Germination Of Sorghum Seeds Research Articles

Does integrative effects of glyphosate, gibberellin and hydrogen peroxide ameliorate the deleterious effects of the herbicide on sorghum seed through its germination?

We investigated the interconnected roles of reactive oxygen species (ROS) generated upon seed exposure to glyphosate and/or gibberellic acid (GA3), and the possible interaction between the herbicide and the plant hormone during germination of sorghum seeds. GA3 decreased antioxidant enzyme activity in embryos, and the over accumulation of hydrogen peroxide (H2O2) in 1000 mM GA3-treated seeds resulted in the lowest germinability among treatments. The deleterious effects of glyphosate on germination rate, in contrast, were not related to H2O2 accumulation, but to its interference with the mitochondrial electron transport chain. However, interactions among glyphosate, GA3 and H2O2 during seed germination were observed. Similar to paclobutrazol, glyphosate appears to interfere with the de novo synthesis of gibberellin, which modulates seed germination through oxidative metabolism. Seeds experiencing increased oxidative status due to GA3 (100 mM) or H2O2 (50 mM) applications had the effects of glyphosate on germination rate reversed. Since decreased ATP synthesis is a secondary effect of glyphosate, increased H2O2 concentrations in embryos must facilitate germination by decreasing the energy required by ATP-demanding metabolism. Our results showed that glyphosate affect seed germination of sorghum, and that the herbicide interacts with oxidative and gibberellin metabolisms.

Effect of seed invigorations on seed quality and storability on sorghum (Sorghum bicolor (L.) Moench) seeds

The study was conducted on sorghum variety HJ 513 to know the effect of seed invigoration on seed quality and storability of sorghum seeds in Department of Seed Science andTechnology, CCS HAU, Hisar during 2016-17. All the treatments studied enhanced the seed quality parameters except the seed treated with castor oil, neem oil and sesame oil. Negative effect of these oils was observed on the seed quality parameters. Maximum germination (78.00percentage) was observed in the seeds treated with KNO3 (1percentage) followed by the seeds treated with K2HPO4 (2percentage) (75.67percentage) while minimum was recorded in the seed treated with sesame oil (16.33percentage) followed by seeds treated with castor oil (39.00percentage) after 12 months of storage. Same trend was also observed in other seed quality parameters also. No insect infestation was observed in any treatment during storage. It has been concluded from the study that germination of sorghum seeds can be maintained above IMSCS (75percentage) upto one year by treating the seed with KNO3 (1percentage) and K2HPO4 (2percentage) and never treat the seeds with castor, neem and sesame (til) oil as these oils adversly affect the germination.

Purification and biochemical characterization of a β-cyanoalanine synthase expressed in germinating seeds of Sorghum bicolor (L.) moench

Abstract Background β-Cyanoalanine synthase plays essential roles in germinating seeds, such as in cyanide homeostasis. Methods β-Cyanoalanine synthase was isolated from sorghum seeds, purified using chromatographic techniques and its biochemical and catalytic properties were determined. Results The purified enzyme had a yield of 61.74% and specific activity of 577.50 nmol H2S/min/mg of protein. The apparent and subunit molecular weight for purified β-cyanoalanine synthase were 58.26±2.41 kDa and 63.4 kDa, respectively. The kinetic parameters with sodium cyanide as substrate were 0.67±0.08 mM, 17.60±0.50 nmol H2S/mL/min, 2.97×10−1 s−1 and 4.43×102 M−1 s−1 for KM, Vmax, kcat and kcat/KM, respectively. With L-cysteine as substrate, the kinetic parameters were 2.64±0.37 mM, 63.41±4.04 nmol H2S/mL/min, 10.71×10−1 s−1 and 4.06×102 M−1 s−1 for KM, Vmax, kcat and kcat/KM, respectively. The optimum temperature and pH for activity were 35°C and 8.5, respectively. The enzyme retained more than half of its activity at 40°C. Inhibitors such as HgCl2, EDTA, glycine and iodoacetamide reduced enzyme activity. Conclusion The biochemical properties of β-cyanoalanine synthase in germinating sorghum seeds highlights its roles in maintaining cyanide homeostasis.

Activities of Carbon and Nitrogen Metabolism Enzymes during Germinating Sorghum Seeds and Early Seedlings Growth

Carbon and nitrogen metabolism are regulated by complex mechanisms in order to optimize growth and development of plants and play a major role during germination and post-germinative growth. The objective of the current work was to establish the degree of changes in activities of key enzymes implicated in these two metabolism pathways during germination and post-germinative growth such as; glutamine synthetase, glutamate dehydrogenase, phosphoenolpyruvate carboxylase, malate dehydrogenase, isocitrate dehydrogenase and aspartate aminotransferase. We have observed that during germination and seedlings development the most activities of nitrogen and carbon metabolism enzymes were correlated (nearly show similar kinetic changes) and influenced by their cellular environment and developmental stage. Therefore, higher activities of these enzymes were observed in the seed, root and shoot at early stages of the post-germinative phase could be effectively linked to the demand of de novo proteins to ensure a good development of seedlings.

Characteristics of different types of biochar and effects on the toxicity of heavy metals to germinating sorghum seeds

Soils contaminated with heavy metals are often notably nutrient poor and unsuitable for plant growth. The addition of biochar can significantly improve soil properties. In this study, the contents of organic compounds and inorganic elements in biochar and the effect of biochar on plant germination were examined. The PAH content of biochar from four different sources was examined, and naphthalene, phenanthrene, fluoranthene and pyrene were identified as primary compounds. The most abundant inorganic elements were potassium, calcium, magnesium, sodium, aluminium, iron and manganese, with strontium and barium also being significantly elevated. The pH of biochar from all sources was strongly alkaline. The sorption characteristics for heavy metals (Cd, Cu and Pb) were also tested for the different types of biochar. Adsorption data were well-described by a Langmuir isotherm with maximum Cd (II), Cu (II) and Pb (II) adsorption capacities of 20.16, 7.83 and 70.92mg/g for bamboo-derived biochar; 18.80, 13.85 and 200mg/g for rice husk-derived biochar; 11.63, 20.08 and 123.46mg/g for ash tree-derived biochar; and 15.11, 10.86 and 196.08mg/g for beech tree-derived biochar, respectively. The effect of biochar on the toxicity of heavy metals was measured by the inhibition of sorghum seed germination. With biochar, the toxicity of cadmium, copper and lead was reduced. Bamboo-derived biochar was less efficient in reducing the toxicity of cadmium and copper compared with the other types of biochar. For lead, the rice husk-derived biochar was the least efficient in reducing the toxicity.

New insights into the post-translational modification of multiple phosphoenolpyruvate carboxylase isoenzymes by phosphorylation and monoubiquitination during sorghum seed development and germination.

Phosphoenolpyruvate carboxylase (PEPC; E.C. 4.1.1.31) was characterized in developing and germinating sorghum seeds, focusing on the transcript and polypeptide abundance of multiple plant-type phosphoenolpyruvate carboxylase (PTPC) genes, and the post-translational modification of each isoenzyme by phosphorylation versus monoubiquitination during germination. We observed high levels of SbPPC4 (Sb07g014960) transcripts during early development (stage I), and extensive transcript abundance of SbPPC2 (Sb02g021090) and SbPPC3 (Sb04g008720) throughout the entire life cycle of the seed. Although tandem mass spectrometry (MS) analysis of immunopurified PTPC indicated that four different PTPC isoenzymes were expressed in the developing and germinating seeds, SbPPC3 was the most abundant isozyme of the developing seed, and of the embryo and the aleurone layer of germinating seeds. In vivo phosphorylation of the different PTPC isoenzymes at their conserved N-terminal seryl phosphorylation site during germination was also established by MS/MS analysis. Furthermore, three of the four isoenzymes were partially monoubiquitinated, with MS/MS pinpointing SbPPC2 and SbPPC3 monoubiquitination at the conserved Lys-630 and Lys-624 residues, respectively. Our results demonstrate that monoubiquitination and phosphorylation simultaneously occur in vivo with different PTPC isozymes during seed germination. In addition, we show that PTPC monoubiquitination in germinating sorghum seeds always increases at stage II (emergence of the radicle), is maintained during the aerobic period of rapid cell division and reserve mobilization, and remains relatively constant until stage IV-V when coleoptiles initiate the formation of the photosynthetic tissues.

The Effect of Bacteria on Seed Germination in Sorghum and Rape Under Cadmium and Petroleum Conditions

A large amount of oil hydrocarbons and heavy metals have been discharged into the environment and caused soil polluted. Petroleum and cadmium in soil accumulated in crops and lead to threaten human healthy through the food chain. In this experiment, seeds of sorghum and rape were germinated in deferent concentrations of petroleum and cadmium, and the effect of Peptococcus activus sp. SH3-3-9 on the germination was studied. The results showed that petroleum and cadmium inhibited seeds germination, and the effects were stronger as their concentrations increased. Peptococcus activus sp.SH3-3-9 had the role of enhancing seed germination, which indicates it has high potential in plant-microbial remediation of petroleum and cadmium in soil.

Soil Properties Under Manured Tamarindus indica in the Littoral Plain of South-Western Madagascar

The current study investigated how the presence of tamarinds and manure affect (1) soil chemical properties; (2) C and N mineralization; (3) microbial biomass indices (C, N, and fungal ergosterol); (4) microbial residues, that is, amino sugars; and (5) the germination of sorghum seeds in soils of the littoral zone in southwestern Madagascar. Soil pH was lower under than outside the tamarind canopy, whereas SOC, total N content, and the cation exchange capacity were roughly three times higher than in the uncovered situation. Under the tamarind canopy, basal respiration was increased nearly threefold, whereas net N mineralization remained unaffected. However, net N mineralization was increased by 74% in the manure treatment, especially under the tamarind canopy. Tamarind did not inhibit the germination of sorghum seeds. Contents of microbial biomass C and N, and especially fungal ergosterol, were also higher under the tamarind canopy. Muramic acid, galactosamine, and glucosamine were increased threefold under the tamarind canopy. The mean fungal C to bacterial C ratio was 0.67 and remained unaffected by any treatment. The presence of manure increased the contribution of microbial residue C to SOC from 28% to 41% and of microbial biomass N to total N from 3.5% to 5.6%, especially under the tamarind canopy.

In vivomonoubiquitination of anaplerotic phosphoenolpyruvate carboxylase occurs at Lys624 in germinating sorghum seeds

Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) is an important cytosolic regulatory enzyme that plays a pivotal role in numerous physiological processes in plants, including seed development and germination. Previous studies demonstrated the occurrence of immunoreactive PEPC polypeptides of ~110kDa and 107kDa (p110 and p107, respectively) on immunoblots of clarified extracts of germinating sorghum (Sorghum bicolor) seeds. In order to establish the biochemical basis for this observation, a 460kDa PEPC heterotetramer composed of an equivalent ratio of p110 and p107 subunits was purified to near homogeneity from the germinated seeds. Mass spectrometry established that p110 and p107 are both encoded by the same plant-type PEPC gene (CP21), but that p107 was in vivo monoubiquitinated at Lys624 to form p110. This residue is absolutely conserved in vascular plant PEPCs and is proximal to a PEP-binding/catalytic domain. Anti-ubiquitin IgG immunodetected p110 but not p107, whereas incubation with a deubiquitinating enzyme (USP-2 core) efficiently converted p110 into p107, while relieving the enzyme’s feedback inhibition by l-malate. Partial PEPC monoubiquitination was also detected during sorghum seed development. It is apparent that monoubiquitination at Lys624 is opposed to phosphorylation at Ser7 in terms of regulating the catalytic activity of sorghum seed PEPC. PEPC monoubiquitination is hypothesized to fine-tune anaplerotic carbon flux according to the cell’s immediate physiological requirements for tricarboxylic acid cycle intermediates needed in support of biosynthesis and carbon–nitrogen interactions.

English

Phosphatases are widely found in plants having intracellular and extracellular activities. Phosphatases are believed to be important for phosphorous scavenging and remobilization in plants, but its role in adaptation to abiotic stresses and growth hormones at germination level has not been critically evaluated. To address this issue, the effect of ABA, GA3, NaCl and drought on germination, growth, acid and alkaline phosphatases in sorghum embryos and endosperm was investigated. Germination decreased markedly under ABA, NaCl and drought treatments. Subsequently, a remarkable decrease in fresh weight and dry weight was observed in embryos under ABA and NaCl treatments, whereas a significant decrease in endosperm fresh weight was observed only under drought stress. However, no significant change in endosperm dry weight was observed under other any treatment. Furthermore, a considerable increase in acid phosphatse activity was observed in embryos under GA3 and NaCl treatments, however, alkaline phosphatase activity was substantially higher under all treatments. In endosperm, a significant increase in acid phosphatase activity was observed under ABA and NaCl treatments. Alkaline phosphatse activity was apparently higher under GA3. However, no substantial changes in acid or alkaline phosphatase activities were observed after drought treatments. These findings suggest that changes in the phosphatase enzymes might play important roles in adaptation of germinating seeds, to changing environmental conditions.  Based upon these results, a possible physiological role of phosphatases in germinating sorghum seeds is discussed.   Keywords: Growth, sorghum, acid phosphatase, alkaline phosphatase.

Changes in germination, growth and soluble sugar contents of Sorghum bicolor (L.) Moench seeds under various abiotic stresses

The effect of various abiotic stresses on germination rate, growth and soluble sugar content in Sorghum bicolor (L.) Moench cv. CSH 6 seed embryos and endosperm during early germination was investigated. Under stress conditions germination, water potential and tissue water content decreased markedly. Subsequently, this reduction resulted in marked decreases in fresh weight both in embryos and endosperm. Conversely, a substantial increase in dry weight was observed. Furthermore, a considerable increase in the sugar contents in both embryo and endosperm was detected. The fructose level was always higher than glucose and sucrose in response to various stresses. However, as compared to the control the level of glucose and sucrose was higher in embryos and endosperm after stress treatments. Based upon these results a possible physiological role of sugars in the germination of sorghum seeds is discussed.

Managing Parkia biglobosa and Vitellaria paradoxa Prunings for Crop Production and Improved Soil Properties in the Sub-Sudanian Zone of Burkina Faso

Tree pruning generates organic resources whose nitrogen content is not always recycled appropriately. A field experiment was conducted in the central plateau of Burkina Faso to test the possibilities of improving soil properties and crop production through the application of Parkia biglobosa (néré) and Vitellaria paradoxa (karité) prunings as mulch. Two rates of leaf material of each species were applied and compared with a control (without mulch). Each treatment was repeated four times. Positions from the trees (around the trunk, eastern side, western side and outside the crown) were considered as blocks in a randomized blocks design. The physical and chemical properties of soil were measured during the second year whereas millet production was assessed over two cropping seasons. Two laboratory experiments were conducted with leachates of the leaves of each species to test the possible inhibition of crop germination or growth. The results of the field experiment showed a depressing effect of the mulch of Parkia biglobosa by 33% for millet grain yield and by 21% for total dry matter. However, Vitellaria paradoxa mulch increased grain yield by 120% and total dry matter by 43%. Ponding time and total C content were higher on plots that received the highest amount of leaves of both species. In the laboratory experiments, germination of sorghum seeds treated with leachate of 50 g of the leaves of Vitellaria paradoxa in 250 mL distilled water was reduced by 37% whereas the reduction was only 19% for the leachate of the leaves of Parkia biglobosa. It was concluded that, at least in the short term, millet production could be improved through the application of Vitellaria paradoxa mulch.

Posttranslational regulation of phosphoenolpyruvate carboxylase during germination of Sorghum seeds: influence of NaCl and l-malate

Phosphoenolpyruvate carboxylase (EC 4.1.1.31: PEPC) was characterized in de-embryonated Sorghum seeds, focusing on the interaction between metabolites and posttranslational control of the enzyme by phosphorylation. Two PEPC polypeptides (108 and 110 kDa) were resolved by SDS/PAGE and shown to increase, in parallel with PEPC activity during seed germination. PEPC displayed very low K m values for PEP (90 μM) and inhibition constant (IC 50) for l-malate (75 μM) in desalted protein extracts from de-embryonated dry seeds. The inhibition of PEPC by 0.16 mM l-malate, pH 7.3, decreased from 70 to 30%, along with a consistent increase in IC 50 (75–220 μM) after 5 days of germination. PEPC phosphorylation was established both in vivo, after imbibing the seeds with [ 32P]phosphate, and in vitro in reconstituted assays. A PEPC kinase (PEPCk) was partially purified from seed protein extracts by blue dextran agarose chromatography and shown to be independent of calcium and to phosphorylate both seed and recombinant C 4 PEPC from Sorghum on the enzyme’s N-terminal domain. Seed germination, PEPC accumulation and phosphorylation were severely inhibited in the presence of NaCl in the imbibing medium, although PEPCk content was not altered. However, in vitro, NaCl had no effect on both PEPCk activity and PEPC phosphorylation. On the other hand, l-malate was a potent inhibitor of seed PEPCk activity in in vitro assays. Since NaCl also decreased the rate of l-malate consumption in the imbibing grain, the salt inhibition of PEPC phosphorylation was suggested to be due to the concentration-dependent blocking of PEPCk activity in vivo by this compound. Consistent with these data, germination and PEPC phosphorylation were inhibited, while PEPCk levels were not altered, when seeds were germinated in the presence of l-malate.

Phytotoxicity of fatty acids present in dairy and hog manure

Abstract The application of animal waste on farm land is currently considered as a safe method to dispose the excreta from farm animals because it provides an easy outlet to alleviate envaronmental danger associated with animal excreta. In most published studies, animal waste is viewed as a good source of nitrogen, phosphorus and potassium (NPK). Little attention has been given to minor chemical compounds present in the contents of animal wastes. Some classes of compounds which are suspected to be phytotoxic have been reported to be present in animal waste. Identification and mode of action of such compounds present in animal waste is important because agricultural practices which are considered as environmentally safe today may become a hazard to agricultural crops in the future. Fatty acids are known for germination inhibiting activity. The objectives of this study were to identify fatty acids present in dairy and hog manures and to investigate their biological effects on germination of sorghum seeds. S...

HEAT SENSITIVITY, OPTIMUM pH AND CHANGES IN ACTIVITY OF SORGHUM PEROXIDASE DURING MALTING AND MASHING

Peroxidase activity was demonstrated in dry and germinating sorghum seeds. The specific activity increased about 14-fold during malting for a 96-hour period. On the average about 41% of peroxidase activity was located in the endosperm, and the remaining 56% in the acrospire and rootlet of sorghum malt. The crude enzyme extract retained 77%, 17.5% and 7.6% of activity after heating at 60°, 70° and 80°C, respectively. More than 50% of the peroxidase activity in the finished malt survived mashing at 65°C. Optimum activity was recorded at pH 5.5 which falls within the observed pH range of sorghum worts. The level of residual peroxidase activity in the wort differed with sorghum species.

Physiological Basis of Salinity Tolerance of Sorghum Seeds During Germination

AbstractEffects of salinity on the isozyme activities of α‐amylase in germinating sorghum seeds were studied under laboratory conditions. Seeds were imbibed in NaCl solutions at concentrations ranging from 0–500 nM (osmotic pressure: 0–2.28 MPa) for 0–24 h and the isozymes activities were estimated after disc‐gel electrophoresis.Seed germination of sorghum was not affected by NaCl concentrations less than 100 nM (0.46 MPa). Germination was reduced by 50% at 300 nM NaCl (1.31 MPa), and completely inhibited at 500 nM (2.28 MPa). The α‐amylase activity in the treated seeds followed a similar pattern to that of germination.At least five isozyme patterns of a‐amylase were observed in germinating sorghum seeds. The activities of the respective isozymes were enhanced with increasing duration of imbibition in distilled water. When treated with 100 nM NaCl, the activities of isozymes 2 and 5 decreased, but this was compensated by the increased activity of isozyme 1. The sensitivity of isozymes to the salinity treatments varied where isozyme 1 was the most tolerant. The isozyme activities were completely inhibited by 500 nM NaCl.The results indicate that sorghum seeds could germinate well in saline environments up to 0.46 MPa. Higher osmotic pressure or saline concentrations could be detrimental to the seed germination of sorghum. The salinity tolerance could be attributable to the compensation of loss of activities of certain isozymes of α‐amylase by the other types.

Identification and Biological Activity of Germination-Inhibiting Long-Chain Fatty Acids in Animal-Waste Composts

Long-chain fatty acids in germination-inhibiting animal-waste composts were identified by gas chromatography-mass spectrometry as myristic, palmitic, stearic, oleic, linoleic, and linolenic acids. These acids were found at concentrations greater than 0.25 mg (g dry compost)-1. The identified acids, together with lauric acid, and five kinds of short- and medium-chain fatty acid, were tested for their effects on the germination process of sorghum seeds. The authentic long-chain fatty acids, which were dissolved in a 1:9 (v/v) mixture of methanol and distilled water at 40 mg liter-1, significantly reduced the alpha-amylase activity, physiological water uptake, and ATP content of the germinating seeds during the first 24 h of inhibition, as well as the rate of germination of seeds. Among the tested fatty acids, myristic and palmitic acids were the most potent inhibitors of germination. The inhibitory effects of long-chain fatty acids were stronger than those of the phenolic acids. The short- and medium-chain fatty acids did not have any significant germination-inhibitory effects at 40 mg liter-1. The results indicate that the long-chain fatty acids are the dominant inhibitors of germination in animal-waste composts, and that the inhibition of the alpha-amylase activity in germinating sorghum seeds is one aspect of the mode of action of these long-chain fatty acids.

Effect of inorganic cations in animal-waste composts on water and cation absorption of germinating sorghum (sorghum bicolorL. Moench) seeds

Abstract The effects of soluble inorganic cations contained in some animal-waste composts on water and cation absorption and subsequent germination of sorghum (Sorghum hicolor L. Moench) seeds were investigated under laboratory conditions. The cation content of the seeds imbibed in the compost extracts showed a positive linear correlation with the water soluble cation concentration in the respective compost extracts. Water absorption of compost-imbibed sorghum seeds was well correlated with subsequent germination. However, the Na+ and K+ contents in imbibed seeds and the total soluble cation content in compost extracts did not contribute significantly to seed water absorption. Thus, it was suggested that the cation concentration in the compost medium and the cation influx during seed imbibition have a lesser impact on the control of water absorption via osmotic adjustment and subsequent germination of sorghum seeds. Some possible factors that may influence water absorption of sorghum seeds imbibed in anim...

Allelopathic influence ofSorghum bicolor on weeds during germination and early development of seedlings

The allelopathic interaction between sorghum [Sorghum bicolor (L.) Moench] and 10 species of grass and broadleaf weeds was investigated. Germination of weed seeds was slightly inhibited or stimulated, depending on species, when incubated in closed Petri dishes with germinating sorghum. Subsequent radicle and hypocotyl or coleoptile elongation of weeds was significantly inhibited by the germinating sorghum. For weeds interplanted with sorghum and grown under greenhouse conditions. The inhibitory effect on some weed species was still evident after 2 months of growth. Significant differences were found in the dry matter per weed plant grown in pots in proximity to sorghum vs. weeds grown in monoculture. Aqueous leachates from pots planted with sorghum alone or from a system in which sorghum roots protruded into water had strong allelopathic activity. These results indicate that water-soluble allelochemicals are produced by germinating sorghum seeds and that production of these substances continues during seedling growth.

Long‐Term Preservation of Sorghum Seed as Affected by Seed Moisture, Temperature, and Atmospheric Environment

Longevity of stored seed is affected by a number of controllable environmental factors. Sorghum bicolor (L.) Moench. seeds were stored in sealed metal cans to test the effects and interactions of three moisture levels, six atmospheric conditions, and five temperature regimes over a 16‐year period. Vacuum, and atmospheres of air, nitrogen, carbon dioxide, helium, and argon were not significantly different in preserving seed germination. Sealed samples maintained better germination than samples in paper envelopes at temperatures above freezing. At –1 C and –12 C, all treatments maintained good germination. Temperatures of 10, 21, and 32 C interacted with seed moistures of 4, 7, and 10%. At 32 C and 10% seed moisture all seeds were dead in 8 years. Germination of sorghum seeds was best preserved at –12 C, regardless of seed moisture content, atmospheric environment, or storage medium during the 16 years of storage.