Evaluation of the Effect of Paclobutrazol Foliar application under Cold Stress Conditions on Amount of Soluble Carbohydrates and Rice Yield cv Hashemi

Abscisic acid and chilling acclimation improve cold tolerance in rice seedling plants by modulating the antioxidative defense system

The Frank–Starling mechanism and thermal stress: fundamentals applied!

The results of three-year research (2016–2019) conducted in the fields of the State Enterprise Experimental Farm "Dnipro" of the SЕ Institute of Grain Crops of NAAS of Ukraine with soft winter wheat was presented. The soft winter wheat was placed on black fallow (on background of N30P60K30) and after sunflower (on background of N60P60K60). It was found that winter wheat plants had a not the same ability to accumulate soluble carbohydrates in years with different weather conditions. The analysis of plant samples showed that the largest number of these substances had synthesized in the autumn 2017. It was found that in the plots with black fallow during the period from November 20, 2017 to January 10, 2018, the amount of soluble carbohydrates (total amount of mono- and disaccharides) in the tillering nodes of winter wheat plants of Uzhynok variety decreased from 41.2 % to 34.7 % (by 6.5 %), Nyva Odeska variety – from 43.9 % to 32.7 % (by 11.2 %), Kokhanka variety – from 45.0 % to 42.6 % (only by 2.4 %). From January 10 until the resumption of spring vegetation, the carbohydrates were consumed most intensively by plants of the Uzhynok and Kokhanka varieties. It was found that despite the lower doses of mineral fertilizers applied to presowing cultivation, winter wheat plants accumulated more soluble carbohydrates in all years after black fallow than after sunflower. On average for three years of research, the highest consumption of sugars during the winter both in leaves and in tillering nodes, regardless of the forecrop, was observed in plants of the Uzhynok variety. It was found that the winter wheat plants of Kokhanka variety consumed soluble carbohydrates more economically than the Uzhynok and Nyva Odeska varieties, and grew more intensively in early spring. The content of sugars in the tillering nodes of Kokhanka variety during resumption of spring vegetation was 28.4 % for black fallow and 25.9 % after non-fallow forecrop. Key words: winter wheat, variety, soluble carbohydrates, forecrop, background of nutrition.

The metabolic activity of phytohormones and the accumulation of carbohydrates affect the reactivation of the cambial zone and the radial increment of woody plants. We aimed to monitor the dynamics of indole-3-acetic acid (IAA) concentration and amounts of soluble carbohydrates during xylem and phloem formation of one growing season (2015). Six sample trees of Scots pine (Pinus sylvestris L.), aged 80 years on average, growing in the Sobešice research site (404 m a.s.l.) in the Czech Republic were selected. We obtained microcore samples at weekly intervals by the Trephor tool method for cell formation analysis and spectrophotometric determination of IAA and soluble carbohydrate contents. We found that time of the highest concentration of IAA (last week of April) coincided with time of the maximum number of cells in the cambial zone and highest expansion of the cell enlargement stage. When the IAA concentration was too low to be measured, latewood tracheids started to form, and late phloem sieve cell formation ceased. The highest concentration of soluble carbohydrates was 200.40 ± 21.6 µg GLU per sample (May 14). This coincided with the fastest weekly xylem cell increment. This research shows that IAA and soluble carbohydrate dynamics directly affects xylem and phloem formation.

Cold stress is one of the major abiotic stress factors influencing photosynthesis in rice. In the present study, a linkage analysis and genome-wide association study (GWAS) of photosynthesis-related traits (PRT) at the grain filling stage of rice, including net photosynthetic rate (Pn), stomatal conductance (Sc), transpiration rate (Tr), and intercellular CO2 concentration (Ci), were performed under cold stress using a recombinant inbred line population and single-nucleotide polymorphism (SNP) re-sequencing data of 295 japonica varieties. Twenty-nine additive QTLs (A-QTLs) were detected, and 17 out of the 29 QTLs were cold stress-related. qPn7-1, qTr1, qTr7-1, qTr7-2, qCi7-1 and qSc7-1 were specifically expressed under the cold stress and control conditions in different years, with one major pleiotropic QTL interval (RM1306–RM70) detected. In addition, additive × environment interaction QTLs revealed that qPn7-1, qTr1, qTr7-1, qCi7-1, qSc7-1, and qSc8-1 were influenced mainly by genetic factors, suggesting they could be exploited in cold tolerance breeding activities. Ten SNPs were associated significantly with PRT under cold-water stress based on GWAS, and three out the ten were included in the major QTL interval of RM1306–RM70, verifying the QTLs detected in multiple environments by linkage analysis. According to the major QTL genotypes linked to PRT, phenotypically superior RIL47 could be considered for genetic improvement of PRT under cold water stress. The results could facilitate the fine mapping of QTLs related to Pn, Tr, Ci, and Sc under the cold stress condition through the marker-assisted selection approaches.

Seasonal changes of carbohydrates metabolism in apple trees

The effects of salinity (0, 50, 100, 150, and 200 mM NaCl) and heat-shock (42°C) and their interactions on germination, seedling growth, and some relevant metabolic changes of two cultivars (cv. Giza 155 and cv. Stork) of wheat (Triticum vulgaris L.) were studied. Germination studies indicate that plants tolerated salinity up to 100 mM NaCl. The lengths of roots and shoots and their water content, as well as fresh and dry matter yield of cv. Giza 155 seedlings remained more or less unchanged up to 100 mM NaCl and of cv. Stork up to 50 mM NaCl. Salinity induced progressive increase in soluble carbohydrates, soluble proteins and proline in cv. Giza 155 and in soluble proteins, proline and other free amino acids in cv. Stork. However, under the higher salinity levels, in cv. Giza 155 increase in soluble carbohydrates was accompanied by lose in other free amino acids, whereas in cv. Stork an opposite effect was obtained. Heat-shock treatment (42°C for 24 h) induced a significant decrease in the final germination percentage, the shoot and root lengths, fresh matter yield and the water content. The dry matter yield of the two cultivars was considerably increased as compared with the corresponding treatments with NaCl only. Heat-shock treatment resulted in a significant increase, in the amount of soluble carbohydrates and proline in salt treated seedlings of both cultivars. The pattern of changes in amino acids was opposite to that of soluble proteins, indicating that the increase in soluble proteins was at the expense of other amino acids in cv. Giza 155 andvice versa in cv. Stork.

Sunflower plants (Helianthus annuus L.) grown at 30 °C were cooled to 13 °C in the light in atmospheric C02 or low C02, or in darkness. Photosynthetic rate at 30 °C after cooling whole plants in atmospheric C02 for 12 h during a photoperiod was significantly lower than at the start of the photoperiod compared to plants cooled at low C02, those cooled in the dark and those maintained at 30 °C. Amounts of sucrose, hexoses and starch in leaves at 13 °C increased throughout a 14 h photoperiod to levels higher than in leaves at 30 °C, where amounts of sucrose and hexoses were stable or falling after 4 h. Carbohydrate accumulation at 13 °C during this photoperiod was more than twice that at 30 °C. After three photoperiods and two dark periods at 13 °C carbohydrate levels in leaves were still as high as at the end of the first photoperiod, but less carbohydrate accumulated during the photoperiods than during the first photoperiod, and more was partitioned as starch. Amounts of soluble carbohydrate in roots were greater after 14 h at 13 °C than in roots of plants at 30 °C. Loss of 14C from leaves at 30 °C as a proportion of 14C02 fixed by them at 30 °C, decreased after exposure of plants to 13 °C in the light for 30 min prior to 14C02feeding. Results indicate an effect of cold on the transport process that was light-dependent. It is inferred that the reduction in the proportion of 14C lost from leaves after 10 h cooling was due to reduced sink demand, whereas the rise in the proportion of 14C lost from leaves after 24 h reflects reduced photosynthetic rate. The coincidence of reduced photosynthetic rate with raised carbohydrate levels in leaves maintained at 30 °C throughout, whilst the rest of the plant was cooled to 13 °C in the light implies feedback inhibition of photosynthesis. This may reduce the imbalance between source and sink in sunflower during the first days of long-term cooling.

Cold stress (low temperature stress) is one of the abiotic stress factors. It causes many morphological and physiological problems in plants. One of the applications to eliminate and alleviate these negative effects is molybdenum application. The aim of this study was to determine the effect of molybdenum application on cold stress in commercial variety Mazamort pepper. In the experiment, control, 25 ppm molybdenum concentration, 72 hours cold stress and 25 ppm molybdenum +72 hours cold stress applications were included. Pots of 2 L were used to grow the plants and the growing medium was a mixture of peat and perlite in a ratio of 2:1 by volume. Climatic chamber conditions were set to 24±1°C during the day and 18±1°C at night with 16/8 h light/dark photoperiodicity for control conditions and 24±1°C during the day and 5±1°C at night with photoperiodicity for cold stress conditions. The experiment was planned according to the random plots factorial design with 3 replications and 6 plants in each replicate. At the end of the study, plant height, stem diameter, number of leaves, plant fresh and dry weight, SPAD, wet basis moisture content, leaf proportional water content and ion leakage parameters were analysed. The highest plant height of Mazamort pepper variety was determined in 25 ppm molybdenum+72 hours cold stress application (44.51 cm). Application of 25 ppm molybdenum was effective in alleviating the negative effect of cold stress on plant stem diameter, plant fresh-dry weight and turgor potential. Moisture content wet basis was lowest in 25 ppm molybdenum +72 hours cold stress application. SPAD value in pepper plants decreased under cold stress conditions. It was observed that 25 ppm molybdenum application was ineffective and the decrease increased under cold stress conditions. Ion leakage in Mazamort pepper variety was highest under 72 hours cold stress and 25 ppm molybdenum +72 hours cold stress conditions. Under cold stress conditions, 25 ppm molybdenum application was ineffective. Molybdenum application under cold stress conditions was found to have positive effects on some parameters in general. In future studies, we believe that the application of different molybdenum concentrations and different cold stress periods will reveal the effects of molybdenum more clearly.

In order to reduce the damage caused by the late-season drought stress of canola, a factorial split-plot experiment was performed based on the randomized complete blocks design with three replications in Karaj, Iran. The treatments were Potassium sulfate in two levels, including application and non-application of potassium sulfate, irrigation at three levels including normal irrigation (control), restricted irrigation from the flowering and pod formation stage, as factorial were in main plots and winter canola cultivars including Opera, L72, KR1, GKH3705, GKH0224 were in subplots. The simple effect of irrigation and potassium sulfate on all of the studied traits and the simple effect of cultivar on all traits except chlorophyll b were significant. The interaction effect of irrigation × cultivar on soluble carbohydrate, stomatal resistance, proline content, chlorophyll a and total chlorophyll content was significant. The interaction effect of irrigation × potassium sulfate on the amount of soluble carbohydrates, stomatal resistance and proline content of leaves was significant. In irrigation interruption from the pod formation stage, the promising line of L72, and in irrigation interruption from the flowering stage, the Neptune cultivar exhibited the most positive effect of potassium application on the studied traits. As a result, the application of potassium sulfate in addition to the L72 and Neptune cultivars is recommended in areas similar to the tested area encountering the late-season drought stress.

Healing and acclimatization are critical in vegetable grafting under controlled environments. Here, we investigated the impacts of LED light qualities on the morphological traits and photosynthetic performance of grafted tomato seedlings. Seeds of the tomatoes “DRW 7806 F1” and “Maxifort” (Solanum lycopersicum × Solanum habrochaites) used as scion and rootstock were planted in 104-cell plug trays into a mixture of cocopeat and perlite (volume ratio: 3 to 1). Survival ratio, above- and underground growth, photosynthetic performance, soluble carbohydrate content, pigmentation, and antioxidant enzymes activity were evaluated following 20 days of exposure to different light qualities, including white (35% B, 49% intermediate spectra, 16% R) light as control, blue, red, and a combination of red (68%) and blue with the same light intensity of 75 ± 5 µmol m−2 s−1. The lowest scion diameter, leaf area, root and shoot dry weight, SPAD value, and the highest scion length and amount of soluble carbohydrate were detected in R-exposed seedlings. Moreover, R-exposed seedlings showed leaf epinasty and reduced photosynthetic performance. On the other hand, RB-exposed seedlings showed the highest leaf area, shoot and root dry weight, plant fresh and dry weight, scion stem diameter and photosystem II efficiency. In addition, superoxide dismutase activity was increased in R-exposed seedlings, while guaiacol peroxidase activity was enhanced in seedlings grown in RB. In conclusion, a combination of R and B is suggested as the suitable light spectrum to promote plant growth and photosynthetic performance in grafted tomato seedlings.

Bioethanol production from dilute acid hydrolysis of cassava peels, sugar beet pulp, and green macroalgae (Ulva lactuca)

Mechanism of starch gelatinization and polymer leaching during microwave heating

SUMMARYChanges in activities of soluble and insoluble acid invertases and in concentrations of ethanol‐soluble carbohydrates were examined during development of the third leaf of oat. The leaves did not contain any alkaline invertases. High activity of soluble invertase, high concentrations of reducing sugar and low concentrations of sucrose occurred in the non‐emerged lamina, enclosed by the sheaths of older leaves. In the developing emerged region, activity of soluble invertase rapidly declined to a steady state in the mature leaf. In this tissue, the concentration of total soluble carbohydrate was initially low but increased as the leaf matured and sucrose was always the predominant sugar. The activity of insoluble acid invertase remained relatively constant throughout leaf development. When invertase activities and amounts of soluble carbohydrates were compared in apical and basal regions of the mature leaf after ligule emergence, higher levels of both soluble and insoluble invertase, and total soluble carbohydrates, occurred in the apical half of the leaf.

Seasonal trends of starch and soluble carbohydrates in fruits and leaves of ‘Abbé Fétel’ pear trees and their relationship to fruit quality parameters