Nutritional control of the correlative inhibition between lateral shoots in the flax seedling (Linum usitatissimum)

1968 ◽  
Vol 46 (2) ◽  
pp. 147-155 ◽  
Author(s):  
G. I. McIntyre
Keyword(s):  
Linum Usitatissimum ◽  
Cotyledonary Node ◽  
Nutrient Supply ◽  
Mineral Nutrients ◽  
Nitrogen Supply ◽  
The Other ◽  
Sand Culture ◽  
Mineral Nutrient ◽  
Lateral Shoots ◽  
Correlative Inhibition

When the epicotyl of the flax seedling is decapitated one of the two shoots produced at the cotyledonary node tends to inhibit and may completely suppress the growth of the other. By growing the seedlings in sand culture with a controlled mineral nutrient supply it was shown that (a) the inhibiting influence of the dominant shoot was inversely related to the nitrogen level; (b) the inhibited shoot could be released from inhibition by increasing the nitrogen supply; (c) the removal of the dominant shoot was followed within 12 h by an increase in the total nitrogen content of the inhibited shoot; (d) a similar control of inhibition could be obtained by varying the phosphorus supply. These results are consistent with the hypothesis that this form of correlative inhibition is due primarily to competition between the shoots for a limited mineral nutrient supply.When one of the cotyledons was either covered or removed its axillary bud was inhibited by the shoot in the axil of the untreated cotyledon. The degree of inhibition was inversely related to the nitrogen supply. It is suggested as a working hypothesis that the cotyledons provide a factor(s) which promotes the growth of their axillary buds and thus determines their ability to compete for mineral nutrients.

The correlative inhibition of bud and shoot growth in flax (Linum usitatissimum). Some factors affecting the pattern and degree of inhibition

1975 ◽  
Vol 53 (4) ◽  
pp. 390-402 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Shoot Apex ◽  
Linum Usitatissimum ◽  
Nitrogen Nutrition ◽  
Growth Potential ◽  
Sand Culture ◽  
Factors Affecting ◽  
Linum Usitatissimum L ◽  
N Supply ◽  
Lateral Buds ◽  
Correlative Inhibition

When flax (Linum usitatissimum L.) seedlings were grown in sand culture under controlled conditions, growth of the lateral buds and their release from apical dominance showed a positive correlation with the N supply. The response of the buds was related to their position on the shoot and a well-defined gradient of bud growth potential was apparent at all N levels. Removal of the basal buds, which have the highest growth potential, induced the outgrowth of buds at higher nodes and increased the growth of the main shoot apex. Similar effects were produced by increasing the N supply to the intact plant.Providing N only as nitrate inhibited apical growth and caused severe leaf necrosis. These effects were due to zinc deficiency and could be prevented or significantly reduced not only by increasing the zinc supply but also by reducing the N level, providing some NH4-N, reducing the light intensity, or increasing the depth of planting. They could also be prevented by removal of the lateral buds at the basal nodes, thus indicating that the shoot apex and lateral buds may compete for the limited zinc supply. The obviously complex relationship between zinc and nitrogen nutrition in this species requires further investigation.

Developmental studies on Euphorbia esula. The influence of the nitrogen supply on the correlative inhibition of root bud activity

1972 ◽  
Vol 50 (5) ◽  
pp. 949-956 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Nitrogen Supply ◽  
Euphorbia Esula ◽  
Nitrogen Level ◽  
Developmental Studies ◽  
Subsequent Increase ◽  
Lateral Buds ◽  
Lateral Shoots ◽  
Correlative Inhibition ◽  
Low Nitrogen

When seedlings of leafy spurge (Euphorbia esula L.) were grown at a low nitrogen level (10.5 ppm) the growth of the lateral buds on the shoot was completely arrested by apical dominance while the buds on the roots, although also inhibited, showed considerably greater activity. At a higher nitrogen level (210 ppm) apical dominance was markedly reduced but the resulting outgrowth of the lateral buds increased the inhibiting capacity of the shoot, limiting root bud response. When the main shoot was decapitated the degree to which root bud growth was suppressed by a given number of lateral shoots was inversely related to the nitrogen supply. Inhibition of the root buds by the lateral shoots could be significantly reduced by growing the plants initially at a low nitrogen level so that growth of the lateral buds was arrested. A subsequent increase in the nitrogen supply strongly promoted the growth of the roots buds, some of which were sufficiently released from inhibition to emerge as leafy shoots.

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

Leakage of K, Mg, Cl, Ca and Mn from imbibing seeds, grains and isolated seed parts

1991 ◽  
Vol 1 (4) ◽  
pp. 229-233 ◽  
Author(s):  
John N. A. Lott ◽  
Vandy Cavdek ◽  
Joanne Carson
Keyword(s):  
Neutron Activation Analysis ◽  
Instrumental Neutron Activation Analysis ◽  
Activation Analysis ◽  
The Other ◽  
Mineral Nutrient ◽  
Species Comparisons ◽  
Five Elements ◽  
Nutrient Reserves ◽  
Seed Coats ◽  
Storage Reserves

AbstractInstrumental neutron activation analysis (NAA) was used to quantify the amounts of K, Mg, Cl, Ca and Mn leaked into water from imbibing dry seeds, dry fruits and isolated seed parts. A number of intact monocot and dicot dry seeds or fruits were studied as were some isolated parts such as testa, endosperm and embryo. All samples studied leaked detectable amounts of the five elements measured but the amounts leaked varied greatly. In most cases K was leaked in greater amounts than the other elements while Mn was leaked least. The leakage of Ca was highest from isolated seed coats and from mericarps of three umbelliferous species. Comparisons of the amount of element leaked with the total amount of that element present in the starting material showed that leakage, especially of K, represents a substantial loss of mineral nutrient reserves. The degree of leakage of elements did not appear to be closely related to the types of organic storage reserves present.

Response of alfalfa and sugar beet to field dodder (Cuscuta campestris Yunck.) parasitism: a physiological and anatomical approach

2019 ◽  
Vol 99 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Marija Saric-Krsmanovic ◽  
Dragana Bozic ◽  
Ljiljana Radivojevic ◽  
Jelena Gajic Umiljendic ◽  
Sava Vrbnicanin
Keyword(s):  
Sugar Beet ◽  
Mineral Nutrients ◽  
Flowering Plant ◽  
Mineral Nutrient ◽  
Vascular Bundles ◽  
Nutrient Contents ◽  
Cuscuta Campestris ◽  
Organic Nutrients ◽  
Leaf Parameters ◽  
Anatomical Parameters

The physiological and anatomical impact of field dodder (Cuscuta campestris Yunck.) on alfalfa and sugar beet was examined under controlled conditions. The following parameters were checked: physiological — content of pigments (chlorophyll a, chlorophyll b, and carotenoids) and mineral nutrients: nitrogen, phosphorus, potassium, and percent of organic and mineral nutrients; and anatomical — thickness of the epidermis and cortex, diameter of the stem and central cylinder of alfalfa plants, diameter of tracheids and phloem cells, area of xylem and phloem, and hydraulic conductance of petiole bundles in petiole vascular bundles of sugar beet plants. Leaf parameters were also measured on both host plants: thickness of upper and underside leaf epidermis, thickness of palisade, spongy and mesophyll tissue, and diameter of vascular bundle cells. Pigments content and anatomical parameters were measured 7, 14, 21, 28, 35, and 42 d after infestation (DAI), while mineral nutrient contents were determined 20 and 40 DAI. Field dodder caused a significant reduction in pigments content in infested alfalfa (15%–68%) and sugar beet plants (1%–54%). The results obtained in this study confirmed that this parasitic flowering plant has a strong effect on most anatomical parameters of the stem and leaf of alfalfa and leaf and petiole of sugar beet. Also, it was revealed that field dodder increased the contents of N, P2O5, K2O, and organic nutrients in infested alfalfa plants, while infested sugar beet plants had higher contents of N and organic nutrients compared with non-infested plants.

NODULATION RESPONSES OF TWO NEAR ISOGENIC LINES OF THE SOYBEAN

1957 ◽  
Vol 3 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Francis E. Clark
Keyword(s):  
Amino Acids ◽  
Ascorbic Acid ◽  
Nutrient Solution ◽  
The Other ◽  
Negative Response ◽  
Sand Culture ◽  
Near Isogenic Lines ◽  
Soybean Line ◽  
Sand Cultures ◽  
Different Soils

Nodulation responses and certain other characteristics of a mutant soybean line highly recalcitrant to nodulation were compared with those of a nodulating sister line. Roots of the two lines were found to harbor equal numbers of rhizobia. Stem graftings to provide top growths of one line on roots of the other failed to alter the distinctive nodulation responses of rootstocks. Ascorbic acid contents in the two lines were identical, both in the tops and in the roots, although contents in tops greatly exceeded those found in roots. Chromatographic studies on the amino acids in seed hydrolyzates and in alcoholic extracts of seedlings showed no differences between the two lines either in kind or quantities of amino acids. In a survey of stock rhizobia for cultures effective on the nonnodulating line, bacteria were discovered which formed nodules on such soybeans growing in sand and nutrient solution. Isolates from these nodules again yielded effective nodulation on plants in sand culture, but gave no nodulation whatsoever on plants growing in soil. This negative response was confirmed in three different soils. Admixtures of soil and of miscellaneous materials with sand were employed to alter nodulation responses from those shown in sand cultures.

scholarly journals High Sucrose Levels and Abnormal Enzyme Activity as a Function of Nutritional Stress in Sugarcane

1969 ◽  
Vol 51 (4) ◽  
pp. 325-333
Author(s):  
Alex G. Alexander
Keyword(s):  
Nutrient Deficiency ◽  
Critical Factor ◽  
Nutritional Stress ◽  
Nutrient Supply ◽  
Oxidative Enzymes ◽  
Sand Culture ◽  
High Level ◽  
To Receive ◽  
High Sucrose ◽  
Nitrogen Phosphorus

Deficiencies of nitrogen, phosphorus, potassium, and calcium were gradually induced in sugarcane grown by sand culture. There were three objectives: 1, To determine whether nutritional stress in general is a means of inducing higher sucrose production; 2, to determine whether sucrose increases can be triggered without reaching nutrient-deficiency levels which would reduce tonnage; and 3, to ascertain whether increased sucrose production can be traced to common behavior patterns of hydrolytic and oxidative enzymes. All plants received a moderately high level of all nutrients until 14 weeks of age. Thereafter, individual nutrients were gradually lowered at intervals of 2 weeks, while control plants continued to receive the original levels. All plants subjected to nutritional stress accumulated higher leaf sucrose than control plants, regardless of the nutrient withheld. In each instance sucrose increases were recorded before nutrient supply had reached deficiency proportions. General nutritional stress thus appears to trigger variations in sugar level, with nutritional imbalance rather than actual deficiency being a critical factor. All plants under nutritional stress revealed a concurrent suppression of amylase as sucrose increased. Peroxidase was greatly stimulated by all nutritional treatments. Phosphatase was suppressed by decreasing nitrate and phosphorus, but was generally unaffected by the potassium and calcium treatments. Several distinct mechanisms of increased sucrose formation are indicated by the enzyme data. Sensitivity of amylase to changing nutrient supply is discussed from the standpoint of a possible indicator of approaching deficiency.

The Influence of Heavy Metals and Mineral Nutrient Supply on Bituminaria bituminosa

2007 ◽  
Vol 184 (1-4) ◽  
pp. 335-345 ◽  
Author(s):  
David J. Walker ◽  
M. Pilar Bernal ◽  
Enrique Correal
Keyword(s):  
Heavy Metals ◽  
Nutrient Supply ◽  
Mineral Nutrient ◽  
Bituminaria Bituminosa
Sign in / Sign up

Export Citation Format

Share Document