Nitrogen supply, apical dominance and branch growth inPinus radiata

1971 ◽  
Vol 34 (1) ◽  
pp. 515-517 ◽  
Author(s):  
G. M. Will
Keyword(s):  
Apical Dominance ◽  
Nitrogen Supply ◽  
Branch Growth

Environmental control of apical dominance in Phaseolus vulgaris

1973 ◽  
Vol 51 (2) ◽  
pp. 293-299 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Water Stress ◽  
Phaseolus Vulgaris ◽  
Light Intensity ◽  
Nitrogen Content ◽  
Apical Dominance ◽  
Growth Response ◽  
Environmental Control ◽  
Nitrogen Supply ◽  
Soluble Nitrogen ◽  
Bud Growth

When seedlings of Phaseolus vulgaris were grown under controlled conditions at a light intensity of 3200 ft-c, 60% relative humidity, and at nitrogen levels of 5.25, 52.5, and 210 ppm, growth of the buds at the cotyledonary node, which served as a measure of apical dominance, showed a positive correlation with the nitrogen supply and with the soluble nitrogen content of the hypocotyl. Increasing the nitrogen supply to 420 ppm caused a proportionate increase in soluble nitrogen content but no additional bud growth response. That the growth response was limited by water supply was shown by growing plants at 420 ppm nitrogen and relative humidities of 30, 60, and 90%. Each reduction in water stress, as measured by leaf relative turgidity, caused a highly significant increase in growth of the cotyledonary buds. Under high nitrogen, low water stress conditions, bud growth was markedly inhibited by reduction of the light intensity from 3200 to 700 ft-c.These results support the concept of nutrient competition as a major factor in the mechanism of apical dominance and also suggest that conflicting reports on the effect of externally applied growth-regulating substances on lateral bud inhibition may be due partly to environmentally induced differences in nutritional status of the experimental plants.

Apical dominance in the rhizome of Agropyron repens: the influence of nitrogen and humidity on the translocation of 14C-labelled assimilates

1979 ◽  
Vol 57 (11) ◽  
pp. 1229-1235 ◽  
Author(s):  
F. A. Qureshi ◽  
G. I. McIntyre
Keyword(s):  
Protein Synthesis ◽  
Apical Dominance ◽  
Nitrogen Supply ◽  
Limiting Factor ◽  
High Humidity ◽  
Bud Size ◽  
Apical Node ◽  
Bud Growth ◽  
Stimulation Of ◽  
Agropyron Repens

When the buds on the rhizome of Agropyron repens were released from apical dominance either by increasing the nitrogen supply or by raising the humidity around the rhizome, their uptake of 14C-labelled assimilates from the parent shoot was significantly increased. While this effect was produced by each treatment when applied separately, the uptake of 14C by the buds was more than twice as great when both treatments were combined. The 14C level in the rhizome was also increased, this effect being greater and more consistent in response to the change in humidity than to the increased nitrogen supply. In the controls, uptake of the labelled assimilates was greatest by the bud at the apical node and decreased basipetally along the rhizome. This pattern was not correlated with bud size and probably resulted from a basipetal gradient of declining metabolic activity. Increasing the humidity around the rhizome altered this pattern, preferentially promoting the uptake of the label by the bud at the subapical node. To account for the stimulation of bud growth by high humidity when nitrogen was apparently the limiting factor, it is postulated that the increase in water potential of the bud may accelerate protein synthesis, thereby enhancing the bud's capacity to compete for the limiting nitrogen supply.

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 Nitrogen and Humidity on Rhizome Bud Growth and Glyphosate Translocation in Quackgrass (Agropyron repens)

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Gordon I. McIntyre ◽  
Andrew I. Hsiao
Keyword(s):  
Apical Dominance ◽  
Growth Response ◽  
Dry Weight ◽  
Nitrogen Supply ◽  
Weight Basis ◽  
High Humidity ◽  
Apical Node ◽  
Bud Growth ◽  
Rhizome Bud ◽  
Agropyron Repens

When buds on the rhizome of quackgrass [Agropyron repens(L.) Beauv.] were released from apical dominance either by increasing the nitrogen supply to the parent shoot (from 5.25 to 210 ppm) or by raising the humidity around the rhizome (from 55 to 100%), the growth response of the buds was closely correlated with their uptake of foliar-applied14C-labeled glyphosate [N-(phosphonomethyl] glycine]. The14C level in the buds, expressed on a dry-weight basis, was greatest in the youngest, most rapidly growing bud at the apical node and decreased in successively older buds along the rhizome. A similar gradient was shown by the14C content of the associated rhizome nodes. The high-humidity treatment also increased the total amount of14C that was translocated into the rhizome, whereas increasing the nitrogen supply, while promoting14C uptake by the buds, markedly reduced the amount in the rhizome nodes and in other parts of the plant. This nitrogen-induced reduction in translocation was associated with a reduction of about 30% in uptake of the herbicide by the treated leaves.

Nitrogen distribution in young Norway spruce (Picea abies) trees as affected by pedospheric nitrogen supply

1997 ◽  
Vol 101 (4) ◽  
pp. 764-769 ◽  
Author(s):  
Heike Stoermer ◽  
Bettina Seith ◽  
Ulrike Hanemann ◽  
Eckhard George ◽  
Heinz Rennenberg
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Nitrogen Supply ◽  
Nitrogen Distribution

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.

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