Changes in Endogenous Growth Kegulators in Loblolly Pine Seeds During the Process of Stratification and Germination

The seeds of loblolly pine (Pirns taeda L.) were cold-stratified for 0, 14, 28, 42, and 56 days. Endogenous growth regulators were extracted from these seeds, and also from the germinating and the 28-day warm stratified seeds. Partially purified extracts were separated on chromatographic paper. The chromatograms were cut into 10 equal segments, and these were tested for biological activity using three different btoassays. The results indicated that the unstratified seeds and those stratified up to a period of 28 days contained very little or no growth promoter (GA-like substances), and a relatively high concentration of an inhibitor (presumably abscisic acid), Following 42-day stratification, the promoter concentration gradually increased while the inhibitor level fell almost to zero. A high level of promoter but no inhibitor was detected in germinating seeds. No auxin-like activity was noted in the unstratified seeds. This activity slowly increased up to a period of 28 days and remained at this level for the subsequent stratification periods. However, the activity greatly increased in the germinating seeds. Very little changes in the levels of growth regulators were noted in warm-stratified seeds as compared to the unstrati-fied controls.     

Germination Promotion of Loblolly Pine and Baldcypress Seeds by Stratification and Chemical Treatments

The effects of 4 chemicals on the germination promotion of stratified and unstratified seeds of loblolly pine (Pinus taeda) and baldcypress (Taxodium distichum) were studied. The chemicals used were gibberellic acid, kinetin, potassium nitrate and thiourea, each at 3 different concentrations. Stratification promoted the germination of both seed species. Certain concentrations of gibberellic acid, potassium nitrate and thiourea improved the germination of unstratified loblolly pine and baldcypress seeds while kinetin had no stimulatory effect. All 4 chemicals at specific concentrations promoted the germination of loblolly pine seeds stratified for a short period of time. Considering both speed and completeness of germination, best results were obtained when 21-day stratified seeds were treated with either gibberellic acid (100 mg/1) or kinetin (10 mg/1). In baldcypress, on the other hand, none of these chemicals had any stimulatory effect on the germination of stratified seeds. Germination of both species of seeds was either partially or completely inhibited by the highest concentration of thiourea (30,000 mg/1) used.     

农杆菌对大麦种子萌发及幼苗生长发育的影响

以大麦品种(系)为主区('云引大麦Ⅰ'、'云引大麦Ⅱ'和'U008'),农杆菌浸种时间为副区(0.5、1.5和2.5 h),农杆菌菌液浓度为副副区(0.5、1.5和2.5 OD),采用再裂区试验研究了农杆菌浸种处理对大麦种子萌发和幼苗生长发育的影响.结果表明:品种、农杆菌菌液浓度、浸种时间对大麦的种子发芽率、幼苗高度、幼苗鲜重、叶绿素含量、丙二醛(MDA)含量影响无显著的互作效应,而对幼苗POD活性的影响存在显著互作效应;随着浸种时间的延长和菌液浓度的增加,各大麦品种(系)的种子发芽率、幼苗高度、幼苗鲜重、叶绿素含量均呈逐渐降低趋势,幼苗MDA含量则逐渐增加,并以'U008'变化幅度最大;在菌液浓度为0～1.5 OD、浸种时间为0～1.5 h范围内,幼苗POD活性随着菌液浓度的增加和浸种时间的延长而增强,超过该范围则均呈下降趋势,并以'U008'下降最为明显.可见,农杆菌处理对大麦种子萌发和幼苗生长发育有抑制作用,并在菌液浓度超过1.5 OD、浸种时间大于1.5 h时达极显著水平,且大麦品种间存在一定差异.     

Stored mRNA in Pine Seeds: Prolonged Preservation in Dry Seeds and Disappearance during Germination

RNA blot hybridization was performed with cDNA clones of storedmRNA in dry seed of Pinus thunbergii. The stored mRNA specieswere preserved in the dry seeds for at least 14 years. One ofthe mRNAs disappeared rapidly during germination, while otherswere detected until a late stage of germination. (Received August 19, 1991; Accepted February 26, 1992)     

Changes in Seed Constituents During Germination and Seedling Growth of Precociously Matured Soybean Seeds(Glycine max)

During 7 d of precocious maturation of soybean seed (Glycinemax), the starch content declined and soluble sugar levels increasedin patterns similar to natural seed dehydration and maturation.Total seed protein content and total seed dry weight increasedwhereas oil content remained relatively unchanged. Overall,the proportions of the constituents in precociously maturedseeds were comparable to naturally mature seeds. Precociouslymatured soybean seeds showed much the same germination and seedlinggrowth frequency patterns as naturally matured seeds. Duringgermination and seedling growth of precociously matured seeds,starch, soluble sugar, protein and oil levels followed patternssimilar to naturally mature, germinating seeds and seedlings.Therefore, precocious maturation may be used as a model systemto investigate the control of the physiological and biochemicalevents occurring during seed maturation which lead to germinationand subsequently, seedling growth. Glycine max (L.) Merr., soybean, cotyledons, maturation, germination/seedling growth     

Changes in Levels of alpha-Amylase Components in Barley Tissues during Germination and Early Seedling Growth

Kernels of Klages barley (Hordeum vulgare L.) were germinated for 1 to 4 days on moist sand at 18°C. Representative kernels from each time period were dissected to give the following fractions: scutellum, subscutellar endosperm, aleurone-scutellum interface, remaining aleurone, subaleurone endosperm, and core endosperm. These tissues were analyzed for α-amylase components by isoelectric focusing and rocket-line immunoelectrophoresis. Although aleurone and scutellar tissues appeared to synthesize the same α-amylase components, enzyme was detected first in the scutellum. A larger proportion of scutellar α-amylase was excreted into the endosperm compared to aleurone synthesized α-amylase. Aleurone cells appeared to synthesize appreciably more α-amylase than did scutellar tissue.     

Increase in beta-N-Acetylglucosaminidase Activity during Germination of Cotton Seeds

A marked increase in beta-acetylglucosaminidase (2-acetamido-2-deoxy-beta-d-glucoside acetamidodeoxyglucohydrolase, EC 3.2.1.30) activity was observed in the germinating cotyledon of cotton seeds. The enzyme was isolated from cotton seedlings and purified to study its physiological function in the germination of cotton seeds. The purification procedure involves ammonium sulfate fractionation, ion-exchange chromatography, gel filtrations, and concanavalin A-Sepharose 4B chromatography, and the purified beta-N-acetylglucosaminidase was shown to be homogeneous by disc electrophoresis. The molecular weight was estimated to be about 125,000 by gel filtration. The enzyme hydrolyzed both p-nitrophenyl-N-acetyl-beta-d-glucosamine and p-nitrophenyl-N-acetyl-beta-d-galactosamine. When p-nitrophenyl-N-acetyl-beta-d-glucosamine was used as substrate, K(m) and V(max) were 0.625 nanomolar and 228 moles per minute per milligram, respectively, and optimum activity was at pH 5.6. The enzyme liberated beta-linked N-acetyl-glucosamine from chitin, ovalbumin, and pronase-digested wheat germ lectin.     

Influence of Ultraviolet Radiation on Germination and Early Seedling Growth

The influence of UV-B radiation (280–320 nm) from filtered and unfiltered FS-40 fluorescent sunlamps on germination and early seedling growth was examined for a range of vegetables (tomato, radish, cucumber, lettuce, and bean) and field crops (wheat, cotton, soybean, and millet). Continuous exposure of seeds for 3 days to 26.9 × 10⁻² W × m⁻² UV-B radiation (280–320 nm) at 25°C, had a slight effect on fresh weight of seedlings but no appreciable influence on germination percentage, or dry weight of seedlings. Extending the time of exposure to 6 days, however, resulted in abnormal seedling growth in all species but wheat. Typical responses were short, stubby roots, bronzing of the cotyledons, increased pigmentation, and abnormal curvature of the shoots.     

农杆菌浸种处理对小麦种子萌发及幼苗生长发育的影响

以小麦品种(系)郑9023、中13和西农1376为主区,分别以农杆菌菌液浓度、农杆菌生长阶段和农杆菌侵染时间为副区,研究了农杆菌浸种处理后小麦种子萌发及幼苗生理生化特性变化.结果表明,小麦品种(系)分别与农杆菌菌液浓度、农杆菌生长阶段和侵染时间的互作效应不显著;随着农杆菌菌液浓度的增加,小麦种子发芽率、幼苗株高、鲜重、叶绿素含量呈下降趋势,MDA含量、白化苗率、卡那霉素抗性苗率则呈上升趋势,而POD活性则呈先升后降的趋势,小麦种子及幼苗受到的伤害逐渐增大,尤其是农杆菌菌液浓度超过1.5 OD后小麦幼苗受到的伤害更为明显;对数生长阶段的农杆菌活性最高,该阶段处理的小麦种子发芽率、幼苗株高、鲜重、叶绿素含量达到最低,而POD活性、MDA含量、白化苗则达到最大,小麦种子及幼苗受到的伤害也最为明显;随着农杆菌侵染时间的延长,小麦种子萌发及幼苗生长发育的各项指标表现出与农杆菌菌液浓度处理相同的变化趋势,尤其是侵染时间超过1.5 h时,小麦种子萌发及幼苗生长发育受到了显著抑制;各小麦不同品种(系)对农杆菌的反应存在一定基因型差异.研究发现,依据小麦种子萌发及幼苗生理生化特性影响和卡那霉素抗性苗率表现,浸种转化法中的农杆菌菌液浓度应控制在1.5 OD左右,生长阶段宜选用对数生长期,侵染时间以1.5 h较为适宜.     

Changes in Amino Acid Composition during Germination of Soybean

Malonogalactan, a malonylated polysaccharide (—74° (c=1.6, H₂O)) produced by Penicillium citrinum, consisted of d-galactose and malonic acid in the approximate molar ratio of 3:1. Molecular weight of the demalonylated galactan (-99° (c=4.6, H₂O)) was about 40,000. From the data regarding optical rotation, nuclear magnetic resonance spectrum, infrared spectrum, glycosidase susceptibility, periodate oxidation, Smith degradation, methylation and acid hydrolysis, the possible structure of the Penicillium malonogalactan is deduced as follows: A galactan, 1,5-β-galactofuranoside polymer esterified with malonic acid at the position of 2 or 3.     

Changes in Amino Acid Composition during Germination of Soybean

α- and γ-Glutamylaspartic acids were detected in acidic fraction of soybean seedling. R_F values of both peptides were consistent with those of authentic samples with several solvent systems.     

Changes in Amino Acid Composition during Germination of Soybean

As a fundamental approach to the problem of amino acid metabolism in soybean, changes in content of twenty-three free amino acids, two acidic peptides, ammonia, ethanolamine, urea and seventeen total amino acids of cotyledon, hypocotyl and root of soybean during germination were determined with an amino acid analyzer. Glycine Max M. var. T201 (non-nodule-forming) and Glycine Max M. var. T202 (nodule-forming) were used for this experiment. The content and composition of free and total amino acids of cotyledon in both T201 and T202 differ from those of other tissues in any stage of germination. However, no significant difference between these two varieties of soybean has been recognized in patterns of free and total amino acids changes during germination.

In dry bean and initial stage of germination a relatively large unknown peak appeared and disappeared thereafter when the change in free amino acid content during germination of soybean was analyzed with amino acid analyzer. From various tests on the unknown peak, it became obvious that the peak was consisted of two peptides, γ-glutamyl-tyrosine and γ-glutamylphenylalanine, which were discovered in soybean by Thompson et al. in 1962. The content of these peptides did not change during the first 20 hours of germination, but they decreased rapidly thereafter and disappeared after 70 hours.     

氨基酸厂废水对植物种子萌发和幼苗生长影响的研究

水稻、大麦、油菜等种子在不同条件下的发芽试验,表明氨基酸厂废水对植物种子萌发存在明显的抑制作用,且这种抑制作用主要表现在出芽阶段生物化学代谢最旺盛的时期,发现淀粉性种子对废水的忍耐程度要低于油脂性种子,同时进行的植物幼苗试验显示,大麦土培时废水最适宜的浓度为１：１００－１：１５０（废水原液与清水体积之比,下同）,水稻砂培为１：１００。     

花生种子的磁处理对其萌发及幼苗生长的影响

本试验着重研究了用交、直流磁场对花生种子进行处理后,在种子萌发及幼苗生长过程中产生的影响。结果表明,一定强度的交流或直流磁场对种子的萌发及幼苗生长有一定的促进作用。处理过的种子存放一年后,磁场对种子萌发的作用依然存在。     

Studies on the Germination of Pine Pollen (Pinus mugo) in vitro. I. Growth Conditions and Effects of pH and Temperature on Germination, Tube Growth and Respiration

The ability of pine pollen to grow in vitro is discussed in relation to its in situ. Optimal conditions of growth in vitro were investigated. All the experiments were made with pollen of Pinus mugo Turra. A satisfactory medium is described as that which at pH 5.2 and at 29 °C can lead to a tube growth bigger than in vivo. The initial growth (0–30) hours) in terms of tube growth and respiration is described in detail. It is shown that a correlation exists between tube growth and respiration. A method for estimating the metabolism and growth of the pollen tube, based on the uptake of ³²p-labelled phosphate, is described. Addition of known stimulators of plant growth and extension does not stimulate tube growth. Temperature studies show that under 20°C germination does not take place.     

Embryo and Endosperm Metabolism of Barley Seeds during Early Germination

Embryos detached from germinating barley seeds were immersedin tritiated water or solutions containing ¹⁴C-labelled compounds.Amino acids rapidly became radioactive and later acids of theKrebs cycle. Labelled alanine did not give rise to radioactivesucrose.     

Protein Synthesis During Rehydration, Germination and Seedling Growth of Naturally and Precociously Matured Soybean Seeds (Glycine max)

p. 86, line 6, should read: These patterns of soluble protein synthese are similar to thoseobserved after precocious maturation and subsequent rehydrationof castor bean (Kermode and Bewley, 1985a, b, 1986), and withinaxes of Phaseolus vulgaris L. seeds (Dasgupta and Bewley, 1982). instead of: These pattern of protein synthesis. Unlike castor bean thoseobserved after precocious maturation and subsequent rehydrationof castor bean (Kermode and Bewley, 1985a, b, 1986), and withinaxes of Phaseolus vulgaris L. seeds (Dasgupta and Bewley, 1982).     

Protein Synthesis During Rehydration, Germination and Seedling Growth of Naturally and Precociously Matured Soybean Seeds (Glycine max)

Soybean seeds [Glycine max (L.) Merr.] synthesize de novo andaccumulate several non-storage, soluble polypeptides duringnatural and precocious seed maturation. These polypeptides havepreviously been coined ‘maturation polypeptides’.The objective of this study was to determine the fate of maturationpolypeptides in naturally and precociously matured soybean seedsduring rehydration, germination, and seedling growth. Developingsoybean seeds harvested 35 d after flowering (mid-development)were precociously matured through controlled dehydration, whereasnaturally matured soybean seeds were harvested directly fromthe plant. Seeds were rehydrated with water for various timesbetween 5 and 120 h. Total soluble proteins and proteins radio-labelledin vivo were extracted from the cotyledons and embryonic axesof precociously and naturally matured and rehydrated seed tissuesand analyzed by one-dimensional PAGE and fluorography. The resultsindicated that three of the maturation polypeptides (21, 31and 128 kDa) that had accumulated in the maturing seeds (maturationpolypeptides) continued to be synthesized during early stagesof seed rehydration and germination (5–30 h after imbibition).However, the progression from seed germination into seedlinggrowth (between 30 and 72 h after imbibition) was marked bythe cessation of synthesis of the maturation polypeptides followedby the hydrolysis of storage polypeptides that had been synthesizedand accumulated during seed development. This implied a drasticredirection in seed metabolism for the precociously maturedseeds as these seeds, if not matured early, would have continuedto synthesize storage protein reserves. Glycine max (L.) Merr, soybean, cotyledons, maturation, germination/seedling growth     

The Regulatory Role of the Embryo on the Development of Isocitrate Lyase Activity during Germination of Ponderosa Pine Seeds

The specific activity of isocitrate lyase rapidly increased in the megagametophytic tissue of cold-stratified seeds of ponderosa pine (Pinus ponderosa Laws) prior to and after germination. When the embryo was removed at germination, isocitrate lyase activity continued to develop. However, in the total absence of the embryo, only a small increase in the specific activity of the enzyme was observed. The development of the enzyme was inhibited by cycloheximide, actinomycin D and abscisic acid. The embryo produced an unidentified factor which enhanced the development of isocitrate lyase activity in the megagametophytic tissue. This embryo factor could not be replaced by the hormones indoleacetic acid (IAA), gibberellic acid (GA₃) or benzylaminopurine (BA). Indoleacetic acid had little effect upon enzyme development. Gibberellic acid and benzylaminopurine inhibited isocitrate lyase development in the megagametophytic tissue of the seed.