scholarly journals Chilling tolerance in Zizania latifólia

2016 ◽  
Vol 34 (1) ◽  
pp. 39-45
Author(s):  
Zihong Ye ◽  
Haifeng Cui ◽  
Xinxin An ◽  
Xiaoping Yu
Keyword(s):  
Cold Stress ◽  
Heat Dissipation ◽  
Chilling Tolerance ◽  
Photochemical Quenching ◽  
Electric Transport ◽  
Zizania Latifolia ◽  
Critical Pathways ◽  
Photosynthesis Inhibition ◽  
Non Photochemical Quenching ◽  
Latent Activity

ABSTRACT: The tumescent stems of Zizania latifolia are consumed as vegetable in southern and eastern Asia. This study aimed to compare photosynthesis and chilling tolerance parameters between two well-known Zizania latifolia cultivars: Longjiao 2 and Zhejiao 911, which are chilling tolerant and sensitive, respectively. We found that severe cold stress induced photosynthesis inhibition (5°C) resulted from non-stomatal factors. However, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of the cultivar Longjiao 2 were higher than that of Zhejiao 911 with more gradual variations. Six parameters of chlorophyll fluorescence including latent activity of PSII (Fv/F0), efficiency of primary photochemistry (Fv/Fm), photochemical quenching coefficient (qP), non-photochemical quenching coefficient (qN), quantum yield of electric transport (Yield) and the ratio of electric transport at PSII (ETR) were analyzed in the two cultivars. We found that Longjiao 2 had significantly higher Fv/Fm and qN than Zhejiao 911 while qP values were only slightly different for the two lines at severe cold stress. In our experiments, Yield and ETR changed in a similar way in both Longjiao 2 and Zhejiao 911. In addition, the ability of heat dissipation of Longjiao 2 was statistically higher than that found in Zhejiao 911 when treated at 5°C for one day. These data suggest that cultivar Longjiao 2 induces chilling tolerance by modulating critical pathways including photosynthesis and energy dissipation.

scholarly journals RETRACTED ARTICLE: Increased biomass productivity in green algae by tuning non-photochemical quenching

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Silvia Berteotti ◽  
Matteo Ballottari ◽  
Roberto Bassi
Keyword(s):  
Heat Dissipation ◽  
Biomass Productivity ◽  
Growth Conditions ◽  
Complex Stress ◽  
Biofuel Production ◽  
Photochemical Quenching ◽  
Protein Accumulation ◽  
Potential Productivity ◽  
Wide Range ◽  
Non Photochemical Quenching

Abstract Photosynthetic microalgae have a high potential for the production of biofuels and highly valued metabolites. However, their current industrial exploitation is limited by a productivity in photobioreactors that is low compared to potential productivity. The high cell density and pigment content of the surface layers of photosynthetic microalgae result in absorption of excess photons and energy dissipation through non-photochemical quenching (NPQ). NPQ prevents photoinhibition, but its activation reduces the efficiency of photosynthetic energy conversion. In Chlamydomonas reinhardtii, NPQ is catalyzed by protein subunits encoded by three lhcsr (light harvesting complex stress related) genes. Here, we show that heat dissipation and biomass productivity depends on LHCSR protein accumulation. Indeed, algal strains lacking two lhcsr genes can grow in a wide range of light growth conditions without suffering from photoinhibition and are more productive than wild-type. Thus, the down-regulation of NPQ appears to be a suitable strategy for improving light use efficiency for biomass and biofuel production in microalgae.

scholarly journals Photoprotection by carotenoids of Plantago media photosynthetic apparatus in natural conditions.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Tamara Golovko ◽  
Olga Dymova ◽  
Ilya Zakhozhiy ◽  
Igor Dalke ◽  
Galina Tabalenkova
Keyword(s):  
Heat Dissipation ◽  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Total Pool ◽  
Plantago Media ◽  
Non Photochemical Quenching ◽  
Sun Leaves ◽  
Daily Changes ◽  
Shade Plants

The study of daily changes in photosynthetic rate, of energy used in photochemical and non-photochemical processes, and of carotenoid composition aimed at evaluating the role of xanthophyll cycle (XC) in protection of hoary plantain plants (Plantago media) in nature. The leaves of sun plants differed from shade plants in terms of CO(2) exchange rate and photosynthetic pigments content. The total pool XC pigments and the conversion state increased from morning to midday in sun plants. An increase in zeaxanthin content occurred concomitantly with the violaxanthin decrease. About 80% violaxanthin was involved in conversion. The maximum of zeaxanthin in XC pigments pool was 60%. The conversion state of XC was twice as lower in shade plants than that in sun plants. The photosynthesis of sun leaves was depressed strongly at midday, but changes of maximum quantum yield of PS2 (F(v)/F(m)) were not apparent at that time. The coefficient qN (non-photochemical quenching) in the sun leaves changed strongly, from 0.3 to 0.9 as irradiance increased. The direct relation between heat dissipation and the conversion state of XC in plantain leaves was revealed. Thus, plantain leaves were found to be resistant to excess solar radiation due to activation of qN mechanisms associated with the XC de-epoxidation.

scholarly journals Combined chlorophyll fluorescence techniques to study environmental impact on the mountain moss Polytrichum commune

2021 ◽  
Vol 11 (1) ◽  
pp. 161-173
Author(s):  
Gabriella Nora Maria Giudici
Keyword(s):  
Chlorophyll Fluorescence ◽  
Conformational Changes ◽  
Heat Dissipation ◽  
Fluorescence Induction ◽  
High Light ◽  
Chlorophyll Fluorescence Induction ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Polytrichum Commune ◽  
Non Photochemical Quenching

Two chlorophyll fluorescence (ChlF) methods were used to study the effects of high light (photoinhibition) and dehydration, common stressors of the alpine environment, on primary photosynthetic processes in the moss Polytrichum commune from the Czech Republic, the Jeseníky Mountains. Photoinhibition (PI) was studied in fully hydrated thalli of P. commune and during the period of spontaneous desiccation. Time courses of Kautsky kinetics (KK) of ChlF and derived parameters: maximum quantum yield (FV/FM), effective quantum yeld (ΦPSII), and non-photochemical quenching parameters, were measured before and after the samples were treated with high light (1500 µmol m-2 s-1 PAR) for 60 min. Dehydration effects were tested in two sets of experiments with a Pulse-Amplitude-Modulation fluorometry (PAM) and Fast Chlorophyll Fluorescence induction curve (OJIP) techniques. In PAM tests, the desiccating samples were exposed to saturating light pulses every 10 min. in order to obtain ΦPSII and non-photochemical quenching (NPQ). In the second dehydration experiment, OJIP transients of ChlF were repeatedly recorded, OJIP-derived ChlF parameters were plotted against relative water content (RWC) monitored during desiccation. Combined ChF techniques provided insights into the mechanisms activated during P. commune desiccation, such as dissipation of excess absorbed energy through heat dissipation, and conformational changes or destructions of the light harvesting complexes. Combination of stressors resulted in amplified interference with the photosynthetic machinery, even when the added stressor (dehydration) was applied in low dose.

scholarly journals Genome-Wide Characterization of B-Box Gene Family and Its Roles in Responses to Light Quality and Cold Stress in Tomato

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Bu ◽  
Xiujie Wang ◽  
Jiarong Yan ◽  
Ying Zhang ◽  
Shunyuan Zhou ◽  
...  
Keyword(s):  
Cold Stress ◽  
Cold Tolerance ◽  
Genome Mapping ◽  
Electron Flow ◽  
Regulatory Elements ◽  
Photochemical Quenching ◽  
Protein Motif ◽  
Tomato Plants ◽  
High Conservation ◽  
Non Photochemical Quenching

Perceiving incoming environmental information is critical for optimizing plant growth and development. Multiple B-box proteins (BBXs) play essential roles in light-dependent developmental processes in plants. However, whether BBXs function as a signal integrator between light and temperature in tomato plants remains elusive. In this study, 31 SlBBX genes were identified from the newly released tomato (Solanum lycopersicum) genome sequences and were clustered into five subgroups. Gene structure and protein motif analyses showed relatively high conservation of closely clustered SlBBX genes within each subgroup; however, genome mapping analysis indicated the uneven distribution of the SlBBX genes on tomato chromosomes. Promoter cis-regulatory elements prediction and gene expression indicated that SlBBX genes were highly responsive to light, hormones, and stress conditions. Reverse genetic approaches revealed that disruption of SlBBX7, SlBBX9, and SlBBX20 largely suppressed the cold tolerance of tomato plants. Furthermore, the impairment of SlBBX7, SlBBX9, and SlBBX20 suppressed the photosynthetic response immediately after cold stress. Due to the impairment of non-photochemical quenching (NPQ), the excess photon energy and electron flow excited by low temperature were not consumed in SlBBX7-, SlBBX9-, and SlBBX20- silenced plants, leading to the over reduction of electron carriers and damage of the photosystem. Our study emphasized the positive roles of light signaling transcription factors SlBBXs in cold tolerance in tomato plants, which may improve the current understanding of how plants integrate light and temperature signals to adapt to adverse environments.

Characterisation of Three Components of Non-photochemical Fluorescence Quenching and Their Response to Photoinhibition

1988 ◽  
Vol 15 (2) ◽  
pp. 163 ◽  
Author(s):  
B Demmig ◽  
K Winter
Keyword(s):  
Fluorescence Quenching ◽  
Heat Dissipation ◽  
Photosynthetic Electron Transport ◽  
Co2 Assimilation ◽  
Nerium Oleander ◽  
Photochemical Quenching ◽  
Ps Ii ◽  
Fluorescence Characteristics ◽  
Non Photochemical Quenching ◽  
Three Components

Three components of non-photochemical fluorescence quenching were distinguished according to their response to irradiance and to their relaxation kinetics upon darkening. Two components of quenching were restricted to excessive irradiance and were interpreted to reflect radiationless dissipation. One relaxed rapidly upon darkening, and increased sharply when irradiance became excessive, i.e. as soon as net CO2 assimilation rate was no longer linearly related to irradiance, and attained a maximum value with only small further increases in irradiance. The second component relaxed slowly, increased mark- edly when the rapidly relaxing component had reached its maximum, and continued to increase linearly with increasing irradiance. The third component was already present at low irradiances, relaxed very slowly, and may be related to an altered distribution of excitation energy between PS II and PS I. Following exposure to weak illumination under conditions preventing photosynthetic electron transport (20 mbar O2, zero CO2), the reduction state of Q was initially high and decreased as non- photochemical fluorescence quenching indicative of radiationless dissipation developed. Subsequent to photoinhibitory treatments in high light and 20 mbar O2, zero CO2, an increased reduction state of Q as well as increased non-photochemical quenching of the two types indicative of increased heat dissipation was observed. In sunflower a lasting increase in the reduction state of Q was observed and fluorescence characteristics reflected photoinhibitory damage. In Nerium oleander, increased radiationless dissipation of the slowly relaxing type was the predominant response and the reduction state of Q was increased only transiently.

scholarly journals Linking remote sensing parameters to CO2 assimilation rates at a leaf scale

2021 ◽  
Author(s):  
Kouki Hikosaka ◽  
Katsuto Tsujimoto
Keyword(s):  
Remote Sensing ◽  
Chlorophyll Fluorescence ◽  
Heat Dissipation ◽  
Spatial Scales ◽  
Photochemical Efficiency ◽  
Co2 Assimilation ◽  
Photochemical Quenching ◽  
Future Prediction ◽  
Environmental Responses ◽  
Non Photochemical Quenching

AbstractSolar-induced chlorophyll fluorescence (SIF) and photochemical reflectance index (PRI) are expected to be useful for remote sensing of photosynthetic activity at various spatial scales. This review discusses how chlorophyll fluorescence and PRI are related to the CO2 assimilation rate at a leaf scale. Light energy absorbed by photosystem II chlorophylls is allocated to photochemistry, fluorescence, and heat dissipation evaluated as non-photochemical quenching (NPQ). PRI is correlated with NPQ because it reflects the composition of xanthophylls, which are involved in heat dissipation. Assuming that NPQ is uniquely related to the photochemical efficiency (quantum yield of photochemistry), photochemical efficiencies can be assessed from either chlorophyll fluorescence or PRI. However, this assumption may not be held under some conditions such as low temperatures and photoinhibitory environments. Even in such cases, photosynthesis may be estimated more accurately if both chlorophyll fluorescence and PRI are determined simultaneously. To convert from photochemical efficiency to CO2 assimilation, environmental responses in stomatal conductance also need to be considered. Models linking chlorophyll fluorescence and PRI with CO2 assimilation rates will contribute to understanding and future prediction of the global carbon cycle.

Light Absorption and Partitioning in Response to Nitrogen in Apple Leaves

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541a-541
Author(s):  
Lailiang Cheng ◽  
Leslie H. Fuchigami ◽  
Patrick J. Breen
Keyword(s):  
High Light ◽  
Thermal Dissipation ◽  
Photochemical Quenching ◽  
Light Conditions ◽  
Psii Efficiency ◽  
Fluorescence Measurements ◽  
Free Radical Formation ◽  
Highly Correlated ◽  
Non Photochemical Quenching ◽  
Leaf N

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.

scholarly journals Gradual Response of Cyanobacterial Thylakoids to Acute High-Light Stress—Importance of Carotenoid Accumulation

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1916
Author(s):  
Myriam Canonico ◽  
Grzegorz Konert ◽  
Aurélie Crepin ◽  
Barbora Šedivá ◽  
Radek Kaňa
Keyword(s):  
Single Cell ◽  
Thylakoid Membrane ◽  
Intermediate Phase ◽  
Light Stress ◽  
Fast Response ◽  
High Light ◽  
Photochemical Quenching ◽  
Second Phase ◽  
Ros Scavenging ◽  
Non Photochemical Quenching

Light plays an essential role in photosynthesis; however, its excess can cause damage to cellular components. Photosynthetic organisms thus developed a set of photoprotective mechanisms (e.g., non-photochemical quenching, photoinhibition) that can be studied by a classic biochemical and biophysical methods in cell suspension. Here, we combined these bulk methods with single-cell identification of microdomains in thylakoid membrane during high-light (HL) stress. We used Synechocystis sp. PCC 6803 cells with YFP tagged photosystem I. The single-cell data pointed to a three-phase response of cells to acute HL stress. We defined: (1) fast response phase (0–30 min), (2) intermediate phase (30–120 min), and (3) slow acclimation phase (120–360 min). During the first phase, cyanobacterial cells activated photoprotective mechanisms such as photoinhibition and non-photochemical quenching. Later on (during the second phase), we temporarily observed functional decoupling of phycobilisomes and sustained monomerization of photosystem II dimer. Simultaneously, cells also initiated accumulation of carotenoids, especially ɣ–carotene, the main precursor of all carotenoids. In the last phase, in addition to ɣ-carotene, we also observed accumulation of myxoxanthophyll and more even spatial distribution of photosystems and phycobilisomes between microdomains. We suggest that the overall carotenoid increase during HL stress could be involved either in the direct photoprotection (e.g., in ROS scavenging) and/or could play an additional role in maintaining optimal distribution of photosystems in thylakoid membrane to attain efficient photoprotection.

scholarly journals The Role of Acidic Residues in the C Terminal Tail of the LHCSR3 Protein of Chlamydomonas reinhardtii in Non-Photochemical Quenching

2021 ◽  
pp. 6895-6900
Author(s):  
Franco V. A. Camargo ◽  
Federico Perozeni ◽  
Gabriel de la Cruz Valbuena ◽  
Luca Zuliani ◽  
Samim Sardar ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Photochemical Quenching ◽  
Acidic Residues ◽  
Non Photochemical Quenching

scholarly journals Effects of iron limitation on carbon balance and photophysiology of the Antarctic diatom Chaetoceros cf. simplex

Polar Biology ◽  
2021 ◽  
Author(s):  
Deborah Bozzato ◽  
Torsten Jakob ◽  
Christian Wilhelm ◽  
Scarlett Trimborn
Keyword(s):  
Oxygen Evolution ◽  
Photochemical Quenching ◽  
Gross Photosynthesis ◽  
Manganese Zinc ◽  
C Cycle ◽  
Uptake Rates ◽  
Carbon Pump ◽  
Non Photochemical Quenching ◽  
The Antarctic ◽  
Biological Carbon Pump

AbstractIn the Southern Ocean (SO), iron (Fe) limitation strongly inhibits phytoplankton growth and generally decreases their primary productivity. Diatoms are a key component in the carbon (C) cycle, by taking up large amounts of anthropogenic CO2 through the biological carbon pump. In this study, we investigated the effects of Fe availability (no Fe and 4 nM FeCl3 addition) on the physiology of Chaetoceros cf. simplex, an ecologically relevant SO diatom. Our results are the first combining oxygen evolution and uptake rates with particulate organic carbon (POC) build up, pigments, photophysiological parameters and intracellular trace metal (TM) quotas in an Fe-deficient Antarctic diatom. Decreases in both oxygen evolution (through photosynthesis, P) and uptake (respiration, R) coincided with a lowered growth rate of Fe-deficient cells. In addition, cells displayed reduced electron transport rates (ETR) and chlorophyll a (Chla) content, resulting in reduced cellular POC formation. Interestingly, no differences were observed in non-photochemical quenching (NPQ) or in the ratio of gross photosynthesis to respiration (GP:R). Furthermore, TM quotas were measured, which represent an important and rarely quantified parameter in previous studies. Cellular quotas of manganese, zinc, cobalt and copper remained unchanged while Fe quotas of Fe-deficient cells were reduced by 60% compared with High Fe cells. Based on our data, Fe-deficient Chaetoceros cf. simplex cells were able to efficiently acclimate to low Fe conditions, reducing their intracellular Fe concentrations, the number of functional reaction centers of photosystem II (RCII) and photosynthetic rates, thus avoiding light absorption rather than dissipating the energy through NPQ. Our results demonstrate how Chaetoceros cf. simplex can adapt their physiology to lowered assimilatory metabolism by decreasing respiratory losses.

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