Respiration of soybean plants in relation to their physiological conditions. III. The characteristics of respiration in leaves and roots under attached and detached conditions.

Excessive plant height is an important factor that can lead to lodging, which is closely related to soybean yield. Gibberellins are widely used as plant growth regulators in agricultural production. Gibberellic acid (GA3), one of the most effective active gibberellins, has been used to regulate plant height and increase yields. The mechanism through which GA3 regulates internode elongation has been extensively investigated. In 2019 and 2020, we applied GA3 to the stems, leaves, and roots of two soybean cultivars, Heinong 48 (a high-stalk cultivar) and Henong 60 (a dwarf cultivar), and GA3 was also applied to plants whose apical meristem was removed or to girded plants to compare the internode length and stem GA3 content of soybean plants under different treatments. These results suggested that the application of GA3 to the stems, leaves, and roots of soybean increased the internode length and GA3 content in the stems. Application of GA3 decreased the proportion of the pith in the soybean stems and primary xylem while increasing the proportion of secondary xylem. The apical meristem is an important site of GA3 synthesis in soybean stems and is involved in the regulation of stem elongation. GA3 was shown to be transported acropetally through the xylem and laterally between the xylem and phloem in soybean stems. We conclude that the GA3 level in stems is an important factor affecting internode elongation.

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Comparative Metabolome Profile between Tobacco and Soybean Grown under Water-Stressed Conditions

BioMed Research International ◽

10.1155/2017/3065251 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 21

Author(s):

Roel C. Rabara ◽

Prateek Tripathi ◽

Paul J. Rushton

Keyword(s):

Water Deficit ◽

Stomatal Closure ◽

Specific Accumulation ◽

Leaf Tissues ◽

Soybean Roots ◽

Species Responses ◽

Leaves And Roots ◽

Soybean Plants ◽

Tobacco Roots ◽

Soybean Leaves

Understanding how plants respond to water deficit is important in order to develop crops tolerant to drought. In this study, we compare two large metabolomics datasets where we employed a nontargeted metabolomics approach to elucidate metabolic pathways perturbed by progressive dehydration in tobacco and soybean plants. The two datasets were created using the same strategy to create water deficit conditions and an identical metabolomics pipeline. Comparisons between the two datasets therefore reveal common responses between the two species, responses specific to one of the species, responses that occur in both root and leaf tissues, and responses that are specific to one tissue. Stomatal closure is the immediate response of the plant and this did not coincide with accumulation of abscisic acid. A total of 116 and 140 metabolites were observed in tobacco leaves and roots, respectively, while 241 and 207 were observed in soybean leaves and roots, respectively. Accumulation of metabolites is significantly correlated with the extent of dehydration in both species. Among the metabolites that show increases that are restricted to just one plant, 4-hydroxy-2-oxoglutaric acid (KHG) in tobacco roots and coumestrol in soybean roots show the highest tissue-specific accumulation. The comparisons of these two large nontargeted metabolomics datasets provide novel information and suggest that KHG will be a useful marker for drought stress for some members of Solanaceae and coumestrol for some legume species.

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Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050986 ◽

1974 ◽

Vol 32 ◽

pp. 194-195

Author(s):

Å. Thureson-Klein

Keyword(s):

Schwann Cells ◽

Cell Organelles ◽

Giant Mitochondria ◽

Matrix Density ◽

Physiological Conditions ◽

Unmyelinated Axons ◽

Internal Structures ◽

Structural Abnormalities ◽

Cytotoxic Compounds ◽

Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

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Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157991 ◽

1990 ◽

Vol 48 (3) ◽

pp. 90-91

Author(s):

N. Seki ◽

Y. Toyama ◽

T. Nagano

Keyword(s):

Plasma Membrane ◽

Essential Role ◽

Freeze Fracture ◽

Final Concentration ◽

Freeze Fracturing ◽

Physiological Conditions ◽

Epididymal Maturation ◽

Cacodylate Buffer ◽

Sperm Membrane ◽

Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

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