scholarly journals Diffusion of Carbon Compounds Away from Wheat Roots

1969 ◽  
Vol 22 (5) ◽  
pp. 1287 ◽  
Author(s):  
AD Rovira
Keyword(s):  
Broad Bean ◽  
French Bean ◽  
Water Soluble ◽  
Root Tip ◽  
Apical Region ◽  
Basal Region ◽  
Wheat Roots ◽  
Root Zones ◽  
Carbon Compounds ◽  
Intact Roots

The exudation of organic compounds from intact roots has been reported for many plant species, but most of these results record only the water-soluble exudates and provide no information on the sites of the exudation. Pearson and Parkinson (1961) and Schroth and Snyder (1961) reported greater exudation of compounds which reacted with ninhydrin and silver nitrate from the root tip and the elongating zone of the roots of seedlings of broad bean and French bean than from the older parts of the roots; while McDougall (1968) has reported greater exudation of 14C-labelled compounds from the lateral root zones of wheat than from the tip region. Bowen (1968) found that with Pinus radiata seedlings proportionately greater loss of 36Cl occurred from the apical region of the roots than from the basal region.

Root growth of lupins is more sensitive to waterlogging than wheat

2011 ◽  
Vol 38 (11) ◽  
pp. 910 ◽  
Author(s):  
Helen Bramley ◽  
Stephen D. Tyerman ◽  
David W. Turner ◽  
Neil C. Turner
Keyword(s):  
Root Growth ◽  
Oxygen Deficiency ◽  
Triticum Aestivum L ◽  
Wheat Root ◽  
Lupinus Luteus ◽  
Apical Region ◽  
Basal Region ◽  
Yellow Lupin ◽  
Wheat Roots ◽  
Root Death

In south-west Australia, winter grown crops such as wheat and lupin often experience transient waterlogging during periods of high rainfall. Wheat is believed to be more tolerant to waterlogging than lupins, but until now no direct comparisons have been made. The effects of waterlogging on root growth and anatomy were compared in wheat (Triticum aestivum L.), narrow-leafed lupin (Lupinus angustifolius L.) and yellow lupin (Lupinus luteus L.) using 1 m deep root observation chambers. Seven days of waterlogging stopped root growth in all species, except some nodal root development in wheat. Roots of both lupin species died back progressively from the tips while waterlogged. After draining the chambers, wheat root growth resumed in the apical region at a faster rate than well-drained plants, so that total root length was similar in waterlogged and well-drained plants at the end of the experiment. Root growth in yellow lupin resumed in the basal region, but was insufficient to compensate for root death during waterlogging. Narrow-leafed lupin roots did not recover; they continued to deteriorate. The survival and recovery of roots in response to waterlogging was related to anatomical features that influence internal oxygen deficiency and root hydraulic properties.

scholarly journals Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Apical Region ◽  
Basal Region ◽  
Specific Expression ◽  
Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

scholarly journals Mites fluctuation population on peach tree (Prunus persica (L.) Batsch) and in associated plants

2011 ◽  
Vol 33 (3) ◽  
pp. 765-773 ◽  
Author(s):  
Carla Rosana Eichelberger ◽  
Liana Johann ◽  
Fernanda Majolo ◽  
Noeli Juarez Ferla
Keyword(s):  
Prunus Persica ◽  
Rio Grande ◽  
Population Diversity ◽  
Panonychus Ulmi ◽  
Apical Region ◽  
Basal Region ◽  
Rio Grande Do Sul ◽  
Phytophagous Mites ◽  
Phytoseiulus Macropilis ◽  
Tetranychus Ludeni

Despite the importance of peach (Prunus persica (L.) Batsch) in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836) and Mononychellus planki (McGregor, 1950) were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904) the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43) when compared to Eldorado (H' 0.53; EqJ 0.40). In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939), T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and January and high predator diversity was observed on associated plants and on peach plants, indicating the existence of species mobility in peach orchard.

scholarly journals Localized Ca2+ uncaging reveals polarized distribution of Ca2+-sensitive Ca2+ release sites

2002 ◽  
Vol 158 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Michael C. Ashby ◽  
Madeleine Craske ◽  
Myoung Kyu Park ◽  
Oleg V. Gerasimenko ◽  
Robert D. Burgoyne ◽  
...  
Keyword(s):  
Ryanodine Receptors ◽  
Acinar Cells ◽  
Cell Types ◽  
Pancreatic Acinar Cells ◽  
Apical Region ◽  
Basal Region ◽  
Activation Pattern ◽  
Inositol Trisphosphate Receptors ◽  
Agonist Stimulation ◽  
Major Process

Ca2+-induced Ca2+ release (CICR) plays an important role in the generation of cytosolic Ca2+ signals in many cell types. However, it is inherently difficult to distinguish experimentally between the contributions of messenger-induced Ca2+ release and CICR. We have directly tested the CICR sensitivity of different regions of intact pancreatic acinar cells using local uncaging of caged Ca2+. In the apical region, local uncaging of Ca2+ was able to trigger a CICR wave, which propagated toward the base. CICR could not be triggered in the basal region, despite the known presence of ryanodine receptors. The triggering of CICR from the apical region was inhibited by a pharmacological block of ryanodine or inositol trisphosphate receptors, indicating that global signals require coordinated Ca2+ release. Subthreshold agonist stimulation increased the probability of triggering CICR by apical uncaging, and uncaging-induced CICR could activate long-lasting Ca2+ oscillations. However, with subthreshold stimulation, CICR could still not be initiated in the basal region. CICR is the major process responsible for global Ca2+ transients, and intracellular variations in sensitivity to CICR predetermine the activation pattern of Ca2+ waves.

An ultrastructural study of the enigmatic "rodlet cells" in the white sucker, Catostomus commersoni (Lacépède) (Pisces: Catostomidae)

1975 ◽  
Vol 53 (11) ◽  
pp. 1483-1494 ◽  
Author(s):  
Sherwin S. Desser ◽  
Robert Lester
Keyword(s):  
Golgi Complex ◽  
Spherical Inclusion ◽  
Thick Wall ◽  
Apical Region ◽  
Basal Region ◽  
White Sucker ◽  
Catostomus Commersoni ◽  
Epithelial Surface ◽  
And Function ◽  
Rodlet Cells

The cytology of immature and mature stages of a peculiar and widespread cell, the "rodlet cell" is described from the epithelium of the operculum and gill raker of the white sucker, Catostomus commersoni. Immature stages were observed in the intermediate and basal zones of the epithelium. They were spherical to ovoid in shape and surrounded by a limiting membrane, beneath which were numerous microfilaments arranged in parallel. The cytoplasm of immature rodlet cells contained a prominent "active" Golgi complex, peripherally arranged mitochondria, numerous free ribosomes, and an extensive network of distended cisternae of granular endoplasmic reticulum. Mature rodlet cells were usually observed along the epithelial surface. These fusiform cells were surrounded by a thick wall which contained circumferentially arranged microfilaments. A nucleus, a spherical inclusion, and a Golgi complex were observed in the basal region of the cell. The cytoplasm contained many closely packed vesicles. Numerous mitochondria were aggregated in the apical region of the cell, which terminated in three or more microvillus-like processes. While the nature and function of the rodlet cells is not elucidated, it is postulated that they are not protozoan parasites.

Changes in the Ultrastructure of the Root Tip of Wheat Following Exposure to Aluminium

1994 ◽  
Vol 21 (1) ◽  
pp. 85 ◽  
Author(s):  
MLD Lima ◽  
L Copeland
Keyword(s):  
Triticum Aestivum ◽  
Prolonged Exposure ◽  
Morphological Changes ◽  
Triticum Aestivum L ◽  
Root Tip ◽  
Cortical Layers ◽  
Wheat Roots ◽  
Wheat Seedlings ◽  
Meristematic Cells ◽  
Fermentative Metabolism

Investigations have been carried out on morphological changes induced by aluminium ions in roots of wheat seedlings (Triticum aestivum L. cv. Vulcan). Lesions were evident on the surface of the roots after 4-8 h of exposure, and within 24 h there was increased vacuolation, loss of turgor, and severe cytoplasmic disorganisation in epidermal and peripheral cap cells. The central cap and cortical layers were also severely damaged by aluminium, but changes in the meristematic cells became evident only after more prolonged exposure of roots to aluminium. Mobilisation of starch in amyloplasts of peripheral and central cap cells of aluminium-stressed roots was particularly noticeable, and this was accompanied by an increase in the amount of extractable activity of starch-degrading enzymes. The possibility that the mobilisation of starch is linked to a coincident increase in fermentative metabolism in Al-stressed wheat roots is considered.

scholarly journals Species-Dependent Effects of Border Cell and Root Tip Exudates on Nematode Behavior

2000 ◽  
Vol 90 (11) ◽  
pp. 1239-1245 ◽  
Author(s):  
Xiaowen Zhao ◽  
Mark Schmitt ◽  
Martha C. Hawes
Keyword(s):  
Root Tip ◽  
Apical Region ◽  
Similar Response ◽  
Quiescent State ◽  
Border Cells ◽  
Root Knot Nematode ◽  
Vitro Assay ◽  
Snap Bean ◽  
Border Cell

Effects of border cell and root tip exudates on root knot nematode (Meloidogyne incognita) behavior were examined. In whole-plant assays using pea, M. incognita second-stage juveniles (J2) accumulated rapidly around the 1- to 2-mm apical region ensheathed by border cells, but not in the region of elongation. Within 15 to 30 min, J2 which had accumulated within detached clumps of border cells lost motility and entered into a quiescent state. When border cells (and associated root tip exudates) were washed from pea roots prior to challenge with nematodes, no such accumulation and quiescence was induced. Attraction of nematodes by roots was species dependent: no attraction or accumulation occurred in snap bean. Using a quantitative assay, three categories of chemotaxis responses occurred: attraction (pea and alfalfa cv. Thor), repulsion (alfalfa cv. Moapa 69), and no response (snap bean and alfalfa cv. Lahonton). In contrast, total root tip exudates from all three plant species acted as a repellent for M. incognita in the sand assay. An in vitro assay was developed to characterize the induced quiescence response. When total root tip exudate from the tested legumes (as well as corn) was incubated with J2 populations, >80% of the nematodes lost motility. A similar response occurred in Caenorhabditis elegans. Border cell exudates did not induce or contribute to the induction of quiescence. Cocultivation of pea border cells with M. incognita resulted in changes in border cell shape similar to those observed in response to exogenous plant hormones. No such changes occurred in snap bean border cells. Understanding the cell- and host-specific extracellular recognition that occurs between roots and pathogenic nematodes in the early stages before infection occurs could lead to new avenues for disease control.

scholarly journals Pairwise Interactions of Three Related Pseudomonas Species in Plant Roots and Inert Surfaces

2021 ◽  
Vol 12 ◽  
Author(s):  
Nesli Tovi ◽  
Tomer Orevi ◽  
Maor Grinberg ◽  
Nadav Kashtan ◽  
Yitzhak Hadar ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Plant Roots ◽  
Microbial Consortia ◽  
Root Tip ◽  
Interaction Patterns ◽  
Interspecies Interactions ◽  
Wheat Roots ◽  
Pairwise Interactions ◽  
Inert Surfaces ◽  
External Stimuli

Bacteria are social organisms that interact extensively within and between species while responding to external stimuli from their environments. Designing synthetic microbial communities can enable efficient and beneficial microbiome implementation in many areas. However, in order to design an efficient community, one must consider the interactions between their members. Using a reductionist approach, we examined pairwise interactions of three related Pseudomonas species in various microenvironments including plant roots and inert surfaces. Our results show that the step between monoculture and co-culture is already very complex. Monoculture root colonization patterns demonstrate that each isolate occupied a particular location on wheat roots, such as root tip, distance from the tip, or scattered along the root. However, pairwise colonization outcomes on the root did not follow the bacterial behavior in monoculture, suggesting various interaction patterns. In addition, we show that interspecies interactions on a microscale on inert surface take part in co-culture colonization and that the interactions are affected by the presence of root extracts and depend on its source. The understanding of interrelationships on the root may contribute to future attempts to manipulate and improve bacterial colonization and to intervene with root microbiomes to construct and design effective synthetic microbial consortia.

scholarly journals Tissue-specific metabolic reprogramming during wound induced de novo organ formation in tomato hypocotyl explants

2021 ◽  
Author(s):  
Eduardo Larriba ◽  
Ana Belén Sánchez García ◽  
Cristina Martínez-Andújar ◽  
Alfonso Albacete ◽  
José Manuel Pérez-Pérez
Keyword(s):  
De Novo ◽  
Metabolic Reprogramming ◽  
Apical Region ◽  
List Type ◽  
Basal Region ◽  
Metabolic Switch ◽  
Tissue Specific ◽  
Hypocotyl Explants ◽  
Organ Formation ◽  
Organ Regeneration

SUMMARYPlants have remarkable regenerative capacity, which allows them to survive tissue damaging after biotic and abiotic stress. Some of the key transcription factors and the hormone crosstalk involved in wound-induced organ regeneration have been extensively studied in the model plant Arabidopsis thaliana. However, little is known about the role of metabolism in wound-induced organ regeneration.Here, we performed detailed transcriptome analysis and targeted metabolomics approach during de novo organ formation in tomato hypocotyl explants and found tissue-specific metabolic differences and divergent developmental pathways after wounding.Our results indicate that callus growth in the apical region of the hypocotyl depends on a specific metabolic switch involving the upregulation of the photorespiratory pathway and the differential regulation of photosynthesis-related genes and of the gluconeogenesis pathway.The endogenous pattern of ROS accumulation in the apical and basal region of the hypocotyl during the time-course were dynamically regulated, and contributed to tissue-specific wound-induced regeneration.Our findings provide a useful resource for further investigation on the molecular mechanisms involved in wound-induced organ formation in a crop species such as tomato.One-sentence SummaryMetabolic switch during wound-induced regeneration

The ultrastructual morphology of the midgut diverticulum of the calanoid copepod Calanus helgolandicus (Claus) (Crustacea)

1970 ◽  
Vol 18 (1) ◽  
pp. 9 ◽  
Author(s):  
JE Ong ◽  
PS Lake
Keyword(s):  
Amino Acids ◽  
Epithelial Cells ◽  
Myoepithelial Cell ◽  
Calanoid Copepod ◽  
Apical Region ◽  
Basal Region ◽  
Epithelial Layer ◽  
Apical Half ◽  
Mammalian Stomach ◽  
Blue Reaction

The midgut diverticulum of the marine calanoid copepod C. helgolandicus consists of a columnar epithelial layer, a myoepithelial layer, and between these a well-developed basement membrane. The apical region of the epithelial cell is thrown into tightly packed microvilli which showed an alcian blue reaction indicating the presence of acid mucopolysaccharides. The apical half of the cell contains numerous microvesicles and mitochondria as well as tiny Golgi-like bodies. The plasma membrane of the basal region of the epithelium is extremely digitated. The digitations contain numerous mitochondria and the whole structure resembles mitochondrial pumps. The epithelial cells contain a large centrally situated oval nucleus with its single nucleolus. The myoepithelial cell is squamous and contains a flattened nucleus as well as very well-developed circularly and longitudinally arranged myofibrils. It is suggested that the midgut diverticulum of Calanus is probably analogous to the mammalian stomach in that food is mechanically churned. However, it does not appear to be involved in the secretion of digestive juices but only mucopolysaccharides; it is probably involved in the absorption of amino acids which are probably actively transported, by the "mitochondrial pump" in the basal region of the epithelial cells, into the haemocoel.

Sign in / Sign up

Export Citation Format

Share Document