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252. Heliotropic leaf movement of Sophora alopecuroides L: an efficient strategy to optimise photochemical performance

Creator:
Zhu, C. G., Chen, Y. N., Li, W. H., Chen, X. L., and He, G. Z.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, Vnitřní Mongolsko (Čína), Inner Mongolia (China), jerlín, Ejina basin, electron transport rate, energy dissipation, leaf tilt angle, nonphotochemical quenching, petiole angle, quantum yield, trichome, Sophora alopecuroides L., 2, and 581
Language:
Multiple languages
Description:
We studied the survival adaptation strategy of Sophora alopecuroides L. to habitat conditions in an arid desert riparian ecosystem. We examined the responses of heliotropic leaf movement to light conditions and their effects on plant photochemical performance. S. alopecuroides leaves did not show any observable nyctinastic movement but they presented sensitive diaheliotropic and paraheliotropic leaf movement in the forenoon and at midday. Solar radiation was a major factor inducing leaf movement, in addition, air temperature and vapour pressure deficit could also influence the heliotropic leaf movement in the afternoon. Both diaheliotropic leaf movement in the forenoon and paraheliotropic leaf movement at midday could help maintain higher photochemical efficiency and capability of light utilisation than fixed leaves. Paraheliotropic leaf movement at midday helped plants maintain a potentially higher photosynthetic capability and relieve a risk of photoinhibition. Our findings indicated the effective adaptation strategy of S. alopecuroides to high light, high temperature, and dry conditions in arid regions. This strategy can optimise the leaf energy balance and photochemical performance and ensure photosystem II function., C. G. Zhu, Y. N. Chen, W. H. Li, X. L. Chen, G. Z. He., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

254. How can calibrated research-based models be improved for use as a tool in identifying genes controlling crop tolerance to environmental stresses in the era of genomics-from an experimentalist's perspective

Creator:
El-Sharkawy, M. A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
acclimation, adaptation, cassava, climate, CO2, evapotranspiration, genomics, leaves, photosynthesis, productivity, respiration, soil, water, and yield
Language:
Multiple languages
Description:
Almost four decades have passed since the new field of ecosystem simulation sprang into full force as an added tool for a sound research in an ever-advancing scientific front. The enormous advances and new discoveries that recently took place in the field of molecular biology and basic genetics added more effective tools, have strengthened and increased the efficiency of science outputs in various areas, particularly in basic biological sciences. Now, we are entering into a more promising stage in science, i.e. 'post-genomics', where both simulation modelling and molecular biology tools are integral parts of experimental research in agricultural sciences. I briefly review the history of simulation of crop/environment systems in the light of advances in molecular biology, and most importantly the essential role of experimental research in developing and constructing more meaningful and effective models and technologies. Such anticipated technologies are expected to lead into better management of natural resources in relation to crop communities in particular and plant ecosystems in general, that might enhance productivity faster. Emphasis is placed on developing new technologies to improve agricultural productivity under stressful environments and to ensure sustainable economic development. The latter is essential since available natural resources, particularly land and water, are increasingly limiting.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

255. Hydrogen peroxide in regulation of plant metabolism: Signalling and its effect under abiotic stress

Creator:
Khan, T. A., Yusuf, M., and Fariduddin, Q.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
antioxidanty, nízké teploty, fotosyntéza, antioxidants, low temperatures, photosynthesis, hydrogen peroxide, reactive oxygen species, signalling, 2, and 581
Language:
Multiple languages
Description:
In plants, hydrogen peroxide (H2O2) acts as a signalling molecule that facilitates various biochemical and physiological processes. H2O2 is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H2O2 also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants. Several signalling pathways involved in H2O2-mediated stress and defense responses have been extensively studied and there is ample scope of additional research that could further clarify the mechanism and modulating factors which regulate these pathways. An attempt has been made to dissect the role of H2O2 under low temperature stress and how it affects plant growth and development, photosynthetic capacity, regulation of antioxidant system, and signalling., T. A. Khan, M. Yusuf, Q. Fariduddin., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

256. Hypobaria and hypoxia affects phytochemical production, gas exchange, and growth of lettuce

Creator:
He, C., Jacobo-Velázquez, D. A., Cisneros-Zevallos, L., and Davies, F. T.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, bioprotectants, carbon assimilation, chlorophyll content, dark respiration rate, Lactuca sativa, low pressure, oxygen radical absorbance capacity, phytochemicals, 2, and 581
Language:
Multiple languages
Description:
Hypobaria (low total atmospheric pressure) is essential in sustainable, energy-efficient plant production systems for long-term space exploration and human habitation on the Moon and Mars. There are also critical engineering, safety, and materials handling advantages of growing plants under hypobaria, including reduced atmospheric leakage from extraterrestrial base environments. The potential for producing crops under hypobaria and manipulating hypoxia (low oxygen stress) to increase health-promoting bioactive compounds is not well characterized. Here we showed that hypobaric-grown lettuce plants (25 kPa ≈ 25% of normal pressure) exposed to hypoxia (6 kPa pO2 ≈ 29% of normal pO2) during the final 3 d of the production cycle had enhanced antioxidant activity, increased synthesis of anthocyananins, phenolics, and carotenoids without reduction of photosynthesis or plant biomass. Net photosynthetic rate (PN) was not affected by total pressure. However, 10 d of hypoxia reduced PN, dark respiration rate (RD), PN/RD ratio, and plant biomass. Growing plants under hypobaria and manipulating hypoxia during crop production to enhance health-promoting bioactive compounds is important for the health and well-being of astronauts exposed to space radiation and other stresses during long-term habitation. and C. He ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

257. Identification of obligate C3 photosynthesis in Dendrobium

Creator:
Qiu, S., Sultana, S., Liu, Z. D., Yin, L. Y., and Wang, C. Y.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, vstavačovité, photosynthesis, orchids, C3/CAM intermediate plant, CO2 exchange, crassulacean acid metabolism, titratable acidity, δ13C value, Dendrobium, 2, and 581
Language:
Multiple languages
Description:
Dendrobium is one of the three largest genera in the Orchidaceae and is distributed throughout various habitats. We investigated photosynthesis in seven Dendrobium species and cultivars by comparing their leaf δ13C values, titratable acidity, and CO2 exchange in well-watered and drought-stressed conditions. In addition, the leaf thickness and mesophyll succulence index (Sm) were measured in well-watered conditions. Our results indicate that Dendrobium loddigesii is a typical obligate (or constitutive) CAM plant because the leaf δ13C values were -14.47 and -14.66‰ in both conditions, respectively. Others showed the leaf thickness of 0.31-0.89 mm and their δ13C values ranged from -25.68 to -28.37‰. These are not the CAM plants but they could not be classified as obligate C3 or C3/CAM intermediate plants. Dendrobium crepidatum and Dendrobium fimbriatum were further identified as the obligate C3 plants because the net CO2 uptake was positive during daytime and negative during nighttime in both conditions. In contrast, Dendrobium chrysotoxum, Dendrobium nobile, and D. nobile ‘V1’ and ‘V4’, showed no positive net CO2 uptake and low ΔH+ values during nighttime under well-watered conditions, indicating C3 photosynthesis. However, they showed the positive net CO2 uptake and large ΔH+ values during nighttime after drought-stress (21 or 28 days without H2O), indicating CAM photosynthesis. Therefore, these four species and cultivars were identified as C3/CAM intermediate (inducible or facultative) plants. In brief, obligate CAM, C3/CAM intermediate, and obligate C3 plant types all exist in the section of Dendrobium. To the best of our knowledge, this is the first report of the obligate C3 plants in Dendrobium, and these diverse photosynthetic pathways may explain their varied environmental adaptations., S. Qiu, S. Sultana, Z. D. Liu, L. Y. Yin, C. Y. Wang., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

258. Impact of arbuscular mycorrhizal fungi on the growth, water status, and photosynthesis of hybrid poplar under drought stress and recovery

Creator:
Liu, T., Sheng, M., Wang, C. Y., Chen, H., Li, Z., and Tang, M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, topol, photosynthesis, poplar, Shaanxi (Čína : provincie), Shaanxi (China : Province), drought tolerance, gas exchange, nonphotochemical quenching, photosynthetic capacity, relative water content, Rhizophagus irregularis, 2, and 581
Language:
Multiple languages
Description:
Poplars (Populus spp.) are widely used in the pulp and paper industry and as bioenergy resources. Poplars require a large amount of water for biomass accumulation and lack of water is a limiting factor for poplar growth. Arbuscular mycorrhizal (AM) fungi have been previously reported to afford some plant species with greater resistance to drought stress. However, the effects of AM fungi on hybrid poplar under drought stress and recovery have not been studied. The main aim of this study was to evaluate the effects of the AM fungus, Rhizophagus irregularis, on the growth, water status, chlorophyll (Chl) content and fluorescence, and photosynthesis of poplar seedlings. The experiment was divided into three stages. At each stage of the experiment, the seedlings were subjected to a different watering regime: well-watered (prior stress), drought, and then rewatering (recovery). Measurements were taken at the end of each stage of the experiment. The results showed that mycorrhizal plants had a higher net photosynthetic rate and Chl fluorescence compared with nonmycorrhizal plants, regardless of the stage. Mycorrhizal and nonmycorrhizal plants showed different responses to drought stress: mycorrhizal plants showed better water-use efficiency and water uptake under drought stress conditions. In general, the poplar seedlings that formed the AM symbiosis with R. irregularis showed enhanced growth and reduced loss of biomass during the drought stress compared with the nonmycorrhizal seedlings., T. Liu, M. Sheng, C. Y. Wang, H. Chen, Z. Li, M. Tang., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

259. Impact of elevated CO2 on growth, physiology, yield, and quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish

Creator:
Mamatha, H., Srinivasa Rao, N. K., Laxman, R. H., Shivashankara, K. S., Bhatt, R. M., and Pavithra, K. C.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, pigmenty, rajčata, photosynthesis, pigments, tomatoes, gas exchange, growth characteristics, leaf water status, yield characteristics, Lycopersicon esculentum Mill) cv. Arka Ashish, 2, and 581
Language:
Multiple languages
Description:
Tomato meets the dietary nutrient and antioxidant requirements of diverse populations. Being a C3 crop and an important vegetable, it is likely to be influenced by increased CO2 concentrations under climate change situation. This study was conducted to investigate the effects of elevated CO2 on overall physiology, water relations, growth, yield, and fruit quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish. Plants were grown at elevated CO2 [550 (EC550) and 700 (EC700) ppm of CO2] in open top chambers. Increased assimilation rate, decreased stomatal conductance and transpiration rate were observed at elevated CO2 (EC) concentrations. Reduced leaf osmotic potential and increased water potential were observed at EC compared with the control (380 ppm of CO2) in flowering and fruiting stages. Lower total chlorophyll content was recorded at EC700. Plant height was significantly higher at EC550 compared with EC700. Higher number of branches was observed at EC700 as compared with plants grown at EC550 and the control. Leaf area was lower at EC700 compared with EC550 but specific leaf mass was higher at EC700. Due to higher leaf dry mass and root dry mass, the plants grown at EC700 exhibited higher total dry mass compared to EC550 and the control. Increased number of flowers and fruits together with higher fruit set led to higher fruit yield at both EC concentrations. The highest yield increase was observed at EC700. The fruits showed a lower content of phenols, flavonoids, ferric reducing antioxidant potential, total soluble solids, and titratable acidity in plants grown at EC as compared with the control. The ascorbic acid content was high at both EC700 and EC550. Carotenoids and lycopene content was low at EC700 compared to higher content observed at EC550 and the control., H. Mamatha, N. K. Srinivasa Rao, R. H. Laxman, K. S. Shivashankara, R. M. Bhatt, K. C. Pavithra., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

260. Impact of light-emitting diode irradiation on photosynthesis, phytochemical composition and mineral element content of lettuce cv. Grizzly

Creator:
Amoozgar, A., Mohammadi, A., and Sabzalian, M. R.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
karotenoidy, fotosyntéza, carotenoids, photosynthesis, LED technologie, hlávkový salát, obsah minerálů, fytochemikálie, LED technology, lettuce, mineral content, phytochemicals, 2, and 581
Language:
Multiple languages
Description:
Light-emitting diodes (LEDs) are a promising technology with a potential to improve the irradiance efficiency, light quality, and the light spectrum for increasing plant yield and quality. In this experiment, we investigated the impacts of various LED light qualities, including 100% red, 100% blue, 70% red + 30% blue, and 100% white, on the growth and photosynthesis, phytochemical contents, and mineral element concentrations in lettuce (Lactuca sativa L. cv. 'Grizzly') in comparison to normal greenhouse conditions. Photon flux of 300 µmol m-2 s-1 was provided for 14 h by 120 LEDs set on a 60 cm × 60 cm sheet of aluminum platform in the growth chambers, where plants were grown for 60 d. Fresh mass per plant was significantly higher when grown under 100% blue and 70% red + 30% blue LEDs compared to the other environments including greenhouse conditions. Phytochemical concentrations and a nutritive value of lettuce were also significantly affected by the light treatments. Chlorophyll and carotenoid concentrations increased in the plants grown under 70% red + 30% blue LEDs compared to those grown in the greenhouse. Vitamin C content was 2.25-fold higher in the plants grown under 100% blue LEDs compared to those grown in the greenhouse. Higher photosynthesis and maximal quantum yield of PSII photochemistry were also observed in the plants treated with LED lights. The application of LED light led to the elevated concentrations of macro-and micronutrients in lettuce possibly because of the direct effect of LED light and lower stress conditions in the growth chambers compared to the greenhouse. Although the mechanism of the changes in lettuce grown under LED is not well understood, the results of this study demonstrated that LED light could be used to enhance the growth and nutritional value of lettuce in indoor plant production facilities., A. Amoozgar, A. Mohammadi, M. R. Sabzalian., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public