Effect of volatile metabolites from germinating seeds on the reproduction of the bacteria Listeria monocytogenes and Yersinia pseudotuberculosis

The biological activity of volatile metabolites of germinating seeds of cabbage (Brassica oleacia), carrot (Daukus carota), salad (Zactuca sativa), and corn (Zea mays L.) against Listeria monocytogenes and Yersinia pseudotuberculosis was studied. It was shown that volatile metabolites are transfer factors and can be the sole carbon and energy source for these bacteria. Methanol is the main substance affecting their growth and reproduction.     

Effect of volatile metabolites from germinating seeds on the reproduction of the bacteria Listeria monocytogenes and Yersinia pseudotuberculosis

The biological activity of volatile metabolites of germinating seeds of cabbage (Brassica oleacia), carrot (Daukus carota), salad (Lactuca sativa), and corn (Zea mays L.) against Listeria monocytogenes and Yersinia pseudotuberculosis was studied. It was shown that volatile metabolites are transfer factors and can be the sole carbon and energy source for these bacteria. Methanol is the main substance affecting their growth and reproduction.     

Effect on microorganisms of volatile compounds released from germinating seeds.

Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles. Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components. The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-steril soil and activated charcoal.     

The effect of volatile and gaseous metabolites of swelling seeds on germination of fungal spores

Effects of volatile and gaseous metabolites of swelling seeds of pea, bean, wheat, corn, cucumber, tomato, lentil, carrot, red pepper and lettuce on germination of spores of five genera of fungi were found to depend rather on the fungal than on the plant genus. Germination of spores ofBotrytis cinerea, Mucor racemosus andTrichoderma viride was most severely inhibited. Spores ofVerticillium dahliae were less sensitive and germination of spores ofFusarium oxysporum was inhibited only in two cases. On the other hand, exudates of pea and bean stimulated germination of spores ofFusarium oxysporum. Also spores ofTrichoderma viride germinated better in an atmosphere enriched with exuded metabolites of swelling lettuce seeds. When carbon dioxide produced by the swelling seeds was absorbed in potassium hydroxide, spores ofTrichoderma viride andVerticillium dahliae did not germinate at all, the inhibitory effects of volatile and gaseous exudates on germination of spores ofMucor racemosus were accentuated, and also the percentage of germinated spores ofFusarium oxysporum decreased. Germination of spores ofBotrytis cinerea was not influenced. Absorption of volatile and gaseous metabolites in a solution of potassium permanganate decreased in most cases their inhibitory effects, particularly inBotrytis cinerea.     

Starch phosphorylase enzymes in developing and germinating pea seeds

Phosphorylase has been fractionated during development and germination of seeds of smooth and wrinkled-seeded peas. The total phosphorylase levels have been compared. In addition, a number of other pea tissues and other legumes have been examined. Some kinetic properties of the two enzymes present have been measured. Both enzymes have been further purified by affinity chromatography on Sepharose 4B-starch columns and by sequential gel filtration in the absence and presence of amylopectin. The MW and sub-unit structures of the two enzymes have been examined and their possible roles discussed.     

Effect of iso-osmotic levels of salts and PEG-6000 on enzymes in germinating pea seeds

Effects of iso-osmotic levels of salts (NaCl, CaCl₂, Na₂SO₄) and PEG-6000 on the activity of hydrolytic and nitrogen assimilatory enzymes in pea embryo axis and coty ledon were studied. The activity of nitrate reductase and nitrite reductase in embryo axis and cotyledon and the activity of protease and α-amylase in cotyledon decreased with decreasing medium osmotic potential as compared to control at all the stages of seedling growth. The activity of protease and amylase increases with increasing levels of stress in embryo axis. Sodium chloride induced, stress had more deleterious effects on the activity of nitrate reductase, nitrite reductase and αamylase followed by other salts and PEG-6000. On the other hand, CaCl₂ induced salt stress was more depressive for protease activity. The maximum increase in the activity of protease and amylase was observed in embryo axis at higher concentration of salts and PEG-6000.     

Regulation of diamine oxidase activity in germinating pea seeds

Diamine oxidase present in the cotyledons of germinating pea seeds is induced by putrescine, spermidine and ornithine. Auxins inhibit enzyme synthesis in cotyledons only in the presence of embryo. Cycloheximide inhibits the synthesis of the cotyledon enzyme but has no effect on the embryo enzyme. 5-Fluorouracil inhibits the synthesis of both cotyledon and embryo enzymes.     

RNA synthesis in embryo axes of germinating pea seeds

RNA synthesis during germination was investigated by labelingpea embryo axes or seedling roots with radioactive uridine oradenosine. The results indicated that all RNA species of pre-rRNAs(ribosomal precursor RNAs), rRNAs, heterodisperse-type RNA and4–5S low molecular weight RNA were synthesized from the6th to 64th hour of the period examined. At the very early stageof germination, some conspicuous labeling of the heterodisperse-typeRNA was observed after pulse-labeling. There was no great differencein the labeling patterns of various RNA species with regardto other later stages. When embryo axes were labeled for 1 hrwith ³H-adenosine from the 16th hour, about 25% of the labeledwhole cell RNA was retained on the membrane filter. The ratioof labeled poly(A)-containing RNA, however, decreased as germinationproceeded. The poly (A)-containing RNA sedimented heterodisperselywith a mean value of about 20S in a sucrose density gradient;this size-distribution did not vary throughout germination. (Received January 16, 1979; )     

Biosynthesis of willardiine and isowillardiine in germinating pea seeds and seedlings

The synthesis of the pyrimidinyl amino acids willardiine and isowillardiine was studied in vivo and in vitro. Uracil derivatives stimulate the biosynthesis of both compounds; the free base is the most effective. Significant incorporation of [2-(14)C]uracil and [6-(14)C]orotate into willardiine and isowillardiine was found. Incorporation of [6-(14)C]orotate was substantially decreased in the presence of uracil, and to a lesser extent by uridine and UMP. [3-(14)C]Serine was incorporated into the alanine side chain of the two uracilylalanines but not into the ring. The effect of a number of uracil analogues and inhibitors of pyrimidine metabolism was examined. Some were shown to stimulate the biosynthesis; the most noticeable effects were obtained with 6-azauracil and 2-thiouracil. Attempts to obtain extracts capable of synthesizing the uracilylalanines from uracil and serine were unsuccessful, but weak activity was observed when serine was replaced by O-acetylserine.     

Arginine catabolism in the cotyledons of developing and germinating pea seeds

Arginine is the predominant free amino acid in the cotyledons of developing seeds of Pisum sativum L. cv Marzia. Breakdown of arginine was measured by injecting l-[guanido-¹⁴C]arginine into detached cotyledons. Cotyledons of developing seeds showed a low rate of ¹⁴CO₂ evolution whereas a much higher rate of ¹⁴CO₂ evolution was measured from cotyledons of seeds 4 days after the onset of germination. The activities of the catabolic enzymes arginase, urease, and ornithine aminotransferase were measured throughout development and germination. Arginase and ornithine aminotransferase were present at an early stage of development. Urease activity appeared later as the seeds started to desiccate. During germination, all three enzymes were present. The different course of activity of these enzymes indicates that they are controlled separately.     

Volatile and gaseous metabolites released by germinating seeds of lentil and maize cultivars with different susceptibilities to fusariosis and smut

The effect of volatile and gaseous metabolites released by germinating seeds of lentil cultivars more and less susceptible to fusariosis on the germination of spores ofMucor racemosus, Trichoderma viride, Verticillium dahliae andBotrytis cinerea was found to depend rather on the fungal genus than on the lentil cultivar. However, spores ofFusarium oxysporum reacted more sensitively during germination to the presence of exudates of both cultivars, when the more susceptible lentil displayed a stimulation, the less susceptible one an inhibition of spore germination. The greatest difference in the effect of exudates was observed in the more and less susceptible maize cultivars with respect to the germination of chlamydospores ofUstilago maydis, especially during the first hours of seed germination. Analysis of the exudates of germinating seeds showed the release of a greater amount of ethanol and methanol with acetaldehyde by the more susceptible cultivars of lentil and particularly maize.     

Development of RNase activity in embryonic axes of germinating pea seeds

RNase activity in embryonic pea axes increased in parallel withthe rise of RNA synthesis as germination proceeded. The developmentof this enzymatic activity was modified antagonistically byapplication of GA₃ and ABA and inhibited severely by treatmentwith CH. Sedimentation analysis of ³H-adenosine-labeled RNAindicated that the synthesis of all types of RNA species isuniformly stimulated by GA₃ and inhibited by ABA. However, 5-FUtreatments, which severely inhibited the synthesis of rRNA,with a slight effect on that of mRNA, had no appreciable effecton the development of RNase activity in the axes. These resultsindicate that active RNA synthesis during germination is independentof the development of RNase activity and that the de novo synthesisof RNases may be controlled by the synthesis of their specificmRNAs. Among the three types of RNase (RNase I, II and III) detectedin the embryonic axes, RNase III showed a sharp increase inactivity with embryo growth and the activity of this enzymewas mainly associated with the endoplasmic reticulum. (Received June 5, 1978; )     

Isolation of membranes containing protease from the cotyledons of germinating pea seeds

Membranes containing protease were isolated from the cotyledonsof germinating pea seeds by differential and two successivesucrose density gradient centrifugations. Membranes were recoveredin the microsomal fraction, but could be clearly separated frommembranes carrying antimycin A-insensitive NADH-cytochrome creductase EC 1.6.2.1 [EC] ), which seem to come from the endoplasmicreticulum. The density of protease-containing membranes was1.135. Membranes contained a lower amount of phospholipid ascompared with the endoplasmic reticulum. Electron microscopicobservations also showed that the membranes were different fromthe smooth-surfaced endoplasmic reticulum. ¹Present address: Department of Pathology, Aichi Medical University,Nagakute, Aichi, Japan. (Received September 12, 1973; )     

Carbamoyl phosphate synthetase activity from the cotyledons of developing and germinating pea seeds

Carbamoyl phosphate synthetase activity was measured in partially purified extracts from cotyledons of developing and germinating seeds of Pisum sativum L. Some properties of the enzyme were established. During cotyledon development, the activity initially increased sharply but decreased during further development. The activity from germinating seeds was only one-tenth of the maximum activity at an early developmental phase. The results are discussed in relation to pea seed development and germination.     

Effect of cadmium and nickel on mobilisation of food reserves and activities of hydrolytic enzymes in germinating pigeon pea seeds

Inclusion of cadmium as cadmium chloride and nickel as nickel chloride in media differentially induced dry matter mobilisation from cotyledons of germinating pigeon pea seeds. Cadmium depressed the activities of total amylase, protease, acid phosphatase and peroxidase in germinating seeds. The activities of these enzymes were stimulated at the lower concentrations of nickel and suppressed at the higher ones. This dual response of hydrolytic enzymes to cadmium and nickel is postulated to account for the promotory and inhibitory effects of these heavy metals on dry matter mobilisation.