Photosynthetic activity, pigment composition and antioxidative response of two mustard (Brassica juncea) cultivars differing in photosynthetic capacity subjected to cadmium stress

2007 ◽  
Vol 164 (5) ◽  
pp. 601-610 ◽  
Author(s):  
Mohammad Mobin ◽  
Nafees A. Khan
Keyword(s):  
Brassica Juncea ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Cadmium Stress ◽  
Pigment Composition ◽  
Antioxidative Response

Chlorophyll changes, photosynthesis, and ultrastructure of chloroplasts in Albugo candida induced "green islands" on detached Brassica juncea cotyledons

1968 ◽  
Vol 46 (10) ◽  
pp. 1229-1234 ◽  
Author(s):  
Howard Harding ◽  
Paul H. Williams ◽  
Sharon S. McNabola
Keyword(s):  
Chlorophyll Content ◽  
Brassica Juncea ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Soluble Fraction ◽  
Albugo Candida ◽  
Chlorophylls A And B ◽  
Stroma Lamellae ◽  
Green Island

Brassica juncea cotyledons were detached from the plant 3 days after inoculation with Albugo candida. Changes in chlorophyll content of infected and noninfected tissue were determined over a 4-day period, during which time distinct "green islands" developed. Following incubation with glycine-2-14C in the light, radioactivity was detected in chlorophylls a and b of both infected and noninfected tissue. Both infected and noninfected tissue fixed 14CO2 in the light during the 4 days after detachment. Most of the incorporated activity was in the 70% ethanol-soluble fraction. At 4 days after detachment, "green islands" fixed 5 times more 14CO2 in the light than noninfected tissue while both types of tissue fixed about the same amount in the dark. Photosynthesis per mole of chlorophyll fell at the same rate in "green island" and noninfected tissue. The maintenance of chlorophyll and continued photosynthetic activity in "green islands" paralleled delayed chloroplast breakdown. "Green island" chloroplasts still had intact grana and relatively small osmiophilic globules 96 h after detachment. In noninfected tissue, grana began to break down and osmiophilic globules increased in size 48 h after detachment. At 96 h after detachment, little grana structure remained and chloroplasts contained greatly enlarged osmiophilic globules interspersed with strands of stroma lamellae. Tissue treated with kinetin responded in essentially the same way as "green island" tissue. Chlorophyll content and photosynthetic capacity were maintained and chloroplast breakdown was delayed.

Detection of photosynthetic activity under cadmium stress by measurement of the red and far-red chlorophyll fluorescence

2011 ◽  
Vol 32 (15) ◽  
pp. 4233-4248 ◽  
Author(s):  
Jaouhra Cherif ◽  
Najoua Derbel ◽  
Mohamed Nakkach ◽  
Chamseddine Mediouni ◽  
Hubertus Von Bergmann ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Activity ◽  
Cadmium Stress

Photosynthetic Activity of Leaves of Pinus radiata and Nothofagus fusca After 1 Year of Growth at Elevated CO2

1996 ◽  
Vol 23 (5) ◽  
pp. 623 ◽  
Author(s):  
KP Hogan ◽  
D Whitehead ◽  
J Kallarackal ◽  
JG Buwalda ◽  
J Meekings ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Pinus Radiata ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Radiata Pine ◽  
Rubisco Activity ◽  
Co2 Partial Pressure ◽  
Partial Pressures ◽  
The Difference ◽  
Triose Phosphate Utilisation

Radiata pine (Pinus radiata D.Don) and red beech (Nothofagus fusca (Hook. f.) Oerst.) were grown for over 1 year at elevated (ELEV, 64 Pa) and ambient (AMB, 38 Pa) CO2 partial pressure in open-top chambers. Springtime measurements of overwintering leaves showed that light- and CO2-saturated photosynthetic rates (Amax) of pine leaves were similar for the two treatments (AMB: 6.7 � 1.08 μmol m-2 s-1, mean � 1 s.e.; ELEV: 6.6 � 0.47) but, for beech leaves, Amax was greater for AMB plants (8.8 � 0.90 μmol m-2 s-1) than for ELEV plants (6.10 � 0.71). Summertime measurements of leaves grown that spring showed that for pine, Amax was similar in the two CO2 treatments (AMB 14.9 μmol m-2 s-1 � 0.80; ELEV: 13.5 � 1.9) while, for beech, Amax was higher in AMB plants (21.0 � 1.1) than in ELEV plants (17.2 � 1.9), although the difference was not statistically significant. These results indicate downregulation of photosynthetic capacity of beech but not pine. Vcmax did not differ between treatments within species, suggesting that there was no acclimation of rubisco activity. Triose phosphate utilisation limitation may have contributed to the downregulation of Amax in beech. For pine, photosynthesis at treatment CO2 partial pressures was greater in ELEV plants in both spring and summer. For beech measured at treatment CO2 partial pressures, photosynthesis was greater in ELEV plants in summer, but was similar between treatments in the springtime.

scholarly journals Enhanced Relative Electron Transport Rate Contributes to Increased Photosynthetic Capacity in Autotetraploid Pak Choi

2020 ◽  
Vol 61 (4) ◽  
pp. 761-774 ◽  
Author(s):  
Changwei Zhang ◽  
Huiyu Wang ◽  
Yuanyuan Xu ◽  
Shuning Zhang ◽  
Jianjun Wang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Powdery Mildew Resistance ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Electron Transport Rate ◽  
Ectopic Expression ◽  
Transport Rate ◽  
Pak Choi ◽  
Relative Electron Transport Rate ◽  
Relative Electron

Abstract Autopolyploids often show growth advantages over their diploid progenitors because of their increased photosynthetic activity; however, the underlying molecular basis of such mechanism remains elusive. In this study, we aimed to characterize autotetraploid pak choi (Brassica rapa ssp. chinensis) at the physiological, cellular and molecular levels. Autotetraploid pak choi has thicker leaves than its diploid counterparts, with relatively larger intercellular spaces and cell size and greater grana thylakoid height. Photosynthetic data showed that the relative electron transport rate (rETR) was markedly higher in autotetraploid than in diploid pak choi. Transcriptomic data revealed that the expressions of genes involved in ‘photosynthesis’ biological process and ‘thylakoids’ cellular component were mainly regulated in autotetraploids. Overall, our findings suggested that the increased rETR in the thylakoids contributed to the increased photosynthetic capacity of autotetraploid leaves. Furthermore, we found that the enhanced rETR is associated with increased BrPetC expression, which is likely altered by histone modification. The ectopic expression of BrPetC in Arabidopsis thaliana led to increased rETR and biomass, which were decreased in BrPetC-silenced pak choi. Autotetraploid pak choi also shows altered hormone levels, which was likely responsible for the increased drought resistance and the impaired powdery mildew resistance of this lineage. Our findings further our understanding on how autotetraploidy provides growth advantages to plants.

scholarly journals Activity of the Photosynthetic Apparatus in Phaseolus vulgaris L. Leaves Under the Cadmium Stress

2018 ◽  
Vol 47 (2) ◽  
pp. 405-411
Author(s):  
Joanna PUŁA ◽  
Beata BARABASZ-KRASNY ◽  
Andrzej LEPIARCZYK ◽  
Peiman ZANDI ◽  
Katarzyna MOŻDŻEŃ
Keyword(s):  
Phaseolus Vulgaris ◽  
Photosynthetic Activity ◽  
Chemical Elements ◽  
Cadmium Concentration ◽  
Photosynthetic Apparatus ◽  
Cadmium Stress ◽  
Cadmium Nitrate ◽  
Phaseolus Vulgaris L ◽  
Cadmium Ions ◽  
Bean Leaves

The development of civilisation, urbanisation and industrialisation cause to ever increasing contamination of the natural environment. Cadmium belongs to this group of chemical elements, which represent a serious threat, not only for the proper development of plants but also for the health of humans and animals. Hence, the interest of scientists in the toxic effects of this kind chemical elements on the various life functions of organisms. The aim of this study was to investigate the effect of cadmium nitrate aqueous solutions on photosynthetic activity and degree of disorganisation of cell membranes in leaves of common bean (Phaseolus vulgaris L. cv. ‘Laurina’). A fully formed second leaves were wetted with cadmium solutions nitrate (Cd(NO3)2) at concentrations of 5 and 10 mM. With the increasing of cadmium concentration and time of its application (20, 40, 60 min and 24 h), the changes in the fluorescence of bean leaves were observed. Under the influence of cadmium ions, damage occurred both on the edge and the central part of the leaves, and then the whole surface. The highest changes of the chlorophyll fluorescence values were observed after 24 h of application the aqueous cadmium solutions. Use of SPAD chlorophyll Meter, the reduction of chlorophyll content was noticed over time. The flow of electrolytes from the bean leaves was increased with the time and concentration of applied cadmium compounds.

scholarly journals Transient Heat Waves May Affect the Photosynthetic Capacity of Susceptible Wheat Genotypes Due to Insufficient Photosystem I Photoprotection

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 282 ◽  
Author(s):  
Erik Chovancek ◽  
Marek Zivcak ◽  
Lenka Botyanszka ◽  
Pavol Hauptvogel ◽  
Xinghong Yang ◽  
...  
Keyword(s):  
Heat Wave ◽  
Photosystem I ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Heat Waves ◽  
Transparent Plastic ◽  
Wheat Varieties ◽  
Acceptor Side ◽  
Negative Effect ◽  
Photosynthetic Responses

We assessed the photosynthetic responses of eight wheat varieties in conditions of a simulated heat wave in a transparent plastic tunnel for one week. We found that high temperatures (up to 38 °C at midday and above 20 °C at night) had a negative effect on the photosynthetic functions of the plants and provided differentiation of genotypes through sensitivity to heat. Measurements of gas exchange showed that the simulated heat wave led to a 40% decrease in photosynthetic activity on average in comparison to the control, with an unequal recovery of individual genotypes after a release from stress. Our results indicate that the ability to recover after heat stress was associated with an efficient regulation of linear electron transport and the prevention of over-reduction in the acceptor side of photosystem I.

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