Bioenergy (Biology)

This book empowers college students and young professionals to develop a critical capacity for climate action in the energy transformation necessary to address unprecedented climate crises. It illuminates the monumental challenges and pioneering solutions in accelerating renewable energy technologies, including solar energy, wind power, bioenergy, hydropower, and geothermal energy, as well as energy storage, along with their practical applications.
The book offers the most current insights into innovations in renewable energy and energy storage, which are pivotal in forging a reliable and sustainable future powered exclusively by renewables. Its chapters equip the younger generation with the knowledge and critical skills needed to become well-informed and discerning professionals, ready to meet the demands of future sustainable job markets. Readers are encouraged to actively engage in and contribute to the ongoing revolution in renewable energy and energy storage.

The effect of nitrate (NO;) on net sucrose synthesis and phosphoenolpyruvate activity was studied using two cultivars of the C,-plant Saccharinurn ojjkinurum, Jaronu 60-S (Ja 60-S) and Barbados 63-118 (B 63-118), high-and low-biomass producers respectively. Leaf segments were treated with a N-free solution, or 40-80 mM NO; in the light for 90 min. Rates of NO; uptake and assimilation were lower in Ja 60-5 than in B 63-118. in Ja 60-5 net sucrose synthesis was high and drastically reduced by NO;, while in B 63-118 it was lower and stimulated by NO; assimilation. In both cultivars, the main effect of NO; on phosphoenolpyruvate carboxyiase was to reduce its sensitivity to malate. It is suggested that the relative capacities for NO; assimilation and sucrose synthesis may be a factor involved in the control of sucrose synthesis by NO; and in the rapidity in which C metabolism is adjusted to N assimilation.

Highlights • Responsiveness of shaded leaves to light was evaluated in 13 sugarcane genotypes • CO2 uptake varied among genotypes under varying light conditions • IACCTC06-8126 and CTC4 have high responsiveness of shaded leaves to high light

Drying is one of the most important process in the cultivation of microalgae. Performance of drying depends on appropriate drying methods. This study aimed (1) to determine the effect of different drying methods on the Chlorella sp., Neochloris conjuncta, and Botryococcus braunii strains and (2) to identify the most suitable model for drying methods. Chlorella sp., Neochloris conjuncta and Botryococcus braunii cultures were grown in basal medium in raceways at the greenhouse condition in Isparta province. During experiment, air temperature and relative humidity, wind speed, solar irradiance, wet and dry mass and temperature of microalgae biomass were measured. Drying applications continued for approximately 3 days. Microalgae were dried at solar tunnel, outdoor, and greenhouse conditions. Furthermore, the effect of drying methods such as open sun, solar tunnel, and greenhouse drying on drying time, and drying ratio of microalgae have been investigated. The drying data were applied to ten different mathematical models, namely, Newton, Page, Henderson and Pabis, Logarithmic, Midilli and Kucuk, Wang and Singh, Two Term, Two Term Exponential, Weibull and Logistic Equation Models. The performance of these models were compared according to the coefficient of determination, standard error of estimate and residual sum of squares, between the observed and predicted moisture ratios. Results showed that the Weibull equation gave the best prediction to the drying kinetics evidenced by coefficient of determination ranging from 0.9959-0.9992 for all drying methods. In addition, solar tunnel drying method has been determined to be the most suitable one among tested methods for drying of microalgae.

Rising carbon dioxide (CO 2) concentrations, increasing ambient temperature and associated precipitation are major concerns for future weed management and crop production. Weeds with C 3 and C 4 photosynthetic pathways may exhibit differential responses to higher CO 2 levels and temperatures, which can affect the dynamics of crop-weed competition. Since photosynthetic biochemistry depends on climatic factors, the photosynthetic pathway of weeds C 3 and C 4 had shown varied responses to elevated concentrations of CO 2 and elevated temperature, the main source of carbon for plants, directly impacts gas exchange parameters at increased concentration of temperature and CO 2. This study evaluated the performance of Trianthema portulacastrum gas exchange parameter viz., photosynthetic rate, stomatal conductance, transpiration rate had positively interacted with increased temperature, excess moisture and also under drought condition. Hence, under this climatic condition, the Trianthema portulacastrum very well survives with adverse environmental conditions also by reduced transpiration rate and photosynthetic rate.

Anthracnose stalk rot (ASR) of maize results in millions of dollars in losses annually in the United States. ASR, together with anthracnose leaf blight and anthracnose top dieback, is caused by the fungus Colletotrichum graminicola. Current ASR management recommendations emphasize host resistance and reduction of plant stressors, e.g., drought, heat, low fertility, or soil acidity. Stress reduction may be more difficult to achieve in the future due to more high-intensity production protocols and climate change. Moreover, cultural and chemical management practices may conflict with other important goals including environmental sustainability and maximization of yield potential. Thus, future ASR management may rely more heavily on host resistance, for which there are relatively few highly effective sources. The last comprehensive review of C. graminicola and maize anthracnose was written over two decades ago. The genomic age has brought important new insights into mechanisms governing the host-pathogen interaction from the application of molecular and cytological technologies. This review provides a summary of our current model of maize anthracnose etiology, including how increased knowledge of molecular and cellular events could contribute to better ASR management. Improved understanding of C. graminicola taxonomy has confirmed that the fungus is specific to Zea mays, and that it

Since C 4 photosynthesis was first discovered >50 years ago, researchers have sought to understand how this complex trait evolved from the ancestral C 3 photosynthetic machinery on >60 occasions. Despite its repeated emergence across the plant kingdom, C 4 photosynthesis is notably rare in trees, with true C 4 trees only existing in Euphorbia. Here we consider aspects of the C 4 trait that could limit but not preclude the evolution of a C 4 tree, including reduced quantum yield, increased energetic demand, reduced adaptive plasticity, evolutionary constraints, and a new theory that the passive symplastic phloem loading mechanism observed in trees, combined with difficulties in maintaining sugar and water transport over a long pathlength, could make C 4 photosynthesis largely incompatible with the tree lifeform. We conclude that the transition to a tree habit within C 4 lineages as well as the emergence of C 4 photosynthesis within pre-existing trees would both face a series of challenges that together explain the global rarity of C 4 photosynthesis in trees. The C 4 trees in Euphorbia are therefore exceptional in how they have circumvented every potential barrier to the rare C 4 tree lifeform.

Microalgal biofuel has the potential to address two major global issues; 1) fulfill the rising energy demand of the world and 2) mitigate the increasing global warming by CO 2 sequestration. Botryococcus braunii is a unique alga producing high hydrocarbon contents which can be hydrocracked into high quality fuel. However, there is a lack of interest on the use of B. braunii for biofuel production due to its slow growth rate, an influencing parameter in determining the economics of conventional algal fuel production process. Non-destructive extraction (milking) of B. braunii hydrocarbons is a process which enables the alga to reproduce the hydrocarbons reducing the requirement of fast growth of this alga for biofuel production. This study targets to establish a techno-economics of B. braunii milking to analyze its potential for the renewable hydrocarbon production. The minimum sales price (MSP) to achieve a 10% rate of return was estimated to be US$3.20 L −1 of B. braunii hydrocarbons for the base case scenario. The extraction efficiency and the hydrocarbon contents were found to be the major economy drivers of the process as a result of the additional sensitivity analysis performed to identify the most economic influencing parameters. The MSP has the potential of significant reduction (down to US$1.45 L −1) if a B. braunii with higher hydrocarbon contents is identified as long as the selected strain is suitable for milking and the higher non-destructive extraction efficiency is achieved. A resource assessment comparison was also made to evaluate the significance of the repetitive extraction versus the single extraction. The milking has the clear advantage over the conventional single extraction regarding resource consumption and the cost of the process.

The kinetics of a stomatal response to sudden increases or decreases of CO 2 concentrations ([CO 2 ]) was studied in 13 plant species growing in the field. Plants were well supplied with water. In each plant, gas exchange measurements were made on a fully developed leaf that was first left to achieve steadystate stomatal conductance (g s) at 400 mol (CO 2) mol −1) and then exposed to a step change of [CO 2 ] (to 700 mol mol −1 in one experiment; and to 700 and back to 400 mol mol −1 in a second experiment). Porometric data were captured in intervals of 3 s until a new steady state was reached. A comparison of t 1/2 , the half-time needed to achieve new g s , indicates similar responses of stomata in grasses when compared to herbs. The stomata of C 4 plants responded in approximately 5 min, the highest closure rate was detected in Echinochloa crus-galli and Digitaria sanguinalis. Opening rates were similar to closing rates and the response as a whole was rather symmetric. In C 3 plants, the full response of stomata was much slower. Analysis revealed differences in absolute rates of g s change between C 3 and C 4 plants. These differences can be related to the specificities of the type of photosynthetic metabolism. C 4 photosynthesis enables plants to reduce g s , which can hasten further changes of diffusivity in response to the environmental signals. A possible coupling of C 4 metabolism to the regulation of guard cells also has to be taken into account when explaining the observed results.

The rate of net CO2 assimilation of mature wheat (Triticum aestivum L.) leaves in ambient air (21% 02. 340 microbars C02) declined with time of illumination at temperatures lower than 25°C, but not at higher temperatures, and the rate of decline increased when maintained in air with higher CO2 concentration (700425 microbars). In this latter case, the decline in the rate of net CO2 assimilation also occurred at high temperatures. Stomatal conductance also declined with time in some cases and stomata became more sensitive to C02, but this was not the primary cause of the decrease in CO2 assimilation because internal partial pressure of CO2 remained constant. Treatments which reduced the rate of translocation (e.g. lower temperatures, chilling the base of the leaf) produced a marked decline in CO2 assimilation of leaves in atmospheric and high CO2 concentrations. The decreased net CO2 assimilation was correlated with carbohydrate accumulation in each case, suggesting end product inhibition of photosynthesis. Analysis of CO2 assimilation in high carbohydrate leaves as a function of intercellular CO2 partial pressure showed reduction in the upper part of the curve. The initial slope of this curve, however, was not affected. Photosynthetic rates in the upper part of this curve generally recovered after a short period in darkness in which carbohydrates were removed from the leaf. The stimulation of net CO2 assimilation by 2% 02 (Warburg effect), and the apparent quantum yield, decreased after several hours of light.

The photosynthetic carbon assimilation pathways are not the same for all plants; they show great inventiveness through their adaptations to low CO2 concentrations, high O2, water stress, but also to different temperatures in the environments in which they live. From this point of view there are 3 photosynthetic cycles in plants: C3, C4 and CAM.

Background and Aims The C 4 perennial grass miscanthus has been found to be less sensitive to cold than most other C 4 species, but still emerges later in spring than C 3 species. Genotypic differences in miscanthus were investigated to identify genotypes with a high cold tolerance at low temperatures and quick recovery upon rising temperatures to enable them to exploit the early growing season in maritime cold climates. Suitable methods for field screening of cold tolerance in miscanthus were also identified. Methods Fourteen genotypes of M. sacchariflorus, M. sinensis, M. tinctorius and M. Â giganteus were selected and grown under warm (24 C) and cold (14 C) conditions in a controlled environment. Dark-adapted chlorophyll fluorescence, specific leaf area (SLA) and net photosynthetic rate at a photosynthetically active radiation (PAR) of 1000 lmol m-2 s-1 (A 1000) were measured. Photosynthetic light and CO 2 response curves were obtained from 11 of the genotypes, and shoot growth rate was measured under field conditions. Key Results A positive linear relationship was found between SLA and light-saturated photosynthesis (A sat) across genotypes, and also between shoot growth rate under cool field conditions and A 1000 at 14 C in a climate chamber. When lowering the temperature from 24 to 14 C, one M. sacchariflorus exhibited significantly higher A sat and maximum photosynthetic rate in the CO 2 response curve (V max) than other genotypes at 14 C, except M. Â giganteus 'Hornum'. Several genotypes returned to their pre-chilling A 1000 values when the temperature was increased to 24 C after 24 d growth at 14 C. Conclusions One M. sacchariflorus genotype had similar or higher photosynthetic capacity than M. Â giganteus, and may be used for cultivation together with M. Â giganteus or for breeding new interspecies hybrids with improved traits for temperate climates. Two easily measured variables, SLA and shoot growth rate, may be useful for genotype screening of productivity and cold tolerance.

Proliferation of plasmodesmata (PD) connections between bundle sheath (BS) and mesophyll (M) cells has been proposed as a key step in the evolution of two-cell C4 photosynthesis; However, a lack of quantitative data has hampered further exploration and validation of this hypothesis. In this study, we quantified leaf anatomical traits associated with metabolite transport in 18 species of BEP and PACMAD grasses encompassing four origins of C4 photosynthesis and all three C4 subtypes (NADP-ME, NAD-ME, and PCK). We demonstrate that C4 leaves have greater PD density between M and BS cells than C3 leaves. We show that this greater PD density is achieved by increasing either the pit field (cluster of PD) area or the number of PD per pit field area. NAD-ME species had greater pit field area per M-BS interface than NADP-ME or PCK species. In contrast, NADP-ME and PCK species had lower pit field area with increased number of PD per pit field area than NAD-ME species. Overall, PD density per M...

Bundle sheath chloroplast volume can 1 house sufficient Rubisco to avoid limiting C4 2 photosynthesis during chilling 3 4 Charles P. Pignon, Marjorie R. Lundgren, Colin P. Osborne, Stephen P. Long 5 1 University of Illinois, Carl R. Woese Institute for Genomic Biology and Departments of Crop 6 Sciences and of Plant Biology, 1206 W Gregory Drive, Urbana, IL 61801, USA. 7 2 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 8 15 Vassar Street, Cambridge, MA 02139, USA 9 3 Arnold Arboretum, Harvard University, 1300 Centre Street, Boston, MA 02131, USA. 10 4 Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. 11 5 Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, 12 Sheffield, S10 2TN, UK. 13

Increase in demand for our primary foodstuffs is outstripping increase in yields, an expanding gap that indicates large potential food shortages by mid-century. This comes at a time when yield improvements are slowing or stagnating as the approaches of the Green Revolution reach their biological limits. Photosynthesis, which has been improved little in crops and falls far short of its biological limit, emerges as the key remaining route to increase the genetic yield potential of our major crops. Thus, there is a timely need to accelerate our understanding of the photosynthetic process in crops to allow informed and guided improvements via in-silico-assisted genetic engineering. Potential and emerging approaches to improving crop photosynthetic efficiency are discussed, and the new tools needed to realize these changes are presented.

Photosynthetic manipulation provides new opportunities for enhancing crop yield. However, understanding and quantifying the importance of individual and multiple manipulations on the seasonal biomass growth and yield performance of target crops across variable production environments is limited. Using a state-of-the-art cross-scale model in the APSIM platform we predicted the impact of altering photosynthesis on the enzyme-limited (A c) and electron transport-limited (A j) rates, seasonal dynamics in canopy photosynthesis, biomass growth, and yield formation via large multiyear-by-location crop growth simulations. A broad list of promising strategies to improve photosynthesis for C 3 wheat and C 4 sorghum were simulated. In the top decile of seasonal outcomes, yield gains were predicted to be modest, ranging between 0% and 8%, depending on the manipulation and crop type. We report how photosynthetic enhancement can affect the timing and severity of water

Overwintering ability is an important selection criterion for Miscanthus breeding in temperate regions. Insufficient overwintering ability of the currently leading Miscanthus biomass cultivar, M. ×giganteus (M×g) '1993-1780', in regions where average annual minimum temperatures are-26.1 C (USDA hardiness zone 5) or lower poses a pressing need to develop new cultivars with superior cold tolerance. To facilitate breeding of Miscanthus, this study characterized phenotypic and genetic variation of overwintering ability in an M. sinensis germplasm panel consisting of 564 accessions, evaluated in field trials at three locations in North America and two in Asia. Genome-wide association (GWA) and genomic prediction analyses were performed. The Korea/N China M. sinensis genetic group is a valuable gene pool for cold tolerance. The Yangtze-Qinling, Southern Japan and Northern Japan genetic groups were also potential sources of cold-tolerance. A total of 73 marker-trait Accepted Article This article is protected by copyright. All rights reserved. associations were detected for overwintering ability. Estimated breeding value for overwintering ability based on these 73 markers could explain 55% of the variation for first winter overwintering ability among M. sinensis. Average genomic prediction ability for overwintering ability across 50 five-fold cross-validations was high (~0.73) after accounting for population structure. Common genomic regions for overwintering ability were detected by GWA analyses and a previous parallel QTL mapping study using three interconnected biparental F 1 populations. One QTL on Miscanthus LG 8 encompassed five GWA hits and a known cold-responsive gene, COR47. The other overwintering ability QTL on Miscanthus LG 11 contained two GWA hits and three known cold stress related genes, carboxylesterase 13 (CEX13), WRKY2 transcription factor, and cold shock domain (CSDP1). Miscanthus accessions collected from high latitude locations with cold winters had higher rates of overwintering, and more alleles for overwintering, than accessions collected from southern locations with mild winters.

Peru has the largest inventory of alpacas worldwide. Despite their importance as a source of net income for rural communities living at the Andean Plateau, data on energy requirements and methane (CH4) emissions for alpacas are particularly lacking. In 2019, the International Panel on Climate Change (IPCC; 2006, and Refinement 2019) outlined methods for estimating CH4 emissions from enteric fermentation and no methane (CH4) conversion factors were reported for camelids. IPCC has since updated its guidelines for estimating CH4 emissions from the enteric fermentation of livestock at a national scale. For greenhouse gas (GHG) inventory purposes, conversion factors were developed for ruminants but not for domestic South American camelids (SAC), with this category including alpacas. A mobile open-circuit respirometry system (head hood) for the rapid determination of CH4 and CO2 production, O2 consumption, and thereafter, heat production (HP) for camelids was built and validated. In addit...

Alpacas are a species of great importance in the Andean plateau, however, there  are not enough studies evaluating their energy metabolism and greenhouse gas emissions. Considering this, an indirect calorimetry system (head hood) was developed to measure these components. Overall, the proposed respiration system performed well in terms of both accuracy and reliability of measurements. Results from the validation study confirmed that alpacas have a lower metabolic basal rate and therefore lower energy requirements for maintenance than small ruminants.

Peru has the largest inventory of alpacas worldwide. Despite their importance as a source of net income for rural communities living at the Andean Plateau, data on energy requirements and methane (CH4) emissions for alpacas are particularly lacking. In 2019, the International Panel on Climate Change (IPCC; 2006, and Refinement 2019) outlined methods for estimating CH4 emissions from enteric fermentation and no methane (CH4) conversion factors were reported for camelids. IPCC has since updated its guidelines for estimating CH4 emissions from the enteric fermentation of livestock at a national scale. For greenhouse gas (GHG) inventory purposes, conversion factors were developed for ruminants but not for domestic South American camelids (SAC), with this category including alpacas. A mobile open-circuit respirometry system (head hood) for the rapid determination of CH4 and CO2 production, O2 consumption, and thereafter, heat production (HP) for camelids was built and validated. In addit...

Ulva, a common green seaweed, performs at the biochemical level as a typical C3 plant. Over 90% of label was found in glycerate 3-phosphate following a 3 second '4C pulse in the light, and the label was subsequently transferred to sugars. Also, the level of ribulose-1,5-bisphosphate carboxylase activity in crude extracts was about 10 times higher than that of phosphoenolpyruvate carboxylase. Concerning gas exchange, photosynthetic rates of Ulva showed no 02 sensitivity, indicating that photorespiratory CO2 losses are repressed as in C4 plants. This apparent anomaly could be explained by the efficient HCO3uptake system of Ulva which might concentrate CO2 to the chloroplasts, thus suppressing the oxygenase activity of ribulose-1,5-bisphosphate carboxylase.

Since C4 photosynthesis was first discovered >50 years ago, researchers have sought to understand how this complex trait evolved from the ancestral C3 photosynthetic machinery on >60 occasions. Despite its repeated emergence across the plant kingdom, C4 photosynthesis is notably rare in trees, with true C4 trees only existing in Euphorbia. Here we consider aspects of the C4 trait that could limit but not preclude the evolution of a C4 tree, including reduced quantum yield, increased energetic demand, reduced adaptive plasticity, evolutionary constraints, and a new theory that the passive symplastic phloem loading mechanism observed in trees, combined with difficulties in maintaining sugar and water transport over a long pathlength, could make C4 photosynthesis largely incompatible with the tree lifeform. We conclude that the transition to a tree habit within C4 lineages as well as the emergence of C4 photosynthesis within pre-existing trees would both face a series of challeng...

In C 4 photosynthesis, a part of CO 2 fixed by phosphoenolpyruvate carboxylase (PEPC) leaks from the bundlesheath cells. Because the CO 2 leak wastes ATP consumed in the C 4 cycle, the leak may decrease the efficiency of CO 2 assimilation. To examine this possibility, we studied the light dependence of CO 2 leakiness (r), estimated by the concurrent measurements of gas exchange and carbon isotope discrimination, initial activities of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and pyruvate, orthophosphate dikinase (PPDK), the phosphorylation state of PEPC and the CO 2 assimilation rate using leaves of Amaranthus cruentus (NAD-malic enzyme subtype, dicot) plants grown in high light (HL) and low light (LL). r was constant at photon flux densities (PFDs)`200 mmol m À2 s À1 and was around 0.3. At PFDs _150 mmol m À2 s À1 , r increased markedly as PFD decreased. At 40 mmol m À2 s À1 , r was 0.76 in HL and 0.55 in LL leaves, indicating that the efficiency of CO 2 assimilation at low PFD was greater in LL leaves. The activities of Rubisco and PPDK, and the phosphorylated state of PEPC all decreased as PFD decreased. Theoretical calculations with a mathematical model clearly showed that the increase in r with decreasing PFD contributed to the decrease in the CO 2 assimilation rate. It was also shown that the 'conventional' quantum yield of photosynthesis obtained by fitting the straight line to the light response curve of the CO 2 assimilation rate at the low PFD region is seriously overestimated. Ecological implications of the increase in r in LL are discussed.

The major energy currency molecule of the cell, ATP, and its relationship with melanin in the context of creationism are analyzed. These complex molecules are critical for all life from the simplest to the most complex. They are two of millions of enormously intricate nanomachines that need to have been designed in order for life to exist on earth. ATP is an excellent example of irreducible complexity because it is necessary in its entity in order for even the simplest form of life to survive. Without ATP, life as we understand it could not exist. ¿ How did life exist before ATP?

In C 4 photosynthesis, a part of CO 2 fixed by phosphoenolpyruvate carboxylase (PEPC) leaks from the bundlesheath cells. Because the CO 2 leak wastes ATP consumed in the C 4 cycle, the leak may decrease the efficiency of CO 2 assimilation. To examine this possibility, we studied the light dependence of CO 2 leakiness (r), estimated by the concurrent measurements of gas exchange and carbon isotope discrimination, initial activities of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and pyruvate, orthophosphate dikinase (PPDK), the phosphorylation state of PEPC and the CO 2 assimilation rate using leaves of Amaranthus cruentus (NAD-malic enzyme subtype, dicot) plants grown in high light (HL) and low light (LL). r was constant at photon flux densities (PFDs)`200 mmol m À2 s À1 and was around 0.3. At PFDs _150 mmol m À2 s À1 , r increased markedly as PFD decreased. At 40 mmol m À2 s À1 , r was 0.76 in HL and 0.55 in LL leaves, indicating that the efficiency of CO 2 assimilation at low PFD was greater in LL leaves. The activities of Rubisco and PPDK, and the phosphorylated state of PEPC all decreased as PFD decreased. Theoretical calculations with a mathematical model clearly showed that the increase in r with decreasing PFD contributed to the decrease in the CO 2 assimilation rate. It was also shown that the 'conventional' quantum yield of photosynthesis obtained by fitting the straight line to the light response curve of the CO 2 assimilation rate at the low PFD region is seriously overestimated. Ecological implications of the increase in r in LL are discussed.

The wild progenitors of major C 4 crops grew as individuals subjected to little shading. Today they are grown in dense stands where most leaves are shaded. Do they maintain photosynthetic efficiency in these low light conditions produced by modern cultivation? The apparent maximum quantum yield of CO 2 assimilation () , CO max,app 2 Φ Φ a key determinant of light-limited photosynthesis, has not been systematically studied in field stands of C 4 crops. Φ Φ CO max,app 2 was derived from the initial slope of the response of leaf CO 2 uptake (A) to photon flux (Q). Leaf fractional light absorptance (α) was measured to determine the absolute maximum quantum yield of CO 2 assimilation on an absorbed light basis (Φ Φ CO max,abs 2). Light response curves were determined on sun and shade leaves of 49 field plants of Miscanthus × giganteus and Zea mays following canopy closure. Φ Φ CO max,app 2 and Φ Φ CO max,abs 2 declined significantly by 15-27% (P<0.05) with canopy depth. Experimentally, leaf age was shown unlikely to cause this loss. Modeling canopy CO 2 assimilation over diurnal courses suggested that the observed decline in Φ Φ CO max,app 2 with canopy depth costs 10% of potential carbon gain. Overcoming this limitation could substantially increase the productivity of major C 4 crops.

Increasing the yield potential of the major food grain crops has contributed very significantly to a rising food supply over the past 50 years, which has until recently more than kept pace with rising global demand. Whereas improved photosynthetic efficiency has played only a minor role in the remarkable increases in productivity achieved in the last half century, further increases in yield potential will rely in large part on improved photosynthesis. Here we examine inefficiencies in photosynthetic energy transduction in crops from light interception to carbohydrate synthesis, and how classical breeding, systems biology, and synthetic biology are providing new opportunities to develop more productive germplasm. Near-term opportunities include improving the display of leaves in crop canopies to avoid light saturation of individual leaves and further investigation of a photorespiratory bypass that has already improved the productivity of model species. Longer-term opportunities inclu...

Longitudinal variation in carbon isotope discrimination (Δ), photosynthetic gas exchange, phosphoenolpyruvate carboxylase (PEPC) and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activities, chlorophyll and N content were characterised in the uppermost fully expanded leaf of sugarcane (Saccharum spp. hybrid) plants. Δ values of lamina tissue and the water-soluble fraction increased from the base to near the tip of the leaf then remained essentially constant, or declined along the rest of the leaf. Both the CO2 assimilation rate (A) and stomatal conductance (g) also increased from the base to the tip. The relative increase in A was much greater than that of g, causing the ratio of intercellular to ambient partial pressure of CO2 (pi/pa) to decrease substantially from leaf base to tip. Activities of both PEPC and Rubisco increased from leaf base to tip. Based on current models of factors determining Δ in C4 plants, the increase in Δ from the base to tip of sugarcane leaves...

Within a waste management company new data is accumulating in the different data management systems, but comprehensive utilisation of available data is too often neglected. New software products and systems, like driving guidance systems, are collecting additional information daily about the service areas. Extensive use of the gathered data as well as the data available in public and private domains can provide essential information for the planning and decision making of regional waste collection. In this study we explored the possibilities of refining, modelling and utilising the data stored in the operational databases of the Finnish waste management company Jatekukko Ltd. The focus of this study was especially on modelling and predicting waste formation with MLP (multi-layer perceptron) and giving an insight into future possibilities of utilising the modelled data.

Background: To determine the level of plant stress of second-generation biofuel crop Miscanthus x giganteus ( Mxg ) grown in poor quality post-military soils using physiological parameters; to identify impact of plant growth regulators (PGRs) on the stress reduction and to select the fluorescence indicators most suitable for quantification of stress. Plant fitness was quantified with non-invasive measurement of leaf fluorescence using 16 different indexes. Simultaneously visible stress signs were observed on stems and leaves and differences were revealed by microscopy of leaf sections. Results: Leaf fluorescence analysis, visual observation and changes of leaf anatomy revealed significant stress in all tested subjects . Besides commonly used F v /F m and P.I. (performance index), the fluorescence parameter T fm (time to achieve maximum fluorescence) seems to be rather sensitive and applicable for revealing finer differences. However, none of investigated parameters proved significan...

The placebo response is now believed to be far more pervasive than formally thought. As many as two-thirds of those taking an inert substance react positively, at least temporarily. In addition to taking “sugar pills” the placebo effect works under certain circumstances with phoney surgeries, specifically on the knee. Therefore, the claim that using a device like the orgone energy accumulator has an energetic response requires controlled experiments.

The goal of this study was to investigate whether chilling tolerance of C 4 photosynthesis in Miscanthus can be transferred to sugarcane by hybridization. Net leaf CO 2 uptake (A sat) and the maximum operating efficiency of photosystem II (Ф PSII) were measured in warm conditions (25°C/20°C), and then during and following a chilling treatment of 10°C/5°C for 11 day in controlled environment chambers. Two of three hybrids (miscanes), 'US 84-1058' and 'US 87-1019', did not differ significantly from the chilling tolerant M. 9giganteus 'Illinois' (Mxg), for A sat , and Φ PSII measured during chilling. For Mxg grown at 10°C/5°C for 11 days, A sat was 4.4 lmol m À2 s À1 , while for miscane 'US 84-1058' and 'US 87-1019', A sat was 5.7 and 3.5 lmol m À2 s À1 , respectively. Miscanes 'US 84-1058' and 'US 87-1019' and Mxg had significantly higher rates of A sat during chilling than three tested sugarcanes. A third miscane showed lower rates than Mxg during chilling, but recovered to higher rates than sugarcane upon return to warm conditions. Chilling tolerance of 'US 84-1058' was further confirmed under autumn field conditions in southern Illinois. The selected chilling tolerant miscanes have particular value for biomass feedstock and biofuel production and at the same time they can be a starting point for extending sugarcane's range to colder climates.

To enhance algal lipid and astaxanthin synthesis, the astaxanthin-producing green alga Haematococcus pluvialis was mix-cultivated with the antibiotic-synthesizing fungus Simplicillium lanosoniveum DT06 under non-aseptic conditions (NM) in this study. Results showed that in contrast to aseptic pure culture (AH) and non-aseptic pure culture (NH) of H. pluvialis , the production of cell (biomass), lipids and astaxanthin increased 56% and 119%, 112.4% and 279%, 74% and 175%, reaching 2.45 g/l, 0.837 g/l and 88.84 mg/l respectively; the average growth rate and the average specific growth rate increased 60.8% and 133.1 %, 19% and 31.6%, reaching 194.2 mg l -1 d -1 and 0.25 d -1 respectively; and the average lipid synthesis rate and average specific lipid synthesis rate increased 112.5% and 278.66%, 36.15% and 97%, reaching 69.75 mg l -1 d -1 and 28.47 mg g -1 d -1 respectively; and also the content of C16-C18 fatty acids that are suitable for biofuels production increased to 83.19%. There...

Miscanthus ×giganteus (M×g) is an important bioenergy feedstock crop. However, biomass production of Miscanthus has been largely limited to one sterile triploid cultivar, M×g '1993-1780', which we demonstrate can have insufficient overwintering ability in temperate regions with cold winters. Key objectives for Miscanthus breeding include greater biomass yield and better adaptation to different production environments than M×g '1993-1780'. In this study, we evaluated 13 M×g genotypes, including '1993-1780', in replicated field trials conducted for three years at Urbana, IL, Dixon Springs, IL, and Jonesboro, AR. Entries were phenotyped for first-winter overwintering ability and plant hardiness (ratio of new tillers to old), yield in years 2 and 3, and first heading date, plant height, and culm number in years 1 and 2. We observed substantial variation for overwintering ability and biomass yield among the M×g genotypes tested, and identified ones with better overwintering ability and/or higher biomass yield than '1993-1780'. Most entries at Urbana were damaged during the first winter, whereas few or no entries were damaged at Dixon Springs or Jonesboro. However, M×g 'Nagara' was entirely undamaged during the first winter and produced high biomass yields at Urbana (19.7 Mg ha-1 in year 2 and 20.9 Mg ha-1 in year 3), whereas M×g '1993-1780' exhibited an overwintering loss of 29%, had severely damaged survivors (hardiness score of 25%), and reduced biomass yield (8.1 Mg ha-1 in year 2 and 16.2 Mg ha-1 in year 3), indicating that M×g 'Nagara' could be a better choice in hardiness zone 5 (average annual minimum air temperature of-23.3 to-28.9 °C) or lower. In Dixon Springs, where M×g '1993-1780' was undamaged by the first winter, it yielded highest among all the entries (21.6

Light, besides initiating primary photochemical processes, alters the redox state of soluble components in chloroplast. The present review attempts to cover the mechanism of reductive photoactivation of enzymes of photosynthetic carbon reduction cycle using key enzymes as examples. The reduced soluble components-ferredoxin, thioredoxin and NADPH, in turn, cause the reduction of disulphides to dithiols of chloroplastic enzymes. NADP-malate dehydrogenase is subject to activation by light through changes in NADPH/NADP. The key enzyme of C 4 photosynthesis-PEP carboxylase, though cytosolic, has been shown to be activated by disulphide/sulphhydryl interconversion by reductants generated in light through chloroplast electron transport flow. Pyruvate P i dikinase activity is controlled by the adenylate energy charge. It remains unclear how light controls the activation of cytosolic enzymes.

Grain chaff could provide 54.8 Mt of additional annual potential biomass in Europe. In the framework of the AGROinLOG H2020 Project, the chaff collection system developed by Thierart company was tested in Sweden to evaluate the amount of biomass collectible, the harvesting losses and performance, and the economic feasibility of the system. Such system allows to collect the chaff separately onto a trailer. The total residual biomass increased by 0.84 t ha-1 without negatively affecting the performance of the combine.

The major energy currency molecule of the cell, ATP, and its relationship with melanin in the context of creationism are analyzed. These complex molecules are critical for all life from the simplest to the most complex. They are two of millions of enormously intricate nanomachines that need to have been designed in order for life to exist on earth. ATP is an excellent example of irreducible complexity because it is necessary in its entity in order for even the simplest form of life to survive. Without ATP, life as we understand it could not exist. ¿ How did life exist before ATP?

One of the problems of sustainable agricultural land management (SALM) is the competition between food production and biomass production. For this reason, marginal lands with unfavorable agrotechnical conditions have been proposed for non-food crops in recent years. To this end, a better understanding of the impact of environmental factors on crop development and yield is needed. The objective of the study was to investigate the effects of soil water availability on selected morphological, physiological and growth characteristics of four C4 grass species (Miscanthus × giganteus, Miscanthus sacchariflorus, Miscanthus sinensis and Spartina pectinate) growing under different water and fertilizer conditions. A pot experiment was conducted under greenhouse conditions with four grass species, three different water rates (100, 85 and 70%) and three fertilizer rates (270, 180 and 90 kg NPK ha−1). The study showed that water stress, regardless of plant species, increased the chlorophyll cont...

Main conclusion The changes in the expression of key sugar metabolism enzymes (SPS and SUS), sucrose content and arrangement of chloroplast starch may play a significant role in the cold response in M. giganteus and maize plants. Abstract To understand the mechanism of the chilling-response of two closely-related C4 plants, we investigated the changes in the expression of sucrose phosphate synthase (SPS) and sucrose synthase (SUS) as well as changes in their potential products: sucrose, cellulose and starch in the leaves of Miscanthus × giganteus and Zea mays. Low temperature (12–14 °C) increased SPS content in Miscanthus (MG) and chilling-sensitive maize line (Zm-S), but not in chilling-tolerant one (Zm-T). In Zm-S line, chilling also caused the higher intensity of labelling of SPS in the cytoplasm of mesophyll cells, as demonstrated by electron microscopy. SUS labelling was also increased by cold stress only in MG plants what was observed in the secondary wall between mesophyll an...