scholarly journals Photosynthetic Activity of Four Florist Azalea Cultivars

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 682a-682
Author(s):  
C. Bellert ◽  
F. Gauthier ◽  
B. Dansereau
Keyword(s):  
Open System ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Dark Respiration ◽  
Model Parameters ◽  
Whole Plant ◽  
Leaf Level ◽  
Plant Level ◽  
Photosynthetic Assimilation ◽  
The Individual

The photosynthetic activity of four Rhododendron simsii cultivars `Dorothy Gish', `Paloma', `White Gish', and `Gloria' were studied at both the individual leaf level using a portable photosynthesis system (closed), or at the whole-plant level using assimilation chambers (semi-open system). Net photosynthetic assimilation curves in response to light in both systems will be established. The experimental points obtained will be adjusted to a photosynthetic model as described in the literature. The model parameters [original efficiency (α) dark respiration (Rd), maximum photosynthetic capacity to saturated light (Pmax)] will be presented. The evolution of these parameters will be presented as a function of the various stages of development. Also a comparison of the four cultivars will be shown.

Carbon Production and Utilization in Cotton: Inferences From a Carbon Budget

1980 ◽  
Vol 7 (5) ◽  
pp. 539 ◽  
Author(s):  
GA Constable ◽  
HM Rawson
Keyword(s):  
Carbon Budget ◽  
Carbon Fixation ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
General Hypothesis ◽  
Carbon Production ◽  
Single Leaf ◽  
Whole Plant ◽  
Plant Level

A carbon budget for cotton plants at the single leaf, node and whole plant level was constructed using data from four glasshouse experiments. Data were collected on leaf expansion and dry weight growth, net photosynthesis, dark respiration of leaves and stems and on responses of photosynthesis to light in tissues of different age. The potential export of carbon by leaves was calculated as daily net photosynthesis less requirements for growth and dark respiration. The carbon budget for the single leaf showed that the leaf's maximum requirement occurred 7-8 days after unfolding, at the same time as it became a net carbon exporter. Dark respiration used most carbon at days 12-15 but even then the amount was only about 10% of the carbon fixation by the leaf during the day. Potential carbon export reached a peak in 22-day-old leaves, approximating 1 mg C cm-2 day -1 on a sunny day. The main finding from the budget was that carbon production and its utilization by bolls is out of phase both at the node and whole plant level which necessitates considerable movement of carbon among nodes and into and out of storage. This finding was confirmed in a study using 14CO2 which, while supporting the general hypothesis that the plant's carbon is fed into a pool available to all organs, indicated that there are preferred links between node positions in vertical alignment.

scholarly journals The contribution of PIP2-type aquaporins to photosynthetic response to increased vapour pressure deficit

2021 ◽  
Author(s):  
D Israel ◽  
S Khan ◽  
C R Warren ◽  
J J Zwiazek ◽  
T M Robson
Keyword(s):  
Vapour Pressure Deficit ◽  
Air Humidity ◽  
Wild Type ◽  
Knockout Mutant ◽  
Evaporative Demand ◽  
Co2 Transport ◽  
Whole Plant ◽  
Knockout Mutants ◽  
Leaf Level ◽  
Low Humidity

Abstract The roles of different plasma membrane aquaporins (PIPs) in leaf-level gas exchange of Arabidopsis thaliana were examined using knockout mutants. Since multiple Arabidopsis PIPs are implicated in CO2 transport across cell membranes, we focused on identifying the effects of the knockout mutations on photosynthesis, and whether they are mediated through the control of stomatal conductance of water vapour (gs), mesophyll conductance of CO2 (gm) or both. We grew Arabidopsis plants in low and high humidity environments and found that the contribution of PIPs to gs was larger under low air humidity when the evaporative demand was high, whereas any effect of lacking PIP function was minimal under higher humidity. The pip2;4 knockout mutant had 44% higher gs than the wild type plants under low humidity, which in turn resulted in an increased net photosynthetic rate (Anet). We also observed a 23% increase in whole-plant transpiration (E) for this knockout mutant. The lack of functional AtPIP2;5 did not affect gs or E, but resulted in homeostasis of gm despite changes of humidity, indicating a possible role in regulating CO2 membrane permeability. CO2 transport measurements in yeast expressing AtPIP2;5 confirmed that this aquaporin is indeed permeable to CO2.

scholarly journals How Herbivore Browsing Strategy Affects Whole-Plant Photosynthetic Capacity

2017 ◽  
Vol 79 (4) ◽  
pp. 772-787 ◽  
Author(s):  
E. Penelope Holland ◽  
Julie Mugford ◽  
Rachelle N. Binny ◽  
Alex James
Keyword(s):  
Photosynthetic Capacity ◽  
Whole Plant

scholarly journals Ontogenetic shift in the scaling of dark respiration with whole-plant mass in seven shrub species

2009 ◽  
Vol 24 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Youhong Peng ◽  
Karl J. Niklas ◽  
Peter B. Reich ◽  
Shucun Sun
Keyword(s):  
Dark Respiration ◽  
Ontogenetic Shift ◽  
Shrub Species ◽  
Whole Plant

scholarly journals Leaf-level photosynthetic capacity dynamics in relation to soil and foliar nutrients along forest–savanna boundaries in Ghana and Brazil

2018 ◽  
Vol 38 (12) ◽  
pp. 1926-1926
Author(s):  
Agne Gvozdevaite ◽  
Imma Oliveras ◽  
Tomas Ferreira Domingues ◽  
Theresa Peprah ◽  
Mickey Boakye ◽  
...  
Keyword(s):  
Photosynthetic Capacity ◽  
Foliar Nutrients ◽  
Leaf Level

Common Cocklebur (Xanthium strumarium) Resistance to Selected ALS-Inhibiting Herbicides

1997 ◽  
Vol 11 (2) ◽  
pp. 241-247 ◽  
Author(s):  
Christy L. Sprague ◽  
Edward W. Stoller ◽  
Loyd M. Wax
Keyword(s):  
Acetolactate Synthase ◽  
Cross Resistance ◽  
Xanthium Strumarium ◽  
Laboratory Studies ◽  
Whole Plant ◽  
Plant Level

Five biotypes of common cocklebur that were not controlled with acetolactate synthase (ALS)-inhibiting herbicides were tested in greenhouse and laboratory studies to determine the magnitude of resistance and cross-resistance to four ALS-inhibiting herbicides. In vivo inhibition of ALS was also evaluated. Based on phytotoxicity, all five ALS-resistant biotypes of common cocklebur were > 390 times more resistant than the susceptible biotype to imazethapyr. However, only four of these biotypes were also resistant to another imidazolinone, imazaquin. Two biotypes were cross-resistant to the sulfonylurea, chlorimuron, and the triazolopyrimidine sulfonanilide, NAF-75. One biotype demonstrated intermediate susceptibility to imazaquin, chlorimuron, and NAF-75. In all cases, the resistance exhibited at the whole plant level was associated with an insensitive ALS.

Sucrose Transporter Gene AtSUC4 Responds to Drought Stress by Regulating the Sucrose Distribution and Metabolism in Arabidopsis thaliana

2013 ◽  
Vol 765-767 ◽  
pp. 2971-2975 ◽  
Author(s):  
Xue Gong ◽  
Ming Li Liu ◽  
Li Jun Zhang ◽  
Wei Liu ◽  
Che Wang
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Plant Stress ◽  
Homozygous Mutation ◽  
Transporter Gene ◽  
Wild Type ◽  
Sucrose Transporters ◽  
Whole Plant ◽  
Plant Stress Tolerance ◽  
Plant Level

Sucrose transporters (SUCs or SUTs) are considered as the important carriers and responsible for the loading, unloading and distribution of sucrose, but at present there is no report that SUCs are involved in sucrose distribution and metabolism under drought stress at the whole-plant level. AtSUC4, as the unique member of SUT4-clade inArabidopsis thaliana, may be important for plant stress tolerance. Here, by analyzing two homozygous mutation lines ofAtSUC4(Atsuc4-1andAtsuc4-2), we found drought stress induced higher sucrose, lower fructose and glucose contents in shoots, and lower sucrose, higher fructose and glucose contents in roots of these mutants compared with the wild-type (WT), leading to an imbalance of sucrose distribution, fructose and glucose (sucrose metabolites) accumulation changes at the whole-plant level. Thus we believe thatAtSUC4regulates sucrose distribution and metabolism in response to drought stress.

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