Trypsin Inhibitors during Germination of Vigna sinensis Seeds

The trypsin inhibiting activity of cotyledonary extracts of serido beans (Vigna sinensis) falls continuously during germination to a value which represents 5 % of the value for the dry seed. The specific activity is constant over the first three days and then decreases, reaching a level at the seventh day of germination which represents 20 % of the initial value. It is also shown that the axial parts control the disappearance of the trypsin inhibiting activity of the cotyledons. The results presented here seem to indicate a role for these substances in the process of germination.     

Effects of Kinetin and Salinity on Germination of Tomato, Barley and Cotton Seeds

The effects of kinetin and the interaction between kinetin andsalinity on seed germination of three plant species namely Lycopersiconesculentum, Hordeum vulgare and Gossypium hirsutum were studiedKinetin was applied exogenously to the seeds in order to determinewhether this growth-promoting hormone would promote germinationand to see if osmotically-induced dormancy caused by NaCl couldbe alleviated The results indicate that kinetin is capable ofbreaking dormancy in these species and there is a significantinteraction with salinity in tomato and cotton Kinetin, germination, salinity, water stress, salt stress, Lycopersicon esculentum Mill, tomato, Hordeum vulgare L, barley, Gossypium hirsutum L, cotton     

Effects of Water Deficit during Germination of Wheat Seeds

Germinating seeds of spring wheat (Triticum aestivum L.) were tolerant to dehydration up to the 4^th day following imbibition and from the 5^th day the seedling survival decreased. Dehydration also inhibited the rate of seed dry mass depletion and seedling dry matter accumulation and increased the content of soluble sugars both in grain and seedlings. Glucose supplied either to dry seeds or to 4-d-old seedlings increased survival of dehydrated seedlings. In contrast, exogenously supplied non-readily metabolizable sorbose and mannose suppressed seedling survival.     

不同氮水平下盐胁迫对大麦幼苗中某些氮化物积累的影响(简报)

在土培条件下,提高氮素供应水平和NaCl处理浓度后大麦幼苗地上部和根中的全氮,蛋白质氮和游离氨基酸总量增加;蛋白质氮占全氮的比值亦因NaCl处理浓度的增大而提高。在盐胁迫下,游离脯氨酸占氨基酸总量的百分比明显增加,而谷氨酸所占比例则下降。     

Involvement of Cyanogens in the Promotion of Germination of Cocklebur Seeds in Response to Various Nitrogenous Compounds, Inhibitors of Respiratory and Ethylene

Nitrogenous inhibitors of respiration, namely, KCN, NaN₃ andNH₂OH, which promote the germination of cocklebur (Xanthiumpennsylvanücum Wallr.) seeds, enhanced the accumulationof cyanogenic compounds. Urea and cyanamide, which were ineffective,did not. Part of the exogenously applied KCN was converted tocyanogenic glycosides and lipids, but these compounds were onlyproduced at low levels in NaN₃-treated seeds. Exposure to NH₂OHcaused a slight accumulation of both types of cyanogenic compounds.Thiourea, effective in stimulating germination, did not increasethe cyanogenic compounds, which suggests that the mechanismof its effect on germination is different from that of othernitrogenous compounds. Thiocyanate had a slightly promotiveeffect and caused minor increases in the levels of cyanogeniccompounds. Ethylene increased the metabolic utilization of the accumulatedcyanogens in response to KCN or NaN₃. The response to ethyleneof seeds in secondary dormancy was restored only after pre-treatmentwith KCN or NaN₃. The response occurred once the level of cyanogenshad increased. By contrast, enhancement of the effects of KCNand NaN₃ on germination by propyl gallate or benzohydroxamate,inhibitors of CN-resistant respiration, was accompanied by theincreased accumulation of cyanogens within the seeds that hadbeen exposed to KCN or NaN₃ in combination with the other typesof respiratory inhibitors. Thus, it is suggested that endogenouscyanogens might be involved in the germination of cockleburseeds. (Received December 20, 1995; Accepted April 9, 1996)     

NaCl胁迫对紫荆花粉萌发特性的影响

以紫荆（Cercis chinensis）为试验材料,采用花粉人工培养法研究不同浓度NaCl对紫荆花粉萌发特性的影响。结果表明：NaCl对紫荆花粉萌发有抑制作用,且抑制程度随培养基中NaCl浓度的增高而加强,NaCl显著抑制(P<0.05)紫荆花粉萌发的浓度为20 mmol/L,显著抑制(P<0.05)花粉管伸长生长的浓度为5 mmol/L。     

Effects of NaCl salinity in vivo and in vitro on ribonuclease activity of Vigna unguiculata cotyledons during germination

Pitiuba bean [ Vigna unguiculata (L.) Walp.] seeds were sown in water or. in 0.1 M NaCl. Seedling growth and cotyledon nucleic acid mobilization were delayed by NaCl salinity. The differences in cotyledonary RNase activity between seeds sown in water and in NaCl solutions suggest that salinity delays the activation and/or de novo synthesis of the enzyme. Cotyledon extracts were subjected to gel filtration through Sephadex G-100, and RNase activity measured. Only one cotyledonary RNase appeared during germination, and salinity did not induce any change in molecular weight of the enzyme. Salinity inhibited 45% of the specific activity of the RNase on the 5th day of the experimental period. The same salt concentration (0.1 M NaCl) added in vitro inhibited only 8 % of the specific activity of the enzyme. This difference may indicate that NaCl in vivo affects mainly the de novo synthesis of the RNase.     

Effect of Dormancy Relieving Compounds on the Seed Germination of Non-dormantAllenrolfea occidentalisunder Salinity Stress

Allenrolfea occidentalis(Chenopodiaceae) is a highly salt tolerantplant species that is widely distributed in inland salt marshesand salt playas of the western United States. We investigatedthe influence of dormancy-relieving compounds (fusicoccin, ethephon,nitrate and thiourea) in alleviating salinity stress on theseed germination ofA. occidentalis. Seed germination decreasedwith an increase in salinity and no seed germinated at 800 mMNaCl.Fusicoccin (5 µM), ethephon (10 mM) and nitrogenous compounds(20 mMnitrate and 10 mMthiourea) were able to counteract theinhibition produced by salinity treatments. All dormancy relievingcompounds significantly (P<0.0001) promoted germination atall salinity concentations. Fusicoccin completely reversed theinhibitory effects of salinity on seed germination ofA. occidentalis.Ethephon application significantly promoted germination at allsalinities. Nitrate and thiourea were relatively less effectivein alleviating the effects of high salinity on germination.Copyright1998 Annals of Botany Company Allenrolfea occidentalis, ethephon, fusicoccin, halophyte, dormancy, nitrate, salinity, seed germination, thiourea.     

Seed Germination of Triglochin Maritima as Influenced by Salinity and Dormancy Relieving Compounds

Triglochin maritima had only 40 % germination in distilled water, but germination was substantially enhanced when seeds were exposed to ethephon, fusicoccin, proline, kinetin, and thiourea. Also, the effect of low salinity on germination was alleviated by fusicoccin, kinetin, nitrate and thiourea, whereas, the reduction in germination at high salinity was partially countered by ethephon, kinetin, thiourea and nitrate.     

Inhibition of Germination of Photosensitive Lettuce Seeds by Phenylmethylsulfonyl Fluoride, an Inhibitor of Proteases

The changes in the amounts of storage peptides in lettuce seedswere estimated during imbibition. Levels of the 32- to 39-kDacomponents of the storage peptides in seeds irradiated withred light began to decrease from the 12th h of imbibition, butthis decrease was completely inhibited by phenylmethylsulfonylfluoride (PMSF, 1 HIM). PMSF decreased the growth potentialof the embryonic axis and thereby inhibited germination. Thepartial breadown of the storage peptides appears to be necessaryif the embryonic axis is to rupture the seed coat and endospermlayer of lettuce seeds. (Received June 4, 1990; Accepted September 4, 1990)     

Effects of Sulphur-containing Compounds on Lettuce Fruit Germination

The germination of Lactuca sativa L. cv. Arctic King fruit ona 0.5 per cent agar substrate was inhibited in light at temperaturesabove 31?C (? 1.0?). This precisely repeatable value, termedthe upper temperature cut-off point, is characteristic for thislettuce variety. The position of this cut-off point is raisedby the presence of thiourea (500–1000 mg/1) and a numberof other thiol compounds. This effect is not shown by all thiolcompounds and is dependent on the configuration of the restof the molecule. The presence of a hydroxyl group in the testcompound often results in the temperature cut-off point beinglowered but again this effect depends on the configuration ofthe rest of the molecule. It is postulated that the stimulatingeffects of active thiol compounds are related to hydrophobicinteractions with a macro-molecule involved in the initiationof germination.     

Sterol Changes during Germination of Nicotiana tabacum Seeds

The identity, composition, and concentration of the total, free, esterified, and glycosidic sterol fractions were determined during germination of tobacco seeds. The total, free, and esterified sterols increased, with stigmasterol and campesterol accounting for most of the increase. Steryl glycosides decreased during germination, and stigmasteryl and sitosteryl glycosides showed the largest decrease. During germination, sitosterol was the major sterol in all fractions but stigmasterol and campesterol showed the greatest changes. The fatty acid composition of the steryl esters and acylated steryl glycosides most closely resembled the di- and triglycerides.     

The Antioxidant System of Wheat Seeds during Germination

The dynamics of peroxidase activity and antioxidant contents in wheat seeds were studied in the course of 24-hour swelling at 5°C (group 1) and 23°C (group 2). Both parameters were 1.5 times higher in seeds of the first group. In the same seeds, peroxidase activity in the endosperm and seed coat increased by factors of 1.5 and 1.8, respectively. Catalytic constants of wheat seed peroxidase were determined in the reactions of o-dianisidine and ascorbic acid peroxidation. In the pH range studied (pH 5–7), K _m proved to change only slightly. In seedlings, an increase in the lipid peroxidation rate was accompanied by an increase in the content of antioxidants. Peroxidase activity increased as the content of antioxidants decreased, and vice versa. Thus, the reciprocal influence of peroxidase and low-molecular antioxidants during seed germination in wheat was revealed.     

当归果翅对种子吸水与发芽进程的影响

研究当归果翅对其种子吸水及发芽进程的影响,旨在为当归规范化栽培提供理论和技术依据。以当归的双悬果果实和去翅种子作为试验材料,对其千粒重、含水量、体积、容重和吸水率进行测定,并在自然室温条件下进行种子发芽试验。结果表明:①当归双悬果去除果翅后,其千粒重减少了46.87%(P<0.01),体积减少了90.78%(P<0.01),容重增加了475.92%(P<0.01),含水量增加了20.15%(P<0.05);②当归果翅抑制了种子吸水吸胀的能力,果翅去除后能在2.48 h内进入稳定期,较去翅前提前了3.38 h,且吸水过程符合逻辑斯蒂方程;③当归果翅对种子发芽具有显著影响,果翅去除后发芽势、发芽率和发芽指数较未去翅种子分别提高了256.7%、12.28%和27.77%,均达到了极显著水平(P<0.01)。当归双悬果去除果翅后,减小了种子体积和重量,并促进了种子吸水吸胀能力,同时还有效地提高了种子的发芽质量。建议在生产中以去翅种子作为播种材料进行播种。     

Changes in mRNA of Vigna mungo Cotyledons during Seed Germination

Quantitative and qualitative changes of mRNA in Vigna mungocotyledons during seed germination have been investigated. TotalRNA is higher in dry cotyledons and declines during germination.Poly(A)⁺ RNA also is present at a relatively high level in drycotyledons, increases slightly during the first day of germination,and then decreases. Polysomal RNA is very low in dry cotyledonsbut increases rapidly during the first day of germination, andthen declines. The translational activity of the mRNA in a wheatgerm cell-free system is low on day 0 but increases rapidlyon day 1 of germination. Two-dimensional gel electrophoresisof in vitro translation products reveals that many new peptidesare synthesized on day 1 of germination. Synthesis of most ofthese polypeptides continue throughout 5 days of germination. Change in the mRNA population during germination has been investigatedusing cDNA against poly(A)⁺ RNA from 3-day-old cotyledons. Withtotal RNA of day 3 and 5, the cDNA strongly hybridized withRNA similar in size to 25 S ribosomal RNA, but no specific bandsare detected with samples of day 0 or 1. With poly(A)⁺ RNA ofday 5 or 1, the cDNA tends to hybridize with RNAs of relativelysmall molecular size. Cordycepin and -amanitin prevent the increasein poly (A)⁺ RNA content and the appearance of new mRNAs duringthe first day of germination. ¹Present address: Division of Regulation of Macromolecular Function,Institute for Protein Research, Suita City, Osaka 565, Japan. (Received January 13, 1986; Accepted June 10, 1986)     

The Effects of Octanoate and Oleate on Isocitrate Lyase Activity during the Germination of Pinus pinea Seeds

The changes of isocitrate lyase levels with respect to the catabolism of triglycerides have been studied during the germination of Pinus pinea seeds. We studied the effects of octanoate, oleate, and inhibitors of protein synthesis on isocitrate lyase during germination. Pyruvate kinase, glucose-6-P-dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase were also assayed. Octanoate and oleate inhibited the isocitrate lyase activity, similarly to cycloheximide, chloramphenicol, and actinomycin, inhibitors of protein biosynthesis. This inhibitory effect is not specific but is strikingly evident with isocitrate lyase. This inhibition was not proportional to the concentration but was proportional to the chain length of oleate and octanoate.     

不同磁处理对芍药种子萌发的影响

目的:研究磁场对芍药种子萌发的影响.方法:采用均匀电磁场分不同的处理强度和处理时间分别磁处理野生芍药种子和栽培芍药种子,种子磁处理后在培养皿中催芽,2个月后统计种子胚根萌发率和胚芽萌发率.结果:3000Gs的磁场处理1.5h能提高野生芍药种子胚芽萌发率和栽培芍药种子胚根萌发率,对于栽培芍药种子4000 Gs的磁场处理2h能够促进胚根和胚芽萌发.结论:一定强度的磁场能打破芍药种子休眠,促进种子的萌发.     

Transfer Cells in Suspensur and Endosperm during Early Embryogeny of Vigna sinensis

During early embryogeny, structural differentiation of the suspensor and endosperm can be observed with the formation of cells with wall ingrowths. In the early proembryo stage, wall ingrowths are seen only on the boundary walls of the embryo sac around the proembryo and at the chalazal end. Later, ingrowths appear in the outer walls of the basal suspensor cells and some wall ingrowths also begin to develop in the outer walls of cellular endospermic cells adjacent to the nucellar cap and the inner integumentary tissues. The suspensor appears to remain active throughout the differentiation stages. Two regions can be clearly distinguished in the suspensor: a basal region and a neck region. Wall ingrowths appear to form only in the cells of the basal region. During the development of the cellular endospermic sheath, its cell number and size both increase slightly. Later, these cells rapidly become separated from each other. Those endospermic cells that abut directly onto the integumentary tissues also develop wall ingrowths. In the region of the fluid endosperm, wall ingrowths are especially abundant in the boundary walls on the ventral side of the embryo sac. The possible pathway of nutrient flow to the developing embryo is discussed.