in human lymphocytes in vitro were studied. Cultured lymphocytes were exposed to increasing concentrations of thiamine (0-500 microg/ml) and irradiated with X-rays. The DNA damage was estimated as the frequency of micronuclei and apoptotic or necrotic morphological changes in fixed cells. The results show that thiamine alone did not induce genetic changes. A significant decrease in the fraction of apoptotic and necrotic cells was observed in lymphocytes irradiated in the presence of vitamin B1 at concentrations between 1-100 microg/ml compared to those irradiated in the absence of thiamine. Vitamin B1 at 1 and 10 microg/ml decreased also the extent of radiation-induced formation of micronuclei. Vitamin B1 had no effect on radiation-induced cytotoxicity as measured by nuclear division index. The results indicate that vitamin B1 protects human cells from radiation-induced genetic changes.     

Novel lipid-peroxidation- and cyclooxygenase-inhibitory tannins from Picrorhiza kurroa seeds

From the AcOEt extract of the seeds of Picrorhiza kurroa were isolated picrorhiza acid (1), picrorhizoside A (2), picrorhizoside B (3), picrorhizoside C (4), (-)-shikimic acid (5), gallic acid (6), ellagic acid (7), isocorilagin (8), 1-O-galloyl-beta-D-glucose (9), 1-O,3-O,6-O-trigalloyl-beta-D-glucose (10), and 1-O,2-O,3-O,4-O,6-O-pentagalloyl-beta-D-glucose (11), and their structures were established by extensive NMR and chemical studies. Constituents 1-4 are novel compounds, and the known compounds 5-11 have been isolated for the first time from the seeds of P. kurroa. Compounds 2 and 3 were hydrolyzed and yielded 12, isochebulic acid. Compounds 1-12 showed 89.6, 77.3, 56.1, 50.5, 11.0, 86.4, 50.5, 29.2, 70.9, 50.5, 56.5, and 86.1% inhibition of lipid peroxidation at 5 microg/ml, respectively. The commercial antioxidants BHA (1.8 microg/ml), BHT (2.2 microg/ml), and TBHQ (1.66 microg/ml) inhibited lipid peroxidation at 85.6, 87.1, and 81.1%, respectively. The inhibition of cyclooxygenase-1 (COX-1) by 2-5, 7, 8, and 10-12 at 100 microg/ml was 41.9, 28.4, 32.9, 9.3, 70.7, 34.7, 16.0, 89.6, and 53.4%, respectively. Similarly, compounds 1-8 and 11 and 12, at 100 microg/ml, inhibited COX-2 by 12.6, 15.3, 25.1, 5.3, 13.2, 21.7, 2.0, 42.4, 43.4, and 36.9%, respectively.     

内生拮抗细菌在哈密瓜植株体内的传导定殖和促生作用研究

采用抗生素标记的方法研究了内生拮抗细菌P38和B167菌株在哈密瓜植株体内的定殖动态和对植株生长的影响.结果表明,接种方法显著影响P38菌株在植株体内的定殖和传导,并以浸种处理最佳,蘸根和灌根处理次之,喷叶处理最差;浸种可使P38菌株在根、茎、叶中良好传导和稳定定殖,随着植株的生长,根内菌量呈下降趋势,而茎、叶内的含菌量先上升后下降;P38菌株还具有促进哈密瓜种子萌发和植株生长的作用.B167菌株只在根内定殖,在体内的扩展性较差,不能进入叶片;它对植株的生长表现出一定的抑制作用.     

A new anti-counterfeiting method: fluorescent labeling by safranine T in tobacco seed

Counterfeit seeds cause a large loss in seed industry and crop production. Present study was undertaken to find a new anti-counterfeiting technology by labeling seeds with a fluorescent compound, safranine T (ST). Response surface analysis (RSA) experiment with two factors (ST concentration and seed soaking time) of 14 combinations was performed to investigate the ST effects on seed vigor and fluorescence showing in seedlings of two tobacco varieties, MS Yunyan 85 and Honghua Dajinyuan. After soaking in ST solutions, tobacco seeds were germinated for 16 days, then the germination index (GI), vigor index (VI), length of roots and shoots were determined. The optimum combinations of ST concentration and soaking time on GI, VI and length of shoots and roots were 0.57–0.69 mg/ml and 6.77–9.34 h for MS Yunyan 85 and 0.51–0.80 mg/ml and 5.81–7.39 h for Honghua Dajinyuan, respectively. Meanwhile, tobacco seedlings, treated with ST solutions from 0.3 to 1.5 mg/ml showed obviously fluorescence under illumination of green light. It suggests that soaking tobacco seeds in safranine T solution of suitable concentration can be used as a labeling technique for anti-counterfeiting in tobacco seeds.     

Dormancy and Impotency of Cocklebur Seeds. IX. Changes in ACC-Ethylene Conversion Activity and ACC Content of Dormant and Nondormant Seeds during Soaking

Differences in ethylene production between dormant (D) and nondormant(ND) lower seeds of cocklebur (Xanthium pennsylvanicum Wallr.)were studied with respect to changes in the activity of conversionof 1-aminocyclopropane-l-carboxylic acid (ACC) to ethylene andin the contents of ACC and malonyl-ACC in their axial-tissuesduring soaking. Superior ethylene production in ND seeds ascompared to D seeds became evident during a soaking period rangingfrom 12–24 h, when the radicle protrusion in ND seedshad not yet occurred. Ethylene production in ND seeds increasedabruptly after the radicle protrusion. The inhibitors of ethyleneproduction, aminoethoxyvinyglycine, cobaltous ion and -aminoisobutyricacid, inhibited the germination of ND seeds, whereas ACC enabledD seeds to germinate. Activity of ACC-ethylene conversion was absent in dry axialtissues and developed with soaking. After 24 h, this activityin ND axes was superior to that in D axes. Under hypoxia, however,the difference in the ACC-conversion activity appeared before24 h. On the other hand, the contents of ACC in both D and NDaxes remained almost unchanged until 24 h of soaking. It isthus suggested that the inferior ethylene production in D seedsis associated mainly with their low activity of ACC-ethyleneconversion, though partly with their low activity of ACC supply. Activity of ACC-ethylene conversion in the axes of ND seedsincreased sharply after radicle protrusion which occurred after24 h of soaking. Correspondingly, the contents of both ACC andmalonyl-ACC increased in the axes of germinated ND seeds. Theseimply that the high ethylene production in the ND seeds in thepost-germination period comes from the increasing activitiesof ACC supply as well as ACC-ethylene conversion in their axes. Key words: Cocklebur seeds, Dormancy, Ethylene production, 1-aminocyclopropane-1-carboxylic acid, Germination, Xanthium     

Investigation of the relationship between seed leachate conductivity and the germination of Brassica seed

Large differences in the leachate conductivities of single seeds after 24 h soaking were observed in five Brussels sprout cultivars. Within each cultivar non-germinable seeds tended to have higher conductivities than germinable seeds, but the conductivity above which seeds failed to germinate varied between cultivars. No conductivity reading or partition value could therefore be considered as an absolute boundary between germinable and non-germinable seeds to allow the prediction of seed germination for all seed lots of the same species. However, the mean conductivity for each sample was significantly correlated with germination (r = 0.83, P < 0.05) and was clearly higher for samples with lower germinations. Differences in the partition values for the five cultivars may have been attributable to the natural age of the seeds. Seeds of Asmer Aries artificially aged rapidly at 20% moisture content for up to 48 h at 45° C showed increasing leachate conductivity with increased time of ageing (r = 0.97, P < 0.01) and decreased germination (r = - 0.88, P < 0.05). Again however the values for germinable and non-germinable seeds of different artificial ages varied. Leakage from seeds was limited by the testa in the first 6 h of imbibition. Solute leakage from embryos of the five cultivars was therefore greater than those for intact seeds but a clear separation of germinable and non-germinable seeds was still not possible from the conductivity readings. The implications of the observed increases in conductivity with increased seed age and decreased germination for the development of a rapid vigour test for small seeded vegetables in conjunction with controlled deterioration are discussed.     

Efficacy of chlorine and heat treatment in killing Salmonella stanley inoculated onto alfalfa seeds and growth and survival of the pathogen during sprouting and storage.

The efficacy of chlorine and hot water treatments in killing Salmonella stanley inoculated onto alfalfa seeds was determined. Treatment of seeds containing 10(2) to 10(3) CFU/g in 100-micrograms/ml active chlorine solution for 5 or 10 min caused a significant (P < or = 0.05) reduction in population, and treatment in 290-micrograms/ml chlorine solution resulted in a significant reduction compared with treatment in 100 micrograms of chlorine per ml. However, concentrations of chlorine of up to 1,010 micrograms/ml failed to result in further significant reductions. Treatment of seeds containing 10(1) to 10(2) CFU of S. stanley per g for 5 min in a solution containing 2,040 micrograms of chlorine per ml reduced the population to undetectable levels (< 1 CFU/g). Treatment of seeds in water for 5 or 10 min at 54 degrees C caused a significant reduction in the S. stanley population, and treatment at > or = 57 degrees C reduced populations to < or = 1 CFU/g. However, treatment at > or = 54 degrees C for 10 min caused a substantial reduction in viability of the seeds. Treatment at 57 or 60 degrees C for 5 min appears to be effective in killing S. stanley without substantially decreasing germinability of seeds. Storage of seeds for 8 to 9 weeks at 8 and 21 degrees C resulted in reductions in populations of S. stanley of about 1 log10 and 2 log10 CFU/g, respectively. The behavior of S. stanley on seeds during soaking germination, sprouting, and refrigerated storage of sprouts was determined. An initial population of 3.29 log10 CFU/g increased slightly during 6 h of soaking, by about 10(3) CFU/g during a 24-h germination period, and by an additional 10 CFU/g during a 72-h sprouting stage. A population of 10(7) CFU/g of mature alfalfa sprouts was detected throughout a subsequent 10-day storage period at 5 degrees C. These studies indicate that while populations of S. stanley can be greatly reduced, elimination of this organism from alfalfa seeds may not be reliably achieved with traditional disinfection procedures. If S. stanley is present on seeds at the initiation of the sprout production process, populations exceeding 10(7) CFU/g can develop and survive on mature sprouts exposed to handling practices used in commercial production and marketing.     

提高防风种子发芽率的实验研究

目的：提高防风种子发芽率,加大黑龙江省地道药材防风的开发力度。方法：分别采用45℃温水浸种12、24h;150w微波辐射15s、20s、25s 30s;流水冲洗防风种子3—4h;柳枝浸出液为萌发剂培养防风种子,同时培养未经处理的种子作为对照组。结果：对照组发芽率为36．67％;温浸组为60．33％;微波15s组发芽率为68．00％,20s组为74．33％,25s组为71．17％,30s组为67．33％;流水组发芽率为84．00％;柳枝组发芽率为68．67％。结论：大规模播种可采用45℃温水浸种12-24h、150w微波辐射20s、流水冲洗3—4h、柳枝浸出液为萌发剂均可提高发芽势、发芽率,缩短发芽历期,改善出芽不齐等现象。     

化学诱变剂EMS对知母种子萌发的影响

以知母（Anemarrhena asphodeloides）种子为材料,分别采用1%、2%、4%、6%浓度的EMS处理6、8、12和24 h,在恒温培养箱内进行种子萌发实验,研究不同浓度的化学诱变剂甲基磺酸乙酯（ethyl methane sulfonate,EMS）处理对知母种子萌发的影响,筛选适宜的诱变浓度和诱变时间。结果表明：随EMS浓度的增加和处理时间的延长,知母种子发芽率呈现逐渐降低的趋势,以相对发芽率达到半致死浓度为标准,6%EMS浸种12和24 h可作为EMS诱导知母建立突变体库的适宜条件。     

DNA damage from micronutrient deficiencies is likely to be a major cause of cancer

A deficiency of any of the micronutrients: folic acid, Vitamin B12, Vitamin B6, niacin, Vitamin C, Vitamin E, iron, or zinc, mimics radiation in damaging DNA by causing single- and double-strand breaks, oxidative lesions, or both. For example, the percentage of the US population that has a low intake (<50% of the RDA) for each of these eight micronutrients ranges from 2 to >20%. A level of folate deficiency causing chromosome breaks was present in approximately 10% of the US population, and in a much higher percentage of the poor. Folate deficiency causes extensive incorporation of uracil into human DNA (4 million/cell), leading to chromosomal breaks. This mechanism is the likely cause of the increased colon cancer risk associated with low folate intake. Some evidence, and mechanistic considerations, suggest that Vitamin B12 (14% US elderly) and B6 (10% of US) deficiencies also cause high uracil and chromosome breaks. Micronutrient deficiency may explain, in good part, why the quarter of the population that eats the fewest fruits and vegetables (five portions a day is advised) has about double the cancer rate for most types of cancer when compared to the quarter with the highest intake. For example, 80% of American children and adolescents and 68% of adults do not eat five portions a day. Common micronutrient deficiencies are likely to damage DNA by the same mechanism as radiation and many chemicals, appear to be orders of magnitude more important, and should be compared for perspective. Remedying micronutrient deficiencies should lead to a major improvement in health and an increase in longevity at low cost.     

Genetic mapping of QTLs conditioning soybean sprout yield and quality

Soybean sprouts have been used as a food in the Orient since ancient times. In this study, 92 restriction fragment length polymorphism (RFLP) loci and two morphological markers (W1 and T) were used to identify quantitative trait loci (QTLs) associated with soybean sprout-related traits in 100 F₂-derived lines from the cross of ’Pureunkong’×’Jinpumkong 2’. The genetic map consisted of 76 loci which covered about 756 cM and converged into 20 linkage groups. Eighteen markers remained unlinked. Phenotypic data were collected in 1996 and 1997 for hypocotyl length, percentage of abnormal seedlings, and sprout yield 6 days after germination at 20°C. Hypocotyl length was determined as the average length from the point of initiation of the first secondary root to the point of attachment of the cotyledons. The number of decayed seeds and seedlings, plus the number of stunted seedlings (less than 2-cm growth), was recorded a s abnormal seedlings. Seed weight was determined based on the 50-seed sample. Sprout yield was recorded as the total fresh weight of soybean sprouts produced from the 50-seed sample divided by the dry weight of the 50-seed sample. Four QTLs were associated with sprout yield in the combined analysis across 2 years. For the QTL linked to L154 on the Linkage Group (LG) G the positive allele was derived from Pureunkong (R ² = 0.19), whereas at the other three QTLs (A089 on LG B1, A668n on LG K and B046 on LG L) the positive alleles were from Jinpumkong 2. QTLs conditioning seed weight were linked to markers A802n (LG B1), A069 (LG E), Cr321 (LG F) and A235 (LG G). At these four markers, the Jinpumkong allele increased seed weight. Markers K011n on LG B1, W1 on LG F and A757 on LG L were linked to QTLs conditioning hypocotyl length; and Bng119, K455n and K418n to QTLs conditioning the abnormal seedlings. The QTLs conditioning sprout yield were in the same genomic locations as the QTLs for seed weight identified in this population or from previously published research, indicating that QTLs for sprout yield are genetically linked to seed-weight QTLs or else that seed-weight QTLs pleiotropically condition sprout yield. These data demonstrate that effective marker-assisted selection may be feasible for enhancing sprout yield in a soybean. The transgressive segregation of sprout yield, as well as the existence of two QTLs conditioning greater than 10% of the phenotypic variation in sprout yields provides an opportunity to select for progeny lines with a greater sprout yield than currently preferred cultivars such as Pureunkong. Received: 23 August 2000 / Accepted: 23 January 2001     

The role of folic acid and Vitamin B12 in genomic stability of human cells

Folic acid plays a critical role in the prevention of chromosome breakage and hypomethylation of DNA. This activity is compromised when Vitamin B12 (B12) concentration is low because methionine synthase activity is reduced, lowering the concentration of S-adenosyl methionine (SAM) which in turn may diminish DNA methylation and cause folate to become unavailable for the conversion of dUMP to dTMP. The most plausible explanation for the chromosome-breaking effect of low folate is excessive uracil misincorporation into DNA, a mutagenic lesion that leads to strand breaks in DNA during repair. Both in vitro and in vivo studies with human cells clearly show that folate deficiency causes expression of chromosomal fragile sites, chromosome breaks, excessive uracil in DNA, micronucleus formation and DNA hypomethylation. In vivo studies show that Vitamin B12 deficiency and elevated plasma homocysteine are significantly correlated with increased micronucleus formation. In vitro experiments indicate that genomic instability in human cells is minimised when folic acid concentration in culture medium is >227nmol/l. Intervention studies in humans show: (a) that DNA hypomethylation, chromosome breaks, uracil misincorporation and micronucleus formation are minimised when red cell folate concentration is >700nmol/l folate; and (b) micronucleus formation is minimised when plasma concentration of Vitamin B12 is >300pmol/l and plasma homocysteine is <7.5micromol/l. These concentrations are achievable at intake levels in excess of current RDIs i.e. more than 200-400microgram folic acid per day and more than 2microgram Vitamin B12 per day. A placebo-controlled study with a dose-response suggests that based on the micronucleus index in lymphocytes, an RDI level of 700microgram/day for folic acid and 7microgram/day for Vitamin B12 would be appropriate for genomic stability in young adults. Dietary intakes above the current RDI may be particularly important in those with extreme defects in the absorption and metabolism of these Vitamins, for which ageing is a contributing factor.     

The level of proteins and leakage of solutes in germinating fresh and stored seeds ofCicer arietinum L.

One-year-old seeds of chickpea (Cicer arietinum L. cv. C-235) lost about 23 % germinability and leaked larger quantities of N, P, K, saccharides and proteins into the soaking medium in the first 48 h, as compared with fresh seeds. The protein content in stored seeds decreased more than in fresh seeds, as the soaking progressed.