Search

To reveal the causes of photosynthetic characteristics of Yulania denudata with variegated leaf, the green leaves, variegated leaves and yellow leaves of Y. denudata with variegated leaf were used as experimental materials. The anatomical structure and photosynthetic characteristics in three types of leaves were compared from the aspects of photosynthetic pigment content, leaf anatomical structure and light response curve. The results were as follows: (1) The yellow leaf spots of Y. denudata with variegated leaf were chlorophyll-type leaf spots formed by the decrease of chlorophyll content due to the abnormal structure of chloroplasts. (2) The structure of thylakoids in the yellow region of Y. denudata with variegated leaf was abnormal, and ATP synthesis was blocked, which hindered the progress of photosynthesis. (3) The anatomical structure showed that the palisade tissue of the green leaf was developed, the chloroplast integrity and pigment content were higher than those of the variegated leaf and the yellow leaf, and the net photosynthetic rate was higher. (4) There were significant differences in the maximum net photosynthetic rate and light saturation point between the green leaf and the variegated leaf, and the green leaf could withstand a wider range of bright light than the variegated leaf. This study further elucidates that the chloroplast structure of Y. denudata with variegated leaf affects its photosynthetic characteristics, and provides a reference for the breeding of excellent germplasm of Y. denudata with variegated leaf. [ABSTRACT FROM AUTHOR]

Malus baccata, a valuable germplasm resource in the genus Malus, is indigenous to China and widely distributed. However, little is known about the lineage composition and genetic basis of 'ZA', a mutant type of M. baccata. In this study, we compared the differences between 'ZA' and wild type from the perspective of morphology and ultrastructure and analyzed their chloroplast pigment content based on biochemical methods. Further, the complete mitogenome of M. baccata 'ZA' was assembled and obtained by next-generation sequencing. Subsequently, its molecular characteristics were analyzed using Geneious, MISA-web, and CodonW toolkits. Furthermore, by examining 106 Malus germplasms and 42 Rosaceae species, we deduced and elucidated the evolutionary position of M. baccata 'ZA', as well as interspecific variations among different individuals. In comparison, the total length of the 'ZA' mitogenome (GC content: 45.4%) is 374,023 bp, which is approximately 2.33 times larger than the size (160,202 bp) of the plastome (GC: 36.5%). The collinear analysis results revealed abundant repeats and genome rearrangements occurring between different Malus species. Additionally, we identified 14 plastid-driven fragment transfer events. A total of 54 genes have been annotated in the 'ZA' mitogenome, including 35 protein-coding genes, 16 tRNAs, and three rRNAs. By calculating nucleotide polymorphisms and selection pressure for 24 shared core mitochondrial CDSs from 42 Rosaceae species (including 'ZA'), we observed that the nad3 gene exhibited minimal variation, while nad4L appeared to be evolving rapidly. Population genetics analysis detected a total of 1578 high-quality variants (1424 SNPs, 60 insertions, and 94 deletions; variation rate: 1/237) among samples from 106 Malus individuals. Furthermore, by constructing phylogenetic trees based on both Malus and Rosaceae taxa datasets, it was preliminarily demonstrated that 'ZA' is closely related to M. baccata, M. sieversii, and other proximate species in terms of evolution. The sequencing data obtained in this study, along with our findings, contribute to expanding the mitogenomic resources available for Rosaceae research. They also hold reference significance for molecular identification studies as well as conservation and breeding efforts focused on excellent germplasms. [ABSTRACT FROM AUTHOR]

Salinity is one of the most severe environmental stresses that negatively affects field crops' development and biochemical properties on a widespread global scale. Consequently, aiming to reduce the negative impact of salinity on plants, the objective of the current work was to study the effect of foliar spraying with two doses of yeast extract (2 and 4 g/L) on improving the growth of Vicia faba plants under NaCl stress (100 mM). The recorded results indicated that 100 mM NaCl level significantly decreased all investigated growth metrics (shoot height, root length, number of leaves, leaf area, fresh and dry weights of shoot and roots). Likewise, concentration of chloroplast pigments and the contents of total soluble protein and sugars were reduced in salt stressed faba bean leaves. Nevertheless, data revealed that V. faba plants grown under NaCl stress and sprayed with yeast extract had better growth behavior than those unsprayed. It was found that yeast extract treatment had the ability to induce significant recovery for the reduction occurred in vegetative growth of V. faba plants which exposed to salinity stress by more enhancement of pigment, total soluble protein and sugars contents. Among the yeast extract doses, 2 g/L significantly improved plant growth, biochemical traits and exposed high Mg, K, P content and K/Na ratio in V. faba plants grown under saline stress. It was found that treating V. faba plants with yeast extract can significantly restore the loss of vegetative growth caused by salt stress. NaCl stress (100 mM) significantly decreased all investigated growth parameters and pigment fractions of Vicia faba plants. Yeast extract treatment recovering the reduction occurred in vegetative growth of V. faba plants which exposed to salinity stress. The physiological parameters and ions content of V. faba plants were enhanced as a result of yeast extract application at 2 g/L under 100mM NaCl stress. [ABSTRACT FROM AUTHOR]

Yellowing leaves are ideal materials for studying the metabolic pathways of photosynthetic pigment chloroplast development, and the mechanism of photosynthetic systems. Here, we obtained a triploid material HCC (2n = 3x = 26), which was derived from hybridization between the artificial tetraploid Cucumis × hytivus (2n = 4x = 38, HHCC) and the cultivated cucumber Cucumis sativus (2n = 2x = 14, CC), and this triploid HCC showed obvious leaf yellowing characteristics. Phenotypic observation results showed that chloroplast development was impaired, the chlorophyll content decreased, and photosynthesis decreased in yellowing HCC leaves. The transcriptome results indicated that HCC-GLK is significantly downregulated in HCC and participates in the regulation of leaf yellowing. GO enrichment analysis revealed that differential genes were enriched in the heme binding and tetrapyrrole binding pathways related to leaf color. KEGG enrichment analysis revealed that differential genes were predominantly enriched in photosynthesis-related pathways. The experimental results of VIGS and yeast hybridization showed that silencing the GLK gene can induce leaf yellowing in cucumber plants, and the GLK protein can affect plant chloroplast development by interacting with the CAB3C protein (light-harvesting chlorophyll a/b binding) in the plant chlorophyll synthesis pathway. The current findings have not only enhanced our understanding of the regulatory mechanism of the GLK transcription factor in cucumber but also introduced novel insights and directions for investigating the molecular mechanism underlying polyploid leaf yellowing. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The combined drought and heat (DH) stress have devastating effects on plant physiological and biochemical processes, leading to poor yield. The aims of this study were to identify the physio-biochemical mechanisms employed by edamame (Glycine max L. Merrill) for survival and to establish better performing cultivars under DH stress. The impact of DH stress on the photosynthesis efficiency and osmolytes production in three edamame cultivars (UVE14, UVE17 and AGS429) was investigated. Non-destructive measurements were performed to determine the photosynthesis attributes, while pigments, non-structural carbohydrates (starch, glucose, sucrose, trehalose) and proline were extracted and quantified spectrophotometrically. The results showed that chlorophyll a (Chl-a), Chl-b, total chlorophyll and carotenoids in AGS429 were not affected under DH stress, which corresponded to increased normalised difference vegetative index (NDVI). Positive correlations between the carotenoids and total chlorophyll contents suggest that in AGS429, prevention of chlorophyll degradation under DH stress could be attributed to the increased carotenoids because they have antioxidative function. Additionally, AGS429 and UVE14 had increased trehalose, suggesting high osmotic adjustment under DH stress. An increase in starch production maintained glucose balance in AGS429 and UVE14, demonstrating higher photosynthetic efficiency compared to UVE17. The DH stress reduced photochemical reactions and carbohydrate accumulation in UVE17. This study shows that AGS429 and UVE14 protected the photosystems and photosynthetic pigments during DH stress, which led to higher photosynthetic capacity and accumulation of carbohydrates. Thus, maintaining the photosynthesis efficiency and carbohydrate metabolism processes in the AGS429 and UVE14 were adaptation features under DH stress.

Saline-sodic stress can limit the absorption of available zinc in rice, subsequently impacting the normal photosynthesis and carbohydrate metabolism of rice plants. To investigate the impact of exogenous zinc application on photosynthesis and carbohydrate metabolism in rice grown in saline-sodic soil, this study simulated saline-sodic stress conditions using two rice varieties, 'Changbai 9' and 'Tonghe 899', as experimental materials. Rice seedlings at 4 weeks of age underwent various treatments including control (CT), 2 μmol·L−1 zinc treatment alone (Z), 50 mmol·L−1 saline-sodic treatment (S), and 50 mmol·L−1 saline-sodic treatment with 2 μmol·L−1 zinc (Z + S). We utilized JIP-test to analyze the variations in excitation fluorescence and MR820 signal in rice leaves resulting from zinc supplementation under saline-sodic stress, and examined the impact of zinc supplementation on carbohydrate metabolism in both rice leaves and roots under saline-sodic stress. Research shows that zinc increased the chloroplast pigment content, specific energy flow, quantum yield, and performance of active PSII reaction centers (PIABS), as well as the oxidation (VOX) and reduction rate (Vred) of PSI in rice leaves under saline-sodic stress. Additionally, it decreased the relative variable fluorescence (WK and VJ) and quantum energy dissipation yield (φDO) of the rice. Meanwhile, zinc application can reduce the content of soluble sugars and starch in rice leaves and increasing the starch content in the roots. Therefore, the addition of zinc promotes electron and energy transfer in the rice photosystem under saline-sodic stress. It enhances rice carbohydrate metabolism, improving the rice plants' ability to withstand saline-sodic stress and ultimately promoting rice growth and development. [ABSTRACT FROM AUTHOR]

Elicitation is a valuable tool to improve essential oil production. In order to evaluate the effects of methyl jasmonate (MJ) and salicylic acid (SA) as elicitors in the morphophysiological attributes and in the content and profile of essential oil (EO) of lemon balm (Lippia alba). In a greenhouse, L. alba plants were cultivated and subjected to foliar spraying with solutions of Methyl Jasmonate (0, 1, 2 and 4 mM) and Salicylic acid (0, 1, 2 and 4 mM). The results indicated that the concentrations used did not increase plant growth, however, it stimulated the increase in the number of inflorescences per plant. The EO contents were favored with the elicitation, with productivity varying between 0.57 and 0.89%, higher than the control treatment with distilled water (0.45%). Application of MJ and SA affected chloroplast pigments, gas exchange parameters and trichomes density. Chemical analysis of essential oils identified the presence of 78 compounds. The MJ induced the presence of 71 compounds, being 16 exclusive, while the plants treated with SA presented 35 compounds, having only as exclusive. The major compounds varied according to the treatments, however, the main substances were Geranial, Geraniol, β-caryophyllene, Caryophyllene oxide, Germacrene D, Myrcene and Eugenol. Therefore, the application of elicitors in L. alba plants, especially at concentrations of 2 mM of MJ and 4 mM of SA, has the potential to modulate physiological responses and stimulate secondary metabolism, as well as the production of certain molecules, such as monoterpenes, sesquiterpenes and phenylpropanoids. [ABSTRACT FROM AUTHOR]

This study pursued tests on 17 local and exotic soybean (Glycine max L. Merr.) cultivars with two different water regimes. In the optimal irrigated condition (control), the soybean plants gained five times irrigation in the scheme of 1:3:1 during the vegetation period, with the total volume of water used for that irrigation being 5000-5500 m3/ha. For the water deficit condition, irrigation was only three times on the scheme 1:1:1, using a total volume of water at 3000-3500 m3/ha. In the optimal irrigated condition, water provision was only once during the formation of soybean leaves, three times during the budding period, and once again at the beginning of the blooming period. In that condition, the provision of an artificially created water deficit condition and drought with one irrigation ensued at the beginning of the blossoming period. According to the results, chlorophyll "b" pigment was more sensitive to water deficit conditions than chlorophyll "a." The increase in chlorophyll "b" under drought conditions increased chlorophyll's protection function, the primary photosynthetic pigment, with its reception of photons from sunlight. Stress enzyme activity increased to different extents compared with optimal water supply conditions in the soybean cultivars under water deficit conditions. The number of chloroplast pigments in plant leaves and the activity of peroxidase, catalase, and superoxide dismutase enzymes in leaves strongly influenced local and exotic soybean genotypes during the blooming-harvest period under drought conditions. With water deficit conditions, the number of pods per plant and 1000-grain weight reduced from 8.6% to 63.7% and 1.7% to 12.8% in the local and 3.8% to 28.3% and 5.6% to 58.8% in exotic soybean cultivars compared with water optimal conditions. [ABSTRACT FROM AUTHOR]

The current study was designed to assess the comparative morphology of eight olive cultivars with different geographical origins and diverse genetic backgrounds, introduced to a new climatic zone. The morphological parameters of eight (five exotic and three domestic) olive cultivars (Bari Zaitoon-1, Bari Zaitoon-2, Favolosa (FS-17), Koroneiki, Balkasar, Ottobratica, Leccino, and Arbequina) were compared at the experimental area of the Department of Botany, The Islamia University of Bahawalpur, Pakistan (29°24′0″ North, 71°41′0″ East, 401–421 feet above sea level). Plant height, number of leaves/15 cm shoot, leaf size characteristics (leaf length, leaf width, leaf area, and length/width ratio), leaf shape characteristics (margin, leaf axil, base, and apex angles), leaf pigments (Chlorophyll a, Chlorophyll b, total chlorophyll contents, and carotenoids), phyllotaxy, and leaf color and venation were recorded. The highest plant height (28 cm) was obtained by Bari Zaitoon-2 followed by Bari Zaitoon-1 (24 cm), both of which are domestic cultivar of Pakistan, while the shortest height (5 cm) was obtained by Koroneiki. Leccino displayed the highest average number of leaves (17.8) on main shoot, followed by BARI-2 (16.4) and the lowest score was from Balkasar (10.4). Leaf area ranged from 5.66 cm2 (Bari Zaitoon-1) to 3.08 cm2 (Koroneiki). The longest leaf length (5.74 cm) was found in Bari Zaitoon-1 and the shortest (4.04 cm) in Koroneiki, while the broadest leaves were found in Leccino (1.54 cm) and the narrowest (1.12 cm) in Koroneiki. Bari Zaitoon-2 led in leaf length to width ratio (4.058) followed by Bari Zaitoon-1 (3.772) with small lanceolate leaves hardly reaching the value of 4, with the lowest value illustrated by Leccino. The total chloroplast pigments were highest in FS-17 followed by Bari Zaitoon-1 and Bari Zaitoon-2, while the lowest was in Arbequina. Chlorophyll a was highest in Bari Zaitoon-1 followed by FS-17 and Balkasar, with the lowest rate in Arbequina. Chlorophyll b content of FS-17 was the highest whereas the Chlorophyll b and total chlorophyll contents in Arbequina were the lowest of all the cultivars. The highest value of total carotenoids was found in Balkasar followed by FS-17 with the lowest value in Arbequina. The phyllotaxy was categorized into three types, i.e., alternate, opposite, and whorled. The combination of two or more types was usually observed on the same branch. The whorl of four leaves was also present in rare cases. Leaf venation was both pinnate and reticulate. The leaf base of most (four) of the olive cultivars, i.e., Arbequina, Balkasar, Leccino and FS-17, were cuneate having acute, rounded, apiculate, and cuspidate leaf tips, respectively. The findings revealed remarkable variations in olive morphology, especially in the leaves and a successful record of the preliminary data of olive cultivars from the study area was made. The present research demonstrated that local olive cultivars have unique characteristics that differentiate them from imported cultivars. Thus, local cultivars provide novel genetic resources that should be conserved. [ABSTRACT FROM AUTHOR]

Leaf optical properties can be used to identify environmental conditions, the effect of light intensities, plant hormone levels, pigment concentrations, and cellular structures. However, the reflectance factors can affect the accuracy of predictions for chlorophyll and carotenoid concentrations. In this study, we tested the hypothesis that technology using two hyperspectral sensors for both reflectance and absorbance data would result in more accurate predictions of absorbance spectra. Our findings indicated that the green/yellow regions (500–600 nm) had a greater impact on photosynthetic pigment predictions, while the blue (440–485 nm) and red (626–700 nm) regions had a minor impact. Strong correlations were found between absorbance (R2 = 0.87 and 0.91) and reflectance (R2 = 0.80 and 0.78) for chlorophyll and carotenoids, respectively. Carotenoids showed particularly high and significant correlation coefficients using the partial least squares regression (PLSR) method (R2C = 0.91, R2cv = 0.85, and R2P = 0.90) when associated with hyperspectral absorbance data. Our hypothesis was supported, and these results demonstrate the effectiveness of using two hyperspectral sensors for optical leaf profile analysis and predicting the concentration of photosynthetic pigments using multivariate statistical methods. This method for two sensors is more efficient and shows better results compared to traditional single sensor techniques for measuring chloroplast changes and pigment phenotyping in plants. [ABSTRACT FROM AUTHOR]

Trees of the sweet cherry cultivar 'Grace Star' (Prunus avium L.) were exposed to low temperatures without frost for two consecutive nights under natural conditions 36 d after flowering, to study the effects on the physiological properties and metabolic status of leaves. The response was studied by measuring chlorophyll fluorescence and gas exchange parameters and by analyzing chloroplast pigments (i) immediately after exposure, (ii) 24 h and (iii) 48 h later. The first exposure at 2.4 (±0.2) °C and a minimum of 0.8 °C elicited more changes than the second exposure at 4.9 (±0.3) °C and a minimum of 2.4 °C. After the first exposure, the maximum quantum yield of PS II (Fv/Fm), effective quantum efficiency of PS II, net photosynthesis (PN), stomatal conductance (gs), transpiration, and intercellular CO2 concentration were significantly lower, and after the second exposure, the content of chlorophyll b, total chlorophyll, β-carotene, and lutein were lower. The content of antheraxanthin and zeaxanthin was higher immediately after both exposures, and that of antheraxanthin was also higher 24 h later. Recovery took longer in trees that were exposed twice. Fv/Fm recovered within 48 h, but the de-epoxidation state of the xanthophyll cycle pool, PN, and gs did not reach the level of controls, indicating that the stress effect lasted several days which is probably sufficient to cause fruit drop and reduce yield. [ABSTRACT FROM AUTHOR]

Due to its nutritional value, wheatgrass (Triticum aestivum L.) is considered to be a functional food, becoming increasingly popular as a supplement to the people’s quotidian diet. The study aimed to determine the influence of the number of cuttings and cultivars on the total antioxidant activity (DPPH), the content of chloroplast pigments, vitamin C, phenols, and flavonoids in the wheatgrass juice. Two genotypes of wheatgrass, T. aestivum ssp. aestivum (variety Katarina) and T. aestivum ssp. sphaerococcum, respectively, were cut twice during the experiment. In both cuttings, the genotype significantly differed in the flavonoid level and antioxidant activity, while the number of cuttings influenced the content of phenols, vitamin C, and antioxidant activity in the wheatgrass juice. T. sphaerococcum had a higher concentration of flavonoids and a significantly lower antioxidant activity when compared to the Katarina wheat variety. On an average, the first cut implicated an increased content of phenols and vitamin C concerning both genotypes, followed by a higher antioxidant value. In the Katarina variety, a significantly higher phenol content and antioxidant activity was detected in the first cut. In the T. Sphaerococcum, a decrease in the total content of the examined antioxidants was apparent in the second cut.

The magnetic field can change the polarity characteristics and hydrogen-bond structure of water; therefore, magnetized water can affect plant growth and development. Magnetized water is hexagonal water created by passing water through a specific magnet that can activate and ionize water molecules to change its structure. This review highlights the use of magnetized water in the agricultural sector to enhance plant growth and food productivity. We discussed the impact of magnetized water on seed germination, vegetative growth, fruit production, soil and pigments of treated plants. Plant growth and development can be improved both qualitatively and quantitatively via irrigation with magnetized water. It can promote seed germination, seedling early vegetative development, improvement of the mineral content of fruits and seeds, the enzyme activity of the soil, improved water use efficiency, higher nutrient content, and better transformation and consumption efficiency of nutrients; it can also mitigate soil salinity. Furthermore, magnetized water had a substantial good influence on the mobility and uptake of micronutrient concentrations, as well as promoted better growth criteria, all of which increased biomass and total yield. Also, irrigating plants with magnetized water resulted in a considerable increase in chloroplast pigments (carotenoids, chlorophyll a, and b) and photosynthetic activity. Magnetizing low-quality water (brackish water, saline water or water contaminated with metals) can be considered as an alternative tool to overcome the problem of scarcity and shortage of water resources. As a result, magnetic treatment of irrigation water could be a promising technique to boost agricultural production while also being environmentally beneficial in the future. The major challenge in using magnetized water in agriculture is creating pumps that are compatible with the technical and practical needs of magnetic systems while also effectively integrating irrigation components. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agriculture / Poljoprivreda is the property of Josip Juraj Strossmayer University of Osijek, Faculty of Agriculture in Osijek and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Salinity is a serious problem in the cultivation of ornamental plants. Chrysanthemum (Chrysanthemum × grandiflorum) 'Palisade White' was evaluated in order to examine its responses to long-term salt stress. Plants were grown in substrate supplemented with NaCl doses (g dm−3 of substrate) 0, 0.44, 0.96, 1.47, 1.98, 2.48 and 2.99. The initial electrical conductivity (EC) of the substrates was 0.3, 0.9, 1.4, 1.9, 2.6, 3.1 and 3.9 dS m−1, respectively. Plant growth, relative water content (RWC), Na, Cl, K, N and P concentrations, membrane injury (MI), chlorophyll and proline levels, as well as gas exchange parameters in leaves of chrysanthemum were determined. A dose-dependent significant reduction of growth and minor decrease of leaf RWC were observed. Foliar Na and Cl concentrations increased with the highest NaCl dose up to 6-fold. However, the concentration of K increased by about 14 %, N by about 5 % but P decreased by about 23 %. Membrane injury was rather low (11 %) even at the highest NaCl dose. Statistically significant decreases of stomatal conductance (20 %), transpiration rate (32 %) and photosynthesis (25 %) were already observed at the lowest NaCl dose and about 40 % decrease of all these parameters with the highest dose. A significant reduction in the intercellular CO2 concentration occurred at the lower NaCl doses and no changes with the highest dose. These results show that in plants grown with the highest NaCl dose, non-stomatal limitation of photosynthesis may occur. According to Maas and Hoffman tolerance assessment (1977) chrysanthemum 'Palisade White' may be considered as moderately sensitive to salt stress in terms of growth inhibition. However, it is able to cope with long-term salt stress without any signs of damage, such as chlorophyll depletion, leaf browning or necrotic spots probably due to maintenance of K homeostasis and proline accumulation, which alleviate the toxic effect of chloride. [ABSTRACT FROM AUTHOR]

To study the mechanism of photosynthetic attenuation in cucumber seedling leaves under low temperature and weak light conditions, using cucumber variety 'Jinyou 101' as experimental material, a two-factor environmental control experiment of low temperature and weak light was carried out by using artificial climate boxes in Nanjing University of Information Science and Technology from 2020 to 2021. The daytime/night temperature was set at 13℃/3℃, 16℃/6℃, 19℃/9℃ and 12℃/22℃, and the photosynthetically active radiation (PAR) was set at 200, 400μmol·m-2·s-1. There were eight treatments, each of which lasted for 3, 6, 9 and 12 days, respectively. The treatment with light and temperature of 28℃/18℃ and 800μmol·m-2·s-1 was used as control (CK). The chloroplast pigment content, photosynthetic parameters, and kinetic parameters of rapid chlorophyll fluorescence induction in cucumber leaves at the seedling stage were measured under different treatments. The results showed that: (1) the chloroplast pigment content of cucumber leaves decreased with the decrease of temperature and PAR, and decreased with the prolongation of treatment time. (2) Under different treatments, the maximum photosynthetic rate (Pmax), light saturation point (LSP), stomatal conductance (Gs), and transpiration rate (Tr) decreased with the increase of stress degree and time, and the light compensation point (LCP) increased with the increase of stress degree and time. The results showed that the deeper the degree of low temperature and weak light stress and the longer the stress time, the weaker the photosynthesis of cucumber leaves. (3) With the deepening of stress and the prolongation of stress time, the JIP phase of the fast fluorescence induction kinetic curve (OJIP curve) of cucumber leaves decreased gradually, the parameters of energy distribution ratio (φPo, ψEo, and φEo) decreased gradually, and the light energy absorbed (ABS/RC) and trapped (TRo/RC) per unit active reaction center gradually increased, but the light energy used for electron transport (ETo/RC) still decreased. This study confirmed that low temperature and weak light treatment reduced the stomatal conductance of cucumber leaves and hindered gas exchange; the antenna pigment content decreased, and the light energy absorbed and captured by the leaves decreased; the performance of PSII decreased, and the energy used for photochemical reactions decreased; therefore, the photosynthesis of the leaves decreased. [ABSTRACT FROM AUTHOR]

Arsenic (As) in groundwater severely harms global economic development by affecting growth and productivity of agricultural crops that causes human health risk. The comparative influence of silicon (Si) and selenium (Se) to modulate pigments levels, photosynthetic parameters using LI-6400XT Portable Photosynthesis System and carbohydrate metabolism under arsenate (As-V) stress in rice cv. MTU-1010 were evaluated. As(V) stress significantly decreased chlorophyll-a (32% on an average), chlorophyll-b (58% on an average), total chlorophyll (46% on an average), fluorescence intensity (31% on an average), carotene (39% on an average), xanthophyll (33% on an average), Hill activity (47% on an average) and the photosynthetic parameters, viz. intercellular CO2 concentration (52% on an average), net photosynthesis (54% on an average), transpiration rate (36% on an average) and stomatal conductance (38% on an average) in the test seedlings. As(V) + Si treatments enhanced the stated occurrences more than As(V) + Se treatments in rice seedlings. Sugar contents, viz. reducing (85% on an average) and non-reducing sugar (61% on an average), were increased, but starch content (57% on an average) was decreased in only As(V)-treated rice seedlings. The activities of carbohydrate metabolizing enzymes were increased, while sucrose synthase activity was decreased due to As(V) toxicity in the test seedlings. Co-application of Si and As(V) as well as Se and As(V) showed ameliorative effects on sugar and starch contents along with the activities of carbohydrate metabolizing enzymes, but more potential effect was observed under combined application of Si and As(V) in rice seedlings. Thus, it is an important purpose of this paper to compare the ability of Se and Si to alleviate As(V) toxicity in rice seedlings which will be an effective approach to develop possible strategies in As-contaminated agricultural soil to improve normal growth and productivity of rice plants. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mechanisms of action of toxic organic compounds (OC) (pentane, hexane, benzene, o-xylene, butyl acetate, and benzopyrene) on the reed fescue Festuca arundinacea Schreb., which is a common plant in urban environments, were studied using pulse–amplitude modulated (PAM) fluorometry, which allowed the photochemical activity of photosystem II (PS II) to be evaluated from the parameters of the kinetic curve of chlorophyll a (Chla) fluorescence induction in vivo. A dose- and time-dependent reduction in the content of hydrophobic membrane-bound chlorophyll pigments was found along with simultaneous accumulation in the leaves of chlorophyllide (Chlde), a phytol-free product of chlorophyll degradation. It was shown that the effective quantum yield [Y(II)] of PS II photochemical reactions decreased mainly at high doses of toxic compounds while the level of photochemical fluorescence quenching (qP) did not change significantly and the coefficient of nonphotochemical quenching (qN) increased significantly to different degrees depending on the type of toxicant and the time of its exposure. A high negative correlation was observed between changes in qN, which characterized the thermal dissipation of absorbed energy, and the content of membrane-bound phytol chlorophyll pigments and carotenoids. On the other hand, changes in qN correlated positively with the content of Chlde formed during treatment with OC. The demand for thermal dissipation of absorbed energy resulting from the action of OC was proportional to the degree of destruction of the chloroplast pigment apparatus. This was confirmed by the positive correlation between qN and the content of Chlde, which possessed a photodynamic effect. Thus, parameter qN can serve as a reliable test for the damaging effect of toxic techogenic OC. [ABSTRACT FROM AUTHOR]

Environmental factors and crop management can influence the characteristics of plant morphology and physiology, altering photosynthetic efficiency and mass accumulation. The study aimed to analyze the contents of leaf pigments in cauliflower cultivated under different conditions of water availability and silicon (Si) applications. The experiment was carried out in a protected environment in the city of Maringá-PR. A randomized block design, in a 3x4 factorial scheme, with three replacement conditions [40, 70 and 100% of crop evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four repetitions. The cauliflower cultivation, cultivar Sharon, was carried out in dystroferric RED NITOSOL. Daily evapotranspiration was determined with a constant level water table lysimeter and water replacement was performed with drip irrigation. Si was applied in split doses in three applications (initial, intermediate and final phases). At flowering, leaf tissue from the upper third of the plant was collected, with pigment extraction performed with pure acetone and determination in a spectrophotometer. At harvest, the leaf area of the plants was determined. Data were subjected to analysis of variance and regression analysis. Cauliflower crop under water-deficient reduces leaf area development and alters chloroplast pigments dynamics. Silicon use in the soil increases leaf development, chlorophyll a and b contents, and reduces carotenoids concentration. Under water stress conditions, silicon addition to the soil improves cauliflower performance. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Grapevine leaves are usually characterized by trichomes, specialized epidermal cells. They are interesting in ampelography and also important for the plant ecological responses in biotic and abiotic interactions. In nature, the trichome development is a genetic trait but it can be modified by pests as eriophyid mites. Colomerus vitis is quite common and its economic value is sometime substantial. Here, we studied the leaf erineum induced by C. vitis on 'Ansonica' ('Inzolia'), an important grapevine cultivar characterized by a low level of leaf trichome coating. To date, the interaction between C. vitis and grape has been investigated in few pedo-climatic conditions and no data are reported in 'Ansonica'. Therefore, our objectives were: (1) the analysis, in a Tuscan environment, of the morphology and histology of trichomes in 'Ansonica' leaves unaffected or affected by C. vitis; (2) evaluation, in mature leaves, of the effects of the mite both on pigment content and chlorophyll a fluorescence parameters. 'Ansonica' was devoid of glandular trichomes but it has been established the presence of few simple trichomes strictly associated with the veins. In the erineal sectors, a dense proliferation of simple trichomes in the abaxial epidermis and the development of hyperplasia in the adaxial surface were observed. Moreover, the leaf sections in the erineal regions were thicker due to an abnormal development of the lacunar parenchyma, and trichome proliferation was also extended to interveinal regions. Leaves with erinea showed a deficient content of carotenoids, in comparison to unaffected leaves. In 'Ansonica' leaves, C. vitis induced a decrease in the steady-state operational efficiency of photosystem II associated to a reduction in photochemical quenching and an increase in non-photochemical quenching values. In leaves with erinea, the reduction of photosystem II efficiency was extended to foliar areas not directly affected by galls. The collected results highlight that 'Ansonica' is susceptible to attacks by C. vitis and in the case of widespread leaf attacks the productive damage should not be underestimated. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Research & Applications in Agricultural Engineering is the property of Lukasiewicz Research Network - Industrial Institute for Agricultural Machinery and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to establish parameters of optimization of the factors such as solid/solvent ratio, stirring speed and extraction time in homogenizer-assisted extraction (HAE) of chlorophyll a, b and total from plantain epicarp (Musa paradisiaca L.) using the Box–Benhken design. The individual effect and the interactions of the process variables (solid/solvent ratio, stirring speed (revolutions per minute, rpm), and extraction time in HAE) on the chlorophyll a, b and total contents in the extract were studied. The optimization was carried out with a Derringer desirability function, and it was found that the optimal extraction conditions included a solid/solvent ratio of 0.025 g/mL, an stirring speed of 13,508 and 90 s of treatment with Ultra-turrax. The corresponding predicted values were 33.67 mg/100 g of chlorophyll a, 32.915 mg/100 g of chlorophyll b and 66.585 mg/100 g of total chlorophyll. Finally, the optimal conditions were experimentally verified, and it was established that extraction with an Ultra-Turrax treatment is more efficient than the conventional method (maceration). [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of post-flowering chilling of sweet cherry (Prunus avium L.) on the content of biochemical parameters in the leaf (chloroplast pigments, sugars and phenolics). The effect of chilling was investigated in two experiments. Potted 2-year-old trees of cv. 'Grace Star' and 'Schneiders' were exposed to one, two or three consecutive overnight chillings at an average air temperature of 4.7 °C (Experiment I), but in the following year only trees of 'Grace Star' were chilled at 2.2 °C (Experiment II), 3 to 7 weeks after flowering. The analysis of the biochemical parameters was performed by high performance liquid chromatography combined with electrospray ionization mass spectrometry. Chilling at 4.7 °C caused little or no stress, while 2.2 °C induced more intense stress with increased zeaxanthin, sugar and phenolic content in leaves, while exposure of trees to higher temperatures and closer to flowering showed no changes. Two or three consecutive overnight chilling periods increased the phenolic content and enhanced the accumulation of zeaxanthin in the leaves. Sucrose, sorbitol, fructose, total sugar, and total flavonoid content in leaves increased within 48 h after chilling. Zeaxanthin epoxidized within 24 h after one and 48 h after one and two consecutive overnight chillings. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the physiological and biochemical responses to three different water regimes in two castor bean genotypes (BRS Energia and BRS Nordestina) with different drought tolerance. After 67 days of sowing and 28 days under different water stress levels, some growth parameters were affected by increased stress, resulting in lower height, root, and shoot biomass, leaf area, and number of mature leaves. The increase in cuticular wax load on leaves was prominent under higher water stress. Triterpene and primary alcohols were the main constituent classes identified, but their content did not change under water deficit. Changes primarily occurred in the n-alkane and fatty acid classes. Water stress caused an increase in hydrogen peroxide and malondialdehyde content, a decrease in soluble protein content, and an increase in the activity of key enzymes of the antioxidant defense system (SOD, CAT, and APX). The BRS Nordestina genotype demonstrated a more efficient protection mechanism against drought compared to BRS Energia. [ABSTRACT FROM AUTHOR]

The 14C incubation method for net primary production (NPP) has limited spatial/temporal resolution, while satellite approaches cannot provide direct information at depth. With chlorophyll‐a and backscatter measurements from BGC‐Argo floats, we quantified year‐round NPP in the western North Atlantic Ocean using both the Carbon‐based Productivity Model (CbPM) and Photoacclimation Productivity Model (PPM). Comparison with NPP profiles from 14C incubation measurements showed advantages and limitations of both models. CbPM reproduced the magnitude of NPP in most cases. However, in the summer the CbPM‐based NPP had a large peak in the subsurface, which was an artifact from the subsurface chlorophyll maximum caused by photoacclimation. PPM avoided the artifacts from photoacclimation, but the magnitude of PPM‐derived NPP was smaller than the 14C result. Different NPP distribution patterns along a North‐South transect in the Western North Atlantic Ocean were observed, including higher winter NPP/lower summer NPP in the south, timing differences in NPP seasonal phenology, and different NPP depth distribution patterns in the summer months. Using a 6‐months record of concurrent oxygen and bio‐optical measurements from two Argo floats, we also demonstrated the ability of Argo floats to obtain estimates of the net community production to NPP ratio, ranging from 0.3 in July to −1.0 in December 2016. Our results highlight the utility of float bio‐optical profiles and indicate that environmental conditions (e.g., light availability, nutrient supply) are major factors controlling the seasonality and spatial (horizontal and vertical) distributions of NPP in the western North Atlantic Ocean. Key Points: Net primary production (NPP) derived from Argo‐based bio‐optical measurements was comparable and complementary to 14C incubation and satellite estimatesBoth Carbon‐based Productivity Model and Photoacclimation Productivity Model have their own advantages and limitationsNPP profiles showed varying seasonal NPP distribution patterns along a North‐South transect in the western North Atlantic Ocean [ABSTRACT FROM AUTHOR]

In all, 26 cultures of the harmful marine dinoflagellate Karlodinium, isolated from Japanese and Philippine coastal waters, were examined using LM, SEM, and molecular phylogeny inferred from ITS and LSU rDNA. Seven Karlodinium species (six from Japan and four from Philippines), K. australe, K. ballantinum, K. decipiens, K. gentienii, K. veneficum, K. zhouanum, and a novel species Karlodinium azanzae sp. nov., were identified based on their morphology and phylogenetic positions. Karlodinium azanzae from Manila Bay, Philippines was further characterized by TEM, HPLC (chloroplast pigment), and bioassay on brine shrimp and other marine zooplankton. Cells of K. azanzae were the largest (mean 25.3 µm long) in Karlodinium, possessed numerous tiny reflective particles, starch grains, and lipid granules, and usually swam at the bottom of the culture vessel. The straight apical structure complex and a ventral pore were common to the genus. The longitudinally elongated nucleus was located at the center, and the yellowish chloroplasts contained an embedded pyrenoid and carotenoid pigments typical of the genus (i.e., fucoxanthin as major carotenoid with its derivatives). TEM revealed a part of the flagellar apparatus, of which the long striated ventral connective is the first report in the Kareniaceae. Phylogenetic trees showed closest affinity of K. azanzae with K. australe and K. armiger. The new species could be differentiated from related species by cell size, position of the nucleus, and characteristic swimming behavior. Lethality of K. azanzae to large zooplankton and micropredation using a developed peduncle was also observed. [ABSTRACT FROM AUTHOR]

Despite summer drought may challenge plant survival in Mediterranean-type ecosystems, the role of reproductive load on drought stress and recovery has been poorly studied in invasive plants, most particularly under natural field conditions. In this study, a highly plastic clonal invasive species, Carpobrotus edulis was used to explore a putative differential response to drought between reproductive (senescent) ramets and non-reproductive ramets. Furthermore, fruit removal was used to assess how alterations on the source-sink dynamics influence plant performance during drought stress and recovery. We examined the variations in chloroplast pigments, antioxidants, lipid peroxidation and cytokinins in leaves of non-reproductive and reproductive ramets (either with intact or fruit-removed ramets) in response to summer drought stress and recovery after rains under Mediterranean field conditions. Results showed that although both ramet types within a C. edulis patch recovered at the end of the summer, increased photoprotective investment was found in leaves from reproductive ramets, thus indicating an increased photoprotective demand associated with reproduction at the ramet level. This response was associated with differentiated cytokinin contents in leaves of reproductive ramets compared to those of non-reproductive ramets. Although leaf senescence was not reversed by the fruit removal, leaves recovered their chlorophyll content after rainfall during late summer in parallel with the accumulation of cytokinins. In conclusion, C. edulis shows a huge plasticity in drought stress responses with a marked compartmentation at the ramet level, which helps at least in part to an efficient recovery from unpredictable water shortage periods in the current frame of climate change. Image 1 • Leaves from reproductive ramets showed increased photoprotection in C. edulis. • No effects were observed after fruit removal during summer drought stress. • Reproductive and non-reproductive ramets recovered at the end of the Mediterranean summer. • Ramet recovery after drought is stronger in patches with higher reproductive effort. [ABSTRACT FROM AUTHOR]

In all, 26 cultures of the harmful marine dinoflagellate Karlodinium, isolated from Japanese and Philippine coastal waters, were examined using LM, SEM, and molecular phylogeny inferred from ITS and LSU rDNA. Seven Karlodinium species (six from Japan and four from Philippines), K. australe, K. ballantinum, K. decipiens, K. gentienii, K. veneficum, K. zhouanum, and a novel species Karlodinium azanzae sp. nov., were identified based on their morphology and phylogenetic positions. Karlodinium azanzae from Manila Bay, Philippines was further characterized by TEM, HPLC (chloroplast pigment), and bioassay on brine shrimp and other marine zooplankton. Cells of K. azanzae were the largest (mean 25.3 µm long) in Karlodinium, possessed numerous tiny reflective particles, starch grains, and lipid granules, and usually swam at the bottom of the culture vessel. The straight apical structure complex and a ventral pore were common to the genus. The longitudinally elongated nucleus was located at the center, and the yellowish chloroplasts contained an embedded pyrenoid and carotenoid pigments typical of the genus (i.e., fucoxanthin as major carotenoid with its derivatives). TEM revealed a part of the flagellar apparatus, of which the long striated ventral connective is the first report in the Kareniaceae. Phylogenetic trees showed closest affinity of K. azanzae with K. australe and K. armiger. The new species could be differentiated from related species by cell size, position of the nucleus, and characteristic swimming behavior. Lethality of K. azanzae to large zooplankton and micropredation using a developed peduncle was also observed. [ABSTRACT FROM AUTHOR]

For investigations of ongoing processes in plants, such as photosynthesis in conifer leaves, nondestructive and noninvasive measuring techniques are needed. In this paper, a novel approach has been developed for the measurement of chloroplasts' numbers and pigment contents in conifer leaves based on the measurements of leaf absorption spectra using optical fibers and an array spectrophotometer. To eliminate the effect of scattering on the measured absorption spectra, a strategy has been applied taking advantage of the combined use of thin optical fibers normal to the needle's longitudinal axis and the phenomenon that scattering is largest in the forward direction. The optical path in the leaf is nearly the distance between the fiber tips; thus, we were able to obtain the absorption spectrum of the pigments in situ. A effect of the measured absorption spectra, occurring due to the organization of pigments in the leaf and interaction between light and leaf interior, can be accounted for by using the so-called Duysens transformation. Using this transformation, pigment contents and the relative number of chloroplasts can be obtained from the measured absorption spectra. We applied the method to observe pigment concentrations in different stages of the greening process in the leaves of two conifer species, Taxus baccata and Picea abies. The presented method may be used to estimate changes in chloroplast number and pigment content during various phases of greening of a species and to observe differences among various species. [ABSTRACT FROM AUTHOR]

The experimental studies were conducted from 2015-2017 years in two cycles. The aim of the research was to determine a better grafting time and a choice of an appropriate rootstock for the propagation of two cultivars of mountain pine (Pinus mugo Turra). The influence of the grafted cultivar and rootstock used on the level of chloroplast pigments in the needles was also checked. The studies concerned two cultivars of mountain pine (Pinus mugo) 'Grześ' and 'Zundert', which were grafted on four different rootstocks: Pinus contorta (Dougl. ex Loud.), Pinus nigra (Arn.), Pinus sylvestris (L.) and Pinus mugo subsp. uncinata (Ramond Domin) in two dates: 20 January and 15 March. The highest percentage of graft success was obtained for the two cultivars on Pinus uncinata and Pinus contorta rootstocks. A later term of grafting procedure affected bigger effectiveness of grafting of the two studied cultivars, except for the graft success on Pinus sylvestris rootstock. The highest increments of side shoots and lengths of main stems for 'Grześ' cultivar were obtained on Pinus nigra, and for 'Zundert' the influence of the rootstock on the above mentioned parameters was not evident. No significant differences in the number of increments in the first and second year of studies were observed. The highest level of chlorophyll A and B was found in the needles of 'Grześ' cultivar, independently from the rootstock used. Among tested rootstocks, only Pinus nigra had a significant impact on a higher content of chlorophyll B in the needles of the studied cultivars of mountain pine trees. [ABSTRACT FROM AUTHOR]

In nature, foliar variegation has varied origins, and can be ascribed to two major mechanisms: pigment-related variegation and structural variegation caused by the optical properties of leaf structure. However, understanding of these mechanisms is still lacking, and structural mechanisms are often misinterpreted. In this study, six variegated plants native to Taiwan and two ornamental plants, with novel and unusual foliar variegation patterns, are studied to reveal their mechanisms of variegation. Two newly understood variegation patterns, the silvery white leaf surface of Begonia aptera and the varnish on basal leaflets of Oxalis corymbosa, are reported here. White to light green patches on leaf surfaces characterize the foliar variegation in the other six study species, Nervilia nipponica, O. acetosella subsp. griffithii var. formosana, Paphiopedilum concolor, Selaginella picta, Smilax bracteata subsp. verruculosa and Valeriana hsuii. All six Taiwan native plants exhibit structural variegation, five of which have air space type variegation. Surprisingly the silvery white leaf surface of B. aptera results from numerous sand-like white spots caused by intercellular space. The varnish on leaves of O. corymbosa is the epidermis type of variegation comprised of two newly identified subtypes, larger epidermal cells and thicker outer cell walls. The two ornamental plants have variegation caused by pigments: the chloroplast type from fewer chloroplasts in P. concolor and the chlorophyll type, from absence of chloroplasts in S. picta. This study extends understanding of the mechanisms of natural foliar variegation, illustrating the diversity of mechanisms by which plants may change the appearance of their leaves. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pine resin, a valuable secondary metabolite, is derived from the products of photosynthesis. Pine needles, serving as the primary organ for photosynthesis and nutrient absorption, facilitate the continuous transport of nutrients to all plant organs through photosynthesis. The functional traits of pine needles exhibit a close association with the photosynthetic efficiency of pine trees, thereby affecting resin yield. The selection of superior trees with high-resin yield (RY) for slash pine (Pinus elliottii Engelm.) faces difficulties due to low selection efficiency and a high false selection rate caused by the absence of reliable indirect selection traits. The objective of this study was to systematically investigate the relationships between slash pine needle functional traits and RY in different regions. Understanding the relationship between functional traits of pine needles and RY is essential for addressing the challenges mentioned above. There were positive correlations between RY and most morphological traits, except for leaf dry matter content (LDMC), which showed a negative correlation. Moreover, low-resin yield trees exhibited lower values for most morphological variables, except for LDMC. High-yield trees exhibited higher stomata number per mm2 (STN), larger stomata diameter (STD) and size (STS), and stomata area per mm2 (STA) across all periods and sites when compared with low-yield individuals. Chloroplast pigment component analysis revealed that high yielders exhibited higher levels of chloroplast a (CHL a) and chloroplast a+b (CHL a+b) compared to low yielders, and positive correlations were found between resin yield and CHL a, chloroplast b (CHL b), and CHL a+b. Higher nutrient contents were observed in high resin yield individuals, and positive correlations were found between resin yield and most nutrients, except for potassium (K). Different needle functional traits exhibited varying periodic patterns of resin production. Most needle functional traits could be useful criteria for evaluating resin production in slash pine breeding programs, which could improve the efficiency of breeding, shorten the breeding cycle, and accelerate the breeding process. • Correlations between functional traits and resin yield aid slash pine breeding. • Higher morphological and stomatal trait values are observed in high yielders. • Certain chloroplast pigments positively impact resin yield. • Nutrient contents correlate with resin yield, highlighting their importance. • Periodic patterns of resin production vary with needle functional traits. [ABSTRACT FROM AUTHOR]

Experimental studies were conducted in 2015-2017 in the Department of Dendrology, Pomology and Nursery of Poznan University of Life Sciences. The aim of the research was to study the usefulness of three rootstocks: Larix decidua, Pinus armandii, Cedrus deodara and two grafting methods: side grafting and split grafting for propagation purposes of Cedrus deodara 'Karl Fuchs'. In addition, it was evaluated how the rootstock and the age of cultivar shoots influenced the level of chloroplast pigments in the needles. A higher percentage of grafts success was obtained on Pinus armandii and Cedrus deodara using the side grafting method. Grafted scions of 'Karl Fuchs' produced the greatest number of lateral buds and the longest lateral increments of growth on Cedrus deodara root stock. Side grafting significantly improved the percentage of plants that restarted their growth in the second year of cultivation. The largest number of buds on two-year-old shoots were counted on plants grafted on Cedrus deodara using split grafting method. The rootstocks used in this experiment had a slight effect on the content of chloroplast pigments in the needles. Plants grafted on Pinus armandii had the highest level of chlorophyll B, and those grafted on Larix decidua - chlorophyll A/B ratio. The content of chloroplast pigments in the needles depended on the age of shoots. The highest level of chlorophyll A, chlorophyll B and carotenoids was observed when needles were collected from the last year's growth. [ABSTRACT FROM AUTHOR]

Analysis of a long-term (1994-2014) data set of phytoplankton and zooplankton in the deep, dimictic, oligo-mesotrophic Lake Stechlin (Germany) revealed trend-like changes: phytoplankton biomass and resource use efficiency increased with proliferation of heterocytic cyanobacteria (Dolichospermum spp. and Aphanizomenon flos-aquae), and those of especially large-sized zooplankton (Eudiaptomus, Eurytemora) decreased. These reverse trends are clear eutrophication symptoms and suggest a long-term trophic decoupling with potential decrease in energy transport towards higher tropic levels. Total phosphorus increased significantly over time; however, there is no known external P load for Lake Stechlin. Causality analysis enabled us to identify the primary reason of the observed changes. According to the results, stronger and longer-lasting stratification (measured as relative water column stability) drove the observed changes and the gradual regime shift was initiated by an extreme weather event—both indicating that climate change has been the crucial driver of the planktic community in this lake. Our study also documents that there might be decadal delays between cause and consequences in aquatic food webs, supporting the essential importance of long-term monitoring efforts. [ABSTRACT FROM AUTHOR]

Highlights • Chlorophyll size was reduced by atmospheric and room temperature plasma. • Algal mutant grew as lighter green colonies on agar plate. • Algal mutant had much lower chlorophyll content per unit cell volume. • Algal mutants produced 356.5–405.2 mL L−1 H 2 when grown in co-cultures. • Genes relating to photosynthesis had higher expressions in mutant cells. Abstract Reduction of chlorophyll size has great advantages on improving the photosynthesis efficiency as well as the photolysis algal H 2 production. To promote the H 2 production, Chlamydomonas reinhardtii was mutated by atmospheric and room temperature plasma (ARTP). After the selection, an algal mutant was observed to have 1.8–5.2 times (28.5–84.1 mL L−1) and 2.7–3.1 times (356.5–405.2 mL L−1) higher H 2 production than wild-type during the algal subcultures grown in pure and co-cultures, respectively. In comparison with wild-type alga, the mutant grew as lighter green colonies on agar plate, with about 2 times larger cell diameter and 5.3–6.1 times lower chlorophyll content per unit cell volume. Results from the comparative transcriptomic analysis indicated that most of the genes relating to photosynthesis (photosystem I, II, cytochrome b6/f complex, photosynthetic electron transport, and F-type ATPase) and LHC proteins were have higher expressions in mutant cells, suggesting the improvement of photosynthesis efficiency. [ABSTRACT FROM AUTHOR]

Climate warming is subjecting plants to heat stress, which can affect their physiological processes thereby impacting their growth, development, and productivity. Potato (Solanum tuberosum L.) is a staple food worldwide, but potato crops are very sensitive to heat stress. We have studied the effects of heat stress on the leaf chlorophyll content, plant growth, and tuber yield of 55 commercial potato cultivars in clonal tests under heat-stress conditions [HS; 35 °C (day), 28 °C (night)] and control (non-stress) conditions [CK; 22 °C (day), 18 °C (night)]. The potato cultivars varied in their response to heat stress. Overall, heat stress reduced leaf size, increased the SPAD index values for leaf chlorophyll by up to 65%, and increased plant height by 64%, but severely reduced (by 93%) the mass of the largest tuber. The HS:CK SPAD ratios positively correlated with the HS:CK plant height ratio, mass of the largest tuber under heat stress, and the HS:CK ratio for mass of the largest tuber. Potato cultivars displayed a correlated response to heat stress for their leaf chlorophyll content, plant height, and tuber mass. We have identified the most heat-tolerant and heat-susceptible cultivars for these traits. Under heat-stress conditions, potato cultivars tend not to show as much reduction in tuber mass if the plants have greater increases in leaf chlorophyll content and plant height. [ABSTRACT FROM AUTHOR]

The green tissue in the culm of bamboo, engaging in photosynthesis, supplies carbohydrates to support the rapid growth of its shoots, yet the molecular basis for the chlorosis of bamboo culm tissue has not been elucidated. In contrast to the wild-type moso bamboo (Phyllostachys edulis f. pubescens , MB) with integral-green internodes at culms, the mutant one (P. edulis f. luteosulcata , YM) has typical bicolor internodes with yellow slot and green wall. By pigment quantification and chloroplast ultrastructure investigation, we found that the chlorosis in YM slot was caused by chlorophyll a deficiency, defective stroma thylakoids and misalignment of grana thylakoids. Based on transcriptomic comparisons across yellow and green tissues, the expression of plentiful genes involved in chloroplast components were significantly deceased in the tissue of YM slot, including genes associated with chloroplast development and chlorophyll metabolism. Analysis of differentially expressed genes and a multilayered hierarchical gene regulatory network both suggest that the decreased expression of BBX15 s (B-BOX ZINC FINGER PROTEIN 15 s) is likely the underlying cause of thylakoid dysgenesis and chlorophyll deficiency in the YM slot. This was further corroborated by Yeast one-hybrid (Y1H) assays and transgenic validation experiments, which demonstrated that BBX15s can directly regulate the transcription of genes related to chloroplast development and chlorophyll synthesis. This study provides insight into the mechanism of moso bamboo culm chloroplast development and serves as a productive basis for further exploration of bamboo culm coloration. • Chlorophyll a deficiency and thylakoid agenesis cause the chlorosis of culm slot. • Coloration discrepancy between YM and MB results from transcriptional differences. • PeBBX15s facilitate the transcription of thylakoid membrane protein genes. [ABSTRACT FROM AUTHOR]

Application of per- and polyfluoroalkyl substances (PFASs) is shifting to short-chain analogs (C ≤ 6) that raises concerns for their potential ecotoxicological risks. In the present study, pot experiments were carried out to study the effects of perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs), with different carbon chain lengths (C4, C6, and C8) on the growth of wheat seedlings and their plant uptake and transfer at two spiking levels (200 and 2000 μg/kg soil). Exposure to C4 PFAAs slightly inhibited chlorophyll activity, whereas exposure to C8 PFAAs showed enhancement. The bioaccumulation factors (BAFs) for C4 PFAAs in wheat were over 10, while BAFs for C8 PFAAs were all below 1. Rhizospheric and root to shoot transfer factors for PFAAs were both negatively correlated with their log Kow (p < 0.05). PFCAs exhibited both higher rhizospheric mobility and accumulation potentials than PFSAs of the same chain lengths. Hence, perfluoroalkyl chain governs the mobility of PFAAs in a soil-plant system besides interactions of their head groups, and the substitution with shorter chain PFASs raises concerns for their higher plant accumulation potential that brings higher ecotoxicological and human exposure risks via food chains. [ABSTRACT FROM AUTHOR]

Gall-inducing insects may cause multiple physiological changes in host plants, such as the loss of photosynthetic pigments and reduced photosynthetic capacity. However, the direction of these changes is usually insect species-dependent. Therefore, the objective of this research was to characterize the indirect effects of galls induced by asexual generation of Neuroterus numismalis (Fourc.) and N. quercusbaccarum L. on photosynthesis by comparing changes in photosynthetic and photoprotective pigments and chlorophyll a fluorescence in foliar tissue with and without galls in naturally growing pedunculate oak trees (Quercus robur L.). The presence of galls of both Cynipidae species caused a significant decrease of chlorophyll a, b and carotenoids contents. Moreover, photosynthetic parameters (F0, Fm, Fv/Fm, Y, qP, qN) were significantly decreased. These results provide valuable information for diagnosing the oak infections using a noninvasive method, such as chlorophyll a fluorescence and predicting the effect of infections on photosynthetic productivity. [ABSTRACT FROM AUTHOR]

The synergy of Tubifex tubifex ( T. tubifex ) and mussels on SFCWs (named SFCW-MT) performance was well studied in laboratory throughout a year. The SFCW-MT were steady operated with high TN and TP treatment, with the removal efficiencies of 37.85 ± 5.22% and 39.26 ± 5.20% even in winter. The mussels had excellent NH 4 -N removal efficiency, and avoid the shortage of NH 4 -N removal with T. tubifex in winter. Simultaneously, the SFCW-MT improved the NO 3 -N treatment by 51% than that in control group. The plant growth was improved in SFCW-MT, which reflected in the improvement of total chlorophyll contents and plant heights. The N and P absorbed by wetland plants and adsorbed by substrate were both increased with mussels. Microbial analysis results revealed that, the mussels could keep the abundance of nitrifiers despite the negative effect of T. tubifex . On that basis, the improved proportions of denitrifiers ( Firmicutes ) have a significantly recognized role in NO 3 -N transformation in SFCW-MT. The gut and membrane sections of mussels, as well as T. tubifex , also has proportions of denitrifiers and part of nitrifiers, and thus changed the microbial community in substrate. This evidence indicated that the co-existence of T. tubifex and mussels have potential application for simultaneous removal of NH 4 -N and NO 3 -N in CWs. [ABSTRACT FROM AUTHOR]