Factors Controlling Endosperm Cell Number and Grain Dry Weight in Wheat: Effects of Shading on Intact Plants and of Variation in Nutritional Supply to Detached, Cultured Ears

1984 ◽  
Vol 11 (3) ◽  
pp. 151 ◽  
Author(s):  
BK Singh ◽  
CF Jenner
Keyword(s):  
Cell Division ◽  
External Medium ◽  
Amino Nitrogen ◽  
Dry Weight ◽  
Cell Number ◽  
Soluble Carbohydrates ◽  
Endosperm Cell ◽  
Intact Plants ◽  
Organic Nutrients ◽  
Photon Exposure

The association between endosperm cell number and grain dry weight, and the dependence of endosperm cell division on the availability of organic nutrients, have been investigated in wheat. Two different procedures were used to vary the supply of nutrients to the grains during the phase of cell division. Detached ears were cultured in solutions of sucrose (0-60 g 1-1) and glutamine (0.125-0.75 g N 1-1), or intact plants were exposed to high (560 �mol m-2 s-1) or low (55 �mol m-2 s-1) photon irradiance. Cell number per endosperm, and grain dry weight, were both responsive to the concentration of nutrients in the external medium, and to the level of photon exposure. Average dry weight per cell was relatively independent of the level of nutrition or of photon exposure until cell division had ceased but, in the later stages of grain-filling, dry weight per cell in the cultured ears displayed a dependence upon the concentration of nutrients in the external medium. Amounts of sucrose, other soluble carbohydrates and soluble amino nitrogen were extracted from the grains and, on a per grain basis, the amounts of all fractions varied in response to variation in the level of nutrients supplied to the ears, and to photon exposure. However, concentrations of these nutrients in the developing grains, calculated on a dry weight or water basis, were not associated with the rate of cell division in the grains. While the evidence gathered supports the notion that growth (in cell number, and dry weight) of the developing endosperm is controlled inter alia by the provision of organic nutrients, the nature of the controlling mechanism is obscure. It seems that cellular division is not affected directly by nutritional supply through a mechanism involving the concentration of substrates for energy and protein synthesis within the developing grain.

Association Between Concentration of Organic Nutrients in the Grain, Endosperm Cell Number and Grain Dry Weight Within the Ear of Wheat

1982 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
BK Singh ◽  
CF Jenner
Keyword(s):  
Amino Acids ◽  
Inverse Relationship ◽  
Dry Weight ◽  
Cell Number ◽  
Grain Weight ◽  
Endosperm Cell ◽  
Cell Numbers ◽  
Carbohydrate Concentration ◽  
Organic Nutrients ◽  
Number Of Cells

The present investigation was conducted to examine the association between the concentrations of sugars and amino acids in the grain, cell number in the endosperm and final dry weights of grains at various positions within the ear of wheat. Variation in the grain weight within a spikelet or between spikelets was dependent upon the number of cells formed in the endosperm. Concentrations of assimilates measured in the grain, however, showed either no relationship or an inverse relationship with the endosperm cell numbers. Variation in cell number in the endosperm between spikelets inserted at different positions on the rachis was not related to the carbohydrate concentration in the sections of rachis bearing the respective spikelets.

Some morphological, anatomical, and physiological changes in the pear fruit (Pyrus communis var. Williams Bon Chrétien) during development and following harvest

1961 ◽  
Vol 9 (2) ◽  
pp. 99 ◽  
Author(s):  
JM Bain
Keyword(s):  
Cell Division ◽  
Morphological Changes ◽  
Complex Structure ◽  
Titratable Acidity ◽  
Dry Weight ◽  
Cell Number ◽  
Pyrus Communis ◽  
Physiological Changes ◽  
Pear Fruit ◽  
Protein Nitrogen

Morphological, anatomical, and physiological changes occurring in the developing fruit of Pyrus communis var. Williams Bon Chretien were studied at frequent intervals, from blossom until after commercial maturity, in three successive seasons. Morphological changes were shown by increase in measurements of volume, long and short axis, and the width of the cortex (flesh), the morphology of the fruit being interpreted by the receptacular theory, Anatomical changes were given by the duration and distribution of cell division, differentiation of tissues, cell size, and cell number. Physiological changes were expressed as changes in fresh weight, dry weight, and moisture content for the whole fruit, and separately for the flesh, peel, and core in the second and third seasons. Total and reducing sugars, starch, titratable acidity, and total and protein nitrogen were estimated per gram of dried flesh at each sampling. Respiration rates for whole fruit were measured by the Pettenkofer method. Physiological changes could not be expressed on a per cell basis because of the complex structure of pear tissue. Data presented on the basis of the number of days from blossom showed two distinct stages in fruit growth. Stage I, the first 42-56 days of development, corresponded to the main cell division period and was characterized by more rapid morphological but slower physiological changes (except for increase in protein nitrogen) than Stage 11, the remainder of the time on the tree. Comparable trends were found in the three seasons, but drought reduced growth rate in the first season. Some ripening changes were followed on removal from the tree and after periods of cold storage at 0°C.

Morphological development of rice caryopses located at the different positions in a panicle from early to middle stage of grain filling

2003 ◽  
Vol 30 (11) ◽  
pp. 1139 ◽  
Author(s):  
Tsutomu Ishimaru ◽  
Toshiaki Matsuda ◽  
Ryu Ohsugi ◽  
Tohru Yamagishi
Keyword(s):  
Cell Division ◽  
Grain Filling ◽  
Cell Number ◽  
Morphological Development ◽  
Endosperm Cell ◽  
Coordinated Development ◽  
Storage Tissue ◽  
Middle Stage

Rice caryopses show different patterns of grain filling depending on position within a panicle. Caryopses located on the upper primary rachis branches generally accumulate larger amounts of starch at maturity than caryopses located on the secondary rachis branches of the lower primary rachis. In this study, the former and latter types of caryopses were defined as superior and inferior caryopses, respectively. Superior caryopses elongated soon after flowering, whereas inferior caryopses hardly elongated and were morphologically stagnant until the first 4 d after flowering (DAF). However, once inferior caryopses began elongation, their morphological development was the same as superior caryopses until the middle stage of grain filling. Cell division of the inner integument ceased before endosperm cellularization, pericarp functioned as a transient starch storage tissue until endosperm accumulated starch, and endosperm cell number was determined concomitantly with nucellus disintegration. These results implied the coordinated development of the endosperm with maternal tissues. In addition, differences of inner-integument cell number and endosperm cell number were related to a difference of endosperm size between superior and inferior caryopses.

Cadmium toxicity on synchronous populations of Chlorella ellipsoidea

1980 ◽  
Vol 58 (16) ◽  
pp. 1780-1788 ◽  
Author(s):  
H. Lue-Kim ◽  
P. C. Wozniak ◽  
R. A. Fletcher
Keyword(s):  
Cell Division ◽  
Toxic Effect ◽  
Cadmium Toxicity ◽  
Chlorophyll Concentration ◽  
Membrane Integrity ◽  
Dry Weight ◽  
Cell Number ◽  
Dark Phase ◽  
Chlorella Ellipsoidea ◽  
Synchronous Cultures

The primary phycotoxic effects of various concentrations (5–50 μM) of cadmium sulfate (CdSO4) on synchronous cultures of Chlorella ellipsoidea were determined during a 14-h light and a 10-h dark incubation cycle. At a concentration of 5 μM CdSO4 there was a slight stimulation in cell number, chlorophyll level, and dry weight whereas at higher concentrations (10–40 μM) a linear decrease in these parameters was evident. At even higher concentrations, 50 μM and above, cytolysis occurred. Inhibition of chlorophyll concentration and dry weight was greater the longer the cultures were exposed to cadmium. Cell division was completely arrested when toxic levels of cadmium were administered any time throughout the duration of the light phase. However, the severity of toxicity of cadmium, when applied during the dark phase, increased with the length of time of exposure. Cadmium toxicity also resulted in disturbances in cell division. Treated cells became larger than control cells. Unequal sporulation, microcolony and incipient microcolony formation, swelling, increased photolucence, and disruption of mitochondria occurred following treatment of cultures with toxic levels of cadmium. A further toxic effect of cadmium might relate to an increase in membrane permeability. Treatment of cultures with increasing concentrations of cadmium resulted in intracellular cadmium exceeding extracellular cadmium levels. The primary toxic effect of cadmium on synchronous cultures of C. ellipsoidea was attributed to a lack of cell division probably related to insufficient synthesis of chlorophyll and dry weight components as well as to a disruption of membrane integrity.

Herbicidal potential of Aerva javanica to control wild oat in wheat crop

2020 ◽  
Vol 51 (2) ◽  
pp. 177-194
Author(s):  
Al-Ghamdi A.M. ◽  
El-Zohri M
Keyword(s):  
Dry Weight ◽  
Soluble Carbohydrates ◽  
Wheat Crop ◽  
Aqueous Extracts ◽  
Wild Oat ◽  
Culture Experiment ◽  
Allelopathic Potential ◽  
Root Extracts ◽  
Wheat Germination ◽  
Radical Length

We investigated the phytotoxicity of desert cotton (Aerva javanica) extracts on wild oat and wheat. Aqueous extracts from A. javanica roots, leaves and inflorescences collected from Jeddah and Al-Baha regions, Saudi Arabia were used. Generally, the allelopathic potential of water extracts of A. javanica collected from Jeddah were more in inhibitory to wild oat germination and seedlings growth than those from Al-Baha. In both regions, root extracts were inhibitory to wild oat followed by leaves and inflorescences extracts. All test aqueous extracts of both regions did not inhibit the wheat germination or seedlings growth.Whreas, the wild oat germination was reduced by root extracts 58.62 %, 28.62 % leaves extracts : 32.72 %, 17.72 % and inflorescences extract 28.11 %, 12.13 % by in plants samples collected from Jeddah and Al-Baha, respectively. Wild oat radical length was inhibited by root extracts 53.27 %, 32.84 % leaves 42.35 %, 9.63 % and inflorescences extracts 22.64 %, 16.75 % in case of Jeddah and Al-Baha plants, respectively. In pot culture experiment, all treatments markedly reduced the plant dry weight and soluble carbohydrates, proteins and free amino acids contents in wild oat. The differences in the allelopathic potentials of studied A. javanica extracts were related to the qualitative variations in their phytochemicals constituents. Our results showed that A. javanica extracts could be safely used to control wild oat growth in wheat fields after more detsaled research..

scholarly journals Sound Waves Promote Arabidopsis thaliana Root Growth by Regulating Root Phytohormone Content

2021 ◽  
Vol 22 (11) ◽  
pp. 5739
Author(s):  
Joo Yeol Kim ◽  
Hyo-Jun Lee ◽  
Jin A Kim ◽  
Mi-Jeong Jeong
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Division ◽  
Root Growth ◽  
Apical Meristem ◽  
Cell Number ◽  
Root Apical Meristem ◽  
Control Group ◽  
Auxin Signaling ◽  
Ethylene Signaling ◽  
Sound Waves

Sound waves affect plants at the biochemical, physical, and genetic levels. However, the mechanisms by which plants respond to sound waves are largely unknown. Therefore, the aim of this study was to examine the effect of sound waves on Arabidopsis thaliana growth. The results of the study showed that Arabidopsis seeds exposed to sound waves (100 and 100 + 9k Hz) for 15 h per day for 3 day had significantly longer root growth than that in the control group. The root length and cell number in the root apical meristem were significantly affected by sound waves. Furthermore, genes involved in cell division were upregulated in seedlings exposed to sound waves. Root development was affected by the concentration and activity of some phytohormones, including cytokinin and auxin. Analysis of the expression levels of genes regulating cytokinin and auxin biosynthesis and signaling showed that cytokinin and ethylene signaling genes were downregulated, while auxin signaling and biosynthesis genes were upregulated in Arabidopsis exposed to sound waves. Additionally, the cytokinin and auxin concentrations of the roots of Arabidopsis plants increased and decreased, respectively, after exposure to sound waves. Our findings suggest that sound waves are potential agricultural tools for improving crop growth performance.

scholarly journals Arsenic Application Changed Growth, Photo-Synthetic Pigments and Antioxidant Enzymes Activity in Sorghum (Sorghum bicolor L.) Under Salinity Stress

2019 ◽  
Vol 50 (3) ◽  
pp. 155-163 ◽  
Author(s):  
B. Talebi ◽  
M. Heidari ◽  
H. Ghorbani
Keyword(s):  
Plant Biomass ◽  
Dry Weight ◽  
Carotenoid Content ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Guaiacol Peroxidase ◽  
Anthocyanin Content ◽  
Synthetic Pigments ◽  
Root Tissues ◽  
Gpx Activity

Abstract The elevation of arsenic (As) content in soils is of considerable concern with respect to its uptake by plant and subsequent entry into wildlife and human food chains. The treatment of sorghum seedlings with As as NaH2As4O. 7H2O at various concentrations (A1 = 0, A2 = 20, A3 = 40 and A4 = 60 mg As kg−1 soil) and salinity at four different levels (S1 = 0, S2 = 3, S3 = 6 and S3 = 9 dS m−1) reduced fresh and dry weights of sorghum plants. The co-application of As and salinity increased the guaiacol peroxidase (GPX) activity in shoot and root tissues. The highest GPX activity in shoot and root tissues was obtained at S2A4 and S3A3 treatments, respectively. The activity of catalase (CAT) in shoot was not changed, but unlike the GPX activity, salinity and As decreased the CAT activity in root tissues. Concerning the photosynthesis pigments, salinity had no effect on the chlorophyll ‘a’, chlorophyll ‘b’ and carotenoid content in leaves, but the As treatment significantly decreased the content of both chlorophyll types. Salinity increased the anthocyanin content in leaves. There were negative correlation between soluble carbohydrates (r2 = −0.78**) and stomata conductance (r2 = −0.45**) and dry weight of the plant biomass in this study. By increasing the salinity and As concentration in root medium, soluble carbohydrate in leaves increased but salinity decreased the leaf stomata conductance.

scholarly journals Rootstock Effects on Growth, Cell Number, and Cell Size of `Gala' Apples

2004 ◽  
Vol 129 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Yahya K. Al-Hinai ◽  
Teryl R. Roper
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Agricultural Research ◽  
Fruit Size ◽  
Cell Number ◽  
Fruit Growth ◽  
Research Station ◽  
Full Bloom ◽  
Final Size ◽  
Load Effects

The effects of rootstock on growth of fruit cell number and size of `Gala' apple trees (Malus domestica Borkh) were investigated over three consecutive seasons (2000-02) growing on Malling 26 (M.26), Ottawa-3, Pajam-1, and Vineland (V)-605 rootstocks at the Peninsular Agricultural Research Station near Sturgeon Bay, WI. Fruit growth as a function of cell division and expansion was monitored from full bloom until harvest using scanning electron microscopy (SEM). Cell count and cell size measurements showed that rootstock had no affect on fruit growth and final size even when crop load effects were removed. Cell division ceased about 5 to 6 weeks after full bloom (WAFB) followed by cell expansion. Fruit size was positively correlated (r2 = 0.85) with cell size, suggesting that differences in fruit size were primarily a result of changes in cell size rather than cell number or intercellular space (IS).

Effect of Cytokinins on the Expansion and Metabolism of Excised Cucumber Cotyledons

1980 ◽  
Vol 7 (3) ◽  
pp. 227
Author(s):  
C Tsui ◽  
Tao Guo-qing ◽  
Chen Hui-ying ◽  
Son Yan-ru ◽  
Lian Han-ping ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Acid Synthesis ◽  
Cell Number ◽  
Cucumis Sativus L ◽  
Biochemical Processes ◽  
Dna And Rna ◽  
Lag Period ◽  
Hydrolysis Of

Expansion of excised cucumber (Cucumis sativus L.) cotyledons was stimulated by treatment with cytokinin, and commenced after a lag period of about 4 h. Expansion induced by benzyladenine (BA) was due mainly to increase of fresh weight, but cell number increased slightly. Hydrolysis of protein and lipid was stimulated by BA, and soluble sugars increased simultaneously. However, there was no significant change in the dry weight of cotyledons during the period of expansion. It is assumed that the transformation of lipid to sugar in the cotyledon is stimulated by BA. The respiration of cotyledons was evidently stimulated by BA and was entirely inhibited by respiratory inhibitors, e.g. NaN,, malonate and dinitrophenol. Inhibitors of protein and nucleic acid synthesis, such as chloramphenicol and actinomycin D, inhibited only the BA-induced expansion. They had no effect on the expansion of controls. These results suggest that different biochemical processes are involved in the expansion of cotyledons induced by BA and in controls. The former is related not only to respiration but also to the synthesis of protein and nucleic acid. BA increased DNA and RNA content per cotyledon. The increase of total RNA is due mainly to the increase of 25 S and 18 S rRNA.

scholarly journals New Insights into Methyl Bromide Cooxidation byNitrosomonas europaea Obtained by Experimenting with Moderately Low Density Cell Suspensions

2000 ◽  
Vol 66 (7) ◽  
pp. 2726-2731 ◽  
Author(s):  
Khrystyne N. Duddleston ◽  
Peter J. Bottomley ◽  
Angela J. Porter ◽  
Daniel J. Arp
Keyword(s):  
Cell Division ◽  
Methyl Bromide ◽  
Cell Activity ◽  
Dry Weight ◽  
Cell Suspensions ◽  
Low Density ◽  
Level Of Activity ◽  
End Products ◽  
Uptake Activity ◽  
Fresh Growth Medium

ABSTRACT We examined the rates and sustainability of methyl bromide (MeBr) oxidation in moderately low density cell suspensions (∼6 � 107 cells ml−1) of the NH3-oxidizing bacterium Nitrosomonas europaea. In the presence of 10 mM NH4 + and 0.44, 0.22, and 0.11 mM MeBr, the initial rates of MeBr oxidation were sustained for 12, 12, and 24 h, respectively, despite the fact that only 10% of the NH4 +, 18% of the NH4 +, and 35% of the NH4 +, respectively, were consumed. Although the duration of active MeBr oxidation generally decreased as the MeBr concentration increased, similar amounts of MeBr were oxidized with a large number of the NH4 +-MeBr combinations examined (10 to 20 μmol mg [dry weight] of cells−1). Approximately 90% of the NH3-dependent O2uptake activity and the NO2 −-producing activity were lost after N. europaea was exposed to 0.44 mM MeBr for 24 h. After MeBr was removed and the cells were resuspended in fresh growth medium, NO2 −production increased exponentially, and 48 to 60 h was required to reach the level of activity observed initially in control cells that were not exposed to MeBr. It is not clear what percentage of the cells were capable of cell division after MeBr oxidation because NO2 − accumulated more slowly in the exposed cells than in the unexposed cells despite the fact that the latter were diluted 10-fold to create inocula which exhibited equal initial activities. The decreases in NO2 −-producing and MeBr-oxidizing activities could not be attributed directly to NH4 + or NH3 limitation, to a decrease in the pH, to the composition of the incubation medium, or to toxic effects caused by accumulation of the end products of oxidation (NO2 − and formaldehyde) in the medium. Additional cooxidation-related studies of N. europaea are needed to identify the mechanism(s) responsible for the MeBr-induced loss of cell activity and/or viability, to determine what percentages of cells damaged by cooxidative activities are culturable, and to determine if cooxidative activity interferes with the regulation of NH3-oxidizing activity.

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