Photoassimilate Translocation

2018 ◽  
pp. 227-251 ◽  
Author(s):  
Rashmi Shakya ◽  
Manju A. Lal
Keyword(s):  
Photoassimilate Translocation

A general method for determining translocation velocity in Laminariales

1981 ◽  
Vol 59 (2) ◽  
pp. 132-136 ◽  
Author(s):  
Richard G. Buggeln
Keyword(s):  
Pulse Method ◽  
Blade Surface ◽  
Laminaria Digitata ◽  
Incubation Chamber ◽  
Photoassimilate Translocation ◽  
Alaria Esculenta ◽  
Meristematic Region ◽  
Translocation Velocity ◽  
Distance Transport ◽  
General Method

The nondestructive pulse method for studying 14C-labelled photoassimilate translocation in Alaria esculenta has been adapted for species of Laminariales with flat, thick blades, in this case, Laminaria digitata. A 1-h pulse of [14C]bicarbonate(25 μCi) was applied to one side of the blade surface via a 12 mm diameter by 22 mm high, closed cylindrical incubation chamber. The upper 20-mm closed portion of the chamber was removed after the incubation period, the lower 2-mm open portion remained glued to the blade surface during the subsequent translocation period. A Geiger-Müller (G-M) detector probe with a 50 mm diameter end-window was used to measure the disappearance of radioactive organic matter from the pulsed region over the next 11–12 days. Accurate monitoring of the movement of 14C-labelled solutes through the cortex and into the medulla was confounded by changing absorption of radioactivity by the cortex. Uniform absorption was achieved once the translocatable radioactivity reached the medullary conducting cells (sieve filaments). Thus arrival and accumulation of 14C-labelled assimilate in the blade sink (meristem) was reliably measured with the G-M probe. For Laminaria digitata, the translocation velocity of the moving solute front was 1.7 cm∙h−1. The specific mass transfer of carbon was estimated at 0.4 mg C∙week−1∙mm−2 cross-sectioned medulla. Fifty-seven percent of assimilated carbon was exported in 10 days; 97% of the 14C remaining in the source was in insoluble matter and 3% was in soluble matter. Cutting sieve filaments on the sink side of the incubation chamber did not stop short distance transport through the cortex, but significant 14C-labelled photoassimilate was apparently unable to be re-routed around the cut as no radioactivity was detected in the sink area, the meristematic region at the base of the blade.

scholarly journals Environmental Effects on Dynamics of Fruit Growth and Photoassimilate Translocation in Tomato Plants. (3). Effect of Salt Stress.

2001 ◽  
Vol 39 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Takuya ARAKI ◽  
Masaharu KITANO ◽  
Kunio OKANO ◽  
Satoshi YOSHIDA ◽  
Toshihiko EGUCHI
Keyword(s):  
Salt Stress ◽  
Environmental Effects ◽  
Fruit Growth ◽  
Tomato Plants ◽  
Photoassimilate Translocation

scholarly journals Photoassimilate translocation in the petiole ofCyclamenandPrimulais independent of lateral retrieval

1997 ◽  
Vol 48 (5) ◽  
pp. 1087-1094 ◽  
Author(s):  
Eckhard Grimm ◽  
Siegfried Jahnke ◽  
Katrin Rothe
Keyword(s):  
Photoassimilate Translocation

Nitrogen supply in combination of nitrate and ammonium enhances harnessing of elevated atmospheric CO2 through improved nitrogen and carbon metabolism in wheat (Triticum aestivum)

2020 ◽  
Vol 71 (2) ◽  
pp. 101
Author(s):  
Muhammad Asif ◽  
Seray Zora ◽  
Yasemin Ceylan ◽  
Raheela Rehman ◽  
Levent Ozturk
Keyword(s):  
Triticum Aestivum ◽  
Biomass Production ◽  
Plant Biomass ◽  
Triticum Aestivum L ◽  
Co2 Assimilation ◽  
Elevated Atmospheric Co2 ◽  
N Supply ◽  
Photoassimilate Translocation ◽  
Net Co2 Assimilation ◽  
N Metabolism

Elevated carbon dioxide (e-CO2) levels from ambient (a-CO2) enhance plant biomass production and yield. However, this response is highly dependent on the availability and possibly the form of nitrogen (N) supply to plants. This study aimed to investigate changes in C and N metabolism of wheat (Triticum aestivum L.) in response to e-CO2 and N source. e-CO2 enhanced net CO2 assimilation but at highly variable rates depending on the form of N supply. Under e-CO2, net CO2 assimilation rate was in the order NO3– > NH4NO3 > NH4+ > urea. Plants supplied with ammonium and nitrate (i.e. NH4NO3) performed better in terms of biomass production and expressed a higher biomass enhancement ratio by e-CO2 than plants receiving sole applications of NO3–, NH4+ or urea. Supply of NH4NO3 also resulted in lower intercellular CO2, higher photoassimilate translocation to roots and lower accumulation of free amino acids than other N forms, indicating a better exploitation of the e-CO2 environment. Our results conclude that major physiological pathways of photosynthesis and protein and carbohydrate metabolism are differentially influenced by e-CO2 depending on the source of N supply. A balanced supply of NO3– and NH4+ to plant roots is the key to harnessing e-CO2 while minimising its adverse effects on quality of the produce.

scholarly journals Sugarcane Plant Growth and Physiological Responses to Soil Salinity during Tillering and Stalk Elongation

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 608
Author(s):  
Duli Zhao ◽  
Kai Zhu ◽  
Aliya Momotaz ◽  
Xinxin Gao
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Soil Salinity ◽  
Salt Concentration ◽  
High Salt ◽  
Water Soluble ◽  
High Salt Concentration ◽  
Sugarcane Plant ◽  
Soil Salt ◽  
Photoassimilate Translocation

A pot study was conducted to investigate influences of salinity on sugarcane (Saccharum spp.) plant growth, leaf photosynthesis, and other physiological traits during tillering and stalk elongation. Treatments included two commercial sugarcane cultivars (Canal Point (CP) 96-1252 and CP 00-1101) and an Erianthus with five different soil salt concentrations (0 [Control], 38, 75, 150, and 300 mM of NaCl added). Growth (tillers, plant height, and nodes) and physiological (leaf net photosynthetic rate [Pn], stomatal conductance [gs], intercellular CO2 concentration, and leaf water soluble sugar concentrations) characters were determined during the experiment. Responses of sugarcane growth, photosynthesis, and photoassimilate translocation to salinity depended on soil salt concentration. Plant height was the most sensitive while the number of nodes was the most tolerant to soil salinity among the three growth traits measured. CP 96-1252 differed from CP 00-1101 significantly in response of shoot:root ratio to high salt concentration. Leaf Pn of plants treated with the 38 mM salt did not differ from that of the control plant, but plants treated with the 75, 150, and 300 mM salt had 12.7, 18.7, and 35.3% lower leaf Pn, respectively, than the control. The low leaf Pn due to salinity was associated with not only the decrease in gs, but also the non-stomatal factors. Results of leaf sugar composition and concentrations revealed that high salt concentration also depressed photoassimilate translocation from leaves to other plant tissues. These findings are important for better understanding of some physiological mechanisms of salinity influence on sugarcane growth and yields.

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