scholarly journals Role of Vascular Bundles in Ripening of Rice Kernel in Relation to the Locations on Panicle

1970 ◽  
Vol 39 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Fateh Muhammad CHAUDHRY ◽  
Kazuo NAGATO
Keyword(s):  
Vascular Bundles

scholarly journals Reactive oxygen species as important regulators of cell division

2020 ◽  
Author(s):  
Weiliang Qi ◽  
Li Ma ◽  
Fei Wang ◽  
Ping Wang ◽  
Junyan Wu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Wall ◽  
Cell Division ◽  
Cold Stress ◽  
Reactive Oxygen ◽  
Vascular Bundles ◽  
Oxygen Species ◽  
Root Primordia ◽  
Lateral Root Primordia

AbstractCurrently, the role of reactive oxygen species (ROS) in plant growth is a topic of interest. In this study, we discuss the role of ROS in cell division. We analyzed ROS’ impact on the stiffness of plant cell walls and whether ROS play an important role in Brassica napus’ ability to adapt to cold stress. Cultivated sterile seedlings and calli of cold-tolerant cultivar 16NTS309 were subjected to cold stress at 25°C and 4°C, respectively. Under normal conditions, O2.− mainly accumulated in the leaf edges, shoot apical meristem, leaf primordia, root tips, lateral root primordia, calli of meristematic nodular tissues, cambia, vascular bundles and root primordia, which are characterized by high division rates. After exposure to cold stress, the malondialdehyde and ROS (O2.−) contents in roots, stems and leaves of cultivar 16NTS309 were significantly higher than under non-cold conditions (P < 0.05). ROS (O2.−) were not only distributed in these zones, but also in other cells, at higher levels than under normal conditions. A strong ROS-based staining appeared in the cell wall. The results support a dual role for apoplastic ROS, in which they have direct effects on the stiffness of the cell wall, because ROS cleave cell-wall, and act as wall loosening agents, thereby either promoting or restricting cellular division. This promotes the appearance of new shoots and a strong root system, allowing plants to adapt to cold stress.

Peroxidase activity during adventitious root formation in avocado microcuttings

1995 ◽  
Vol 73 (10) ◽  
pp. 1522-1526 ◽  
Author(s):  
Maria Luisa García-Gómez ◽  
Carolina Sánchez-Romero ◽  
Antonio Heredia ◽  
Fernando Pliego-Alfaro ◽  
Araceli Barceló-Muñoz
Keyword(s):  
Peroxidase Activity ◽  
Root Formation ◽  
Adventitious Root Formation ◽  
Vascular Bundles ◽  
Root Primordia ◽  
Strong Reaction ◽  
Cambial Cell ◽  
Soluble Peroxidase ◽  
Rooting Of Cuttings

Peroxidases seem to play an important role in the regulation of auxin levels during the rooting of cuttings. In avocado, leaf peroxidase activity remained constant throughout the rooting process in the three fractions analyzed (soluble, ionically, and covalently bound to cell wall). Soluble peroxidase activity in stem basal parts increased twofold after 3 days and then remained constant until the end of the process. Cationic and anionic electrophoresis revealed a lower number of isoenzymes in the stems than in the leaves. Histological stainings at stem basal parts were also carried out to localize the enzyme activity. Peroxidase was active in all tissues at the time the cutting was taken, with vascular bundles and epidermis giving the strongest reactions. During the process of root formation peroxidase activity was closely associated with growth and differentiation processes, e.g., cambial cell division and xylogenesis; a strong reaction was also found in the developing root primordia. The possible role of peroxidases in the regulation of auxin levels during the rooting process in avocado is discussed. Key words: auxin, avocado, peroxidase, rooting.

scholarly journals The tissue structure of the vegetative organs of strawberry (Fragaria moschata Duch®)

2000 ◽  
Vol 6 (1) ◽  
Author(s):  
J. Papp ◽  
I. Lenkefi ◽  
M. Gara ◽  
P. Gracza
Keyword(s):  
Tissue Structure ◽  
Vascular Bundles ◽  
Root Structure ◽  
Lower Epidermis ◽  
Palisade Parenchyma ◽  
Vegetative Organs ◽  
Ring Shape ◽  
Central Bundle ◽  
Upper Third

The tissue structure of the vegetative organs of strawberry (root, rhizome, stolon, leaf) is discussed in this paper. The authors stated that the root structure described by Muromcev (1969) and Naumann-Seip (1989) develops further from the primary structure. It grows secondarily and the transport tissue becomes continuous having ring shape. In the primary cortex of the rhizome periderm like tissue differentiates, but according to the examinations up to now, it does not take over the role of the exodermis. The exodermis is phloboran filled primary cortex tissue with 3-4 cell rows under the rhizodermis. The development of the transport tissue of the petiole is also a new recognition. In the lower third of the petiole the transport tissue consists of 3 collaterally compound vascular bundles. In the middle third there are 5 bundles because of the separation of the central bundle and in the upper third of the petiole 7 bundles can be observed because of the ramification of the outside bundles. Therefore attention must be taken also in the case of other plants at making sections. There might be confusions in the results of the examinations if the number of bundles increases in the petiole. The tissue structure might vary depending on the origin of the tissue segment. The palisade parenchyma of the leaf blade has two layers and it is wider than the spongy parenchyma. Among the 5-6-angular cells of the upper epidermis do not develop stomata while in the lower epidermis there are a fairly lot of them.

scholarly journals The Role of Plant Origin Preparations and Phenological Stage in Anatomy Structure Changes in the Rhizogenesis of Rosa “Hurdal”

2021 ◽  
Vol 12 ◽  
Author(s):  
Marta Joanna Monder ◽  
Paweł Kozakiewicz ◽  
Agnieszka Jankowska
Keyword(s):  
Plant Extract ◽  
Anatomical Structure ◽  
Naphthalene Acetic Acid ◽  
Vascular Bundles ◽  
Stem Cuttings ◽  
Plant Origin ◽  
Phenological Stages ◽  
Indole Butyric Acid ◽  
Organic Preparation

Most old roses are difficult to root when propagated by cuttings. This research focused on the response of stem cuttings of Rosa “Hurdal” to plant origin preparations used as rhizogenesis enhancers through changes to the anatomical structure of the basal part of the stem. Cuttings derived from shoots in four phenological stages were prepared for the experiment: flower buds closed (H1); fully flowering (H2); immediately after petals have fallen (H3); 7–14 days after petals have fallen (H4). The cuttings were treated with 0.4% indole butyric acid (IBA; Ukorzeniacz Aaqua) or 0.2% naphthalene acetic acid (NAA; Ukorzeniacz Baqua), and with plant origin preparations: Algae extract (Bio Rhizotonic), Organic preparation (Root JuiceTM), and Plant extract (Bio Roots). A high rooting percentage in comparison to the control (27.5%) was obtained after treatments of the H1 cuttings with Algae extract (90%), Organic preparation (80%), and Plant extract (75%). The H4 cuttings did not root, probably as a result of an overgrowing callus and limited xylem formation. The anatomical structure of the shoot differed in subsequent phenological stages during the period of rooting in various ways, depending on the rooting enhancer used for treatment. Numerous correlations between rooting percentage and anatomical structure were proved, including the key role of vascular bundles in increasing rooting percentage by widening the vessel diameter.

Reassessment of the Role of Calcium in Development of Bitter Pit in Apple

1996 ◽  
Vol 23 (3) ◽  
pp. 237 ◽  
Author(s):  
MC Saure
Keyword(s):  
Water Stress ◽  
Cell Membranes ◽  
Apple Fruit ◽  
Primary Factor ◽  
Vascular Bundles ◽  
Extensive Evaluation ◽  
Bitter Pit ◽  
Increased Sensitivity ◽  
Secondary Function

From an extensive evaluation of the literature on effects of orchard factors on bitter pit development, the following hypothesis has been derived. The primary factor causing bitter pit is high gibberellin (GA) levels late in the season, likely resulting from excessive root activity. The increased GA levels may cause increased permeability of cell membranes in the fruit close to vascular bundles, thereby resulting in increased sensitivity of the fruit cells to post-harvest water stress. Water stress, especially after harvest, may trigger the mechanism of bitter pit development if the primary factor, establishing susceptibility, prevails over factors that reduce susceptibility. Calcium (Ca2+) deficiency could be a secondary factor, increasing an existing risk of bitter pit development. Ca2+ may stabilise the cell membranes and reduce their permeability. However, high GA levels may hamper its movement to the fruit. Externally applied growth retardants, or ripening-related endogenous GA antagonists in the fruit flesh (e.g. ethylene and ABA), could aIso reduce susceptibility to bitter pit, independently of Ca2+, by antagonising the GA effect. The limitations of the present systems, which use Ca2+ content of the apple fruit to predict bitter pit, may reflect the secondary function of Ca2+ in bitter pit development.

scholarly journals Plasma membrane-localized SlSWEET7a and SlSWEET14 regulate sugar transport and storage in tomato fruits

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xinsheng Zhang ◽  
Chaoyang Feng ◽  
Manning Wang ◽  
Tianlai Li ◽  
Xin Liu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Sugar Content ◽  
Sugar Transport ◽  
Invertase Activity ◽  
Vascular Bundles ◽  
Tomato Fruits ◽  
Sugar Transporters ◽  
Potential Strategy ◽  
And Storage

AbstractSugars, especially glucose and fructose, contribute to the taste and quality of tomato fruits. These compounds are translocated from the leaves to the fruits and then unloaded into the fruits by various sugar transporters at the plasma membrane. SWEETs, are sugar transporters that regulate sugar efflux independently of energy or pH. To date, the role of SWEETs in tomato has received very little attention. In this study, we performed functional analysis of SlSWEET7a and SlSWEET14 to gain insight into the regulation of sugar transport and storage in tomato fruits. SlSWEET7a and SlSWEET14 were mainly expressed in peduncles, vascular bundles, and seeds. Both SlSWEET7a and SlSWEET14 are plasma membrane-localized proteins that transport fructose, glucose, and sucrose. Apart from the resulting increase in mature fruit sugar content, silencing SlSWEET7a or SlSWEET14 resulted in taller plants and larger fruits (in SlSWEET7a-silenced lines). We also found that invertase activity and gene expression of some SlSWEET members increased, which was consistent with the increased availability of sucrose and hexose in the fruits. Overall, our results demonstrate that suppressing SlSWEET7a and SlSWEET14 could be a potential strategy for enhancing the sugar content of tomato fruits.

scholarly journals Seed Biopriming with Salt-Tolerant Endophytic Pseudomonas geniculata-Modulated Biochemical Responses Provide Ecological Fitness in Maize (Zea mays L.) Grown in Saline Sodic Soil

2019 ◽  
Vol 17 (1) ◽  
pp. 253 ◽  
Author(s):  
Shailendra Singh ◽  
Udai B. Singh ◽  
Mala Trivedi ◽  
Pramod Kumar Sahu ◽  
Surinder Paul ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Growth Promotion ◽  
Soluble Sugar ◽  
Toxic Effects ◽  
Limiting Factor ◽  
Vascular Bundles ◽  
Ionic Balance ◽  
Ecological Fitness ◽  
Mechanisms Of Salt Tolerance

Under changing climate, soil salinity and sodicity is a limiting factor to crop production and are considered a threat to sustainability in agriculture. A number of attempts are being made to develop microbe-based technologies for alleviation of toxic effects of salts. However, the mechanisms of salt tolerance in agriculturally important crops are not fully understood and still require in-depth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed to decipher the microbe-mediated mechanisms of salt tolerance in maize. Endophytic Pseudomonas geniculate MF-84 was isolated from maize rhizosphere and tagged with green fluorescent protein for localization in the plant system. Confocal microphotographs clearly indicate that MF-84 was localized in the epidermal cells, cortical tissues, endodermis and vascular bundles including proto-xylem, meta-xylem, phloem and bundle sheath. The role of P. geniculate MF-84 in induction and bioaccumulation of soluble sugar, proline and natural antioxidants enzymes in maize plant was investigated which lead not only to growth promotion but also provide protection from salt stress in maize. Results suggested that application of P. geniculate MF-84 reduces the uptake of Na+ and increases uptake of K+ and Ca2+ in maize roots indicative of the role of MF-84 in maintaining ionic balance/homeostasis in the plant roots under higher salt conditions. It not only helps in alleviation of toxic effects of salt but also increases plant growth along with reduction in crop losses due to salinity and sodicity.

Development of stem galls induced by Diplolepis triforma (Hymenoptera: Cynipidae) on Rosa acicularis (Rosaceae)

2006 ◽  
Vol 138 (5) ◽  
pp. 661-680 ◽  
Author(s):  
Jonathan J. Leggo ◽  
Joseph D. Shorthouse
Keyword(s):  
Phytophagous Insects ◽  
Larval Feeding ◽  
Western Canada ◽  
Vascular Bundles ◽  
Histological Techniques ◽  
Stem Gall ◽  
Key Events ◽  
First Time ◽  
Host Tissues

AbstractThe cynipid Diplolepis triforma Shorthouse and Ritchie induces a fusiform, multi chambered stem gall from leaf buds on Rosa acicularis Lindl. in central and western Canada. Galls at all stages of development were fixed and sectioned using botanical histological techniques to illustrate, for the first time, the unique host-modifying abilities of gall-inducing cynipids that distinguish them from other phytophagous insects. Key events in gall ontogeny, whereby D. triforma gains control and redirects the development of attacked host tissues to provide larvae with shelter and food, include proliferation of cytoplasmically dense parenchymatous cells within the strands of the procambium at the point of egg contact, appearance of nutritive cells when larvae first begin to feed, formation of new xylem and phloem extending from un affected vascular bundles to the larval chambers, formation of several layers of nutritive cells during the period of larval feeding, and formation of sclerenchyma cells around each larval chamber. The role of these tissues in galler biology is explained.

scholarly journals Regulation of Tomato Fruit Development by Interacting MYB Proteins

2012 ◽  
Author(s):  
Rivka Barg ◽  
Erich Grotewold ◽  
Yechiam Salts
Keyword(s):  
Transcription Factor ◽  
Fruit Development ◽  
Cell Expansion ◽  
Tomato Fruit ◽  
Phase Iii ◽  
Vascular Bundles ◽  
Positive Regulator ◽  
Differential Cell ◽  
Myb Proteins

Background to the topic: Early tomato fruit development is executed via extensive cell divisions followed by cell expansion concomitantly with endoreduplication. The signals involved in activating the different modes of growth during fruit development are still inadequately understood. Addressing this developmental process, we identified SlFSM1 as a gene expressed specifically during the cell-division dependent stages of fruit development. SlFSM1 is the founder of a class of small plant specific proteins containing a divergent SANT/MYB domain (Barg et al 2005). Before initiating this project, we found that low ectopic over-expression (OEX) of SlFSM1 leads to a significant decrease in the final size of the cells in mature leaves and fruits, and the outer pericarp is substantially narrower, suggesting a role in determining cell size and shape. We also found the interacting partners of the Arabidopsis homologs of FSM1 (two, belonging to the same family), and cloned their tomato single homolog, which we named SlFSB1 (Fruit SANT/MYB–Binding1). SlFSB1 is a novel plant specific single MYB-like protein, which function was unknown. The present project aimed at elucidating the function and mode of action of these two single MYB proteins in regulating tomato fruit development. The specific objectives were: 1. Functional analysis of SlFSM1 and its interacting protein SlFSB1 in relation to fruit development. 2. Identification of the SlFSM1 and/or SlFSB1 cellular targets. The plan of work included: 1) Detailed phenotypic, histological and cellular analyses of plants ectopically expressing FSM1, and plants either ectopically over-expressing or silenced for FSB1. 2) Extensive SELEX analysis, which did not reveal any specific DNA target of SlFSM1 binding, hence the originally offered ChIP analysis was omitted. 3) Genome-wide transcriptional impact of gain- and loss- of SlFSM1 and SlFSB1 function by Affymetrix microarray analyses. This part is still in progress and therefore results are not reported, 4) Search for additional candidate partners of SlFSB1 revealed SlMYBI to be an alternative partner of FSB1, and 5) Study of the physical basis of the interaction between SlFSM1 and SlFSB1 and between FSB1 and MYBI. Major conclusions, solutions, achievements: We established that FSM1 negatively affects cell expansion, particularly of those cells with the highest potential to expand, such as the ones residing inner to the vascular bundles in the fruit pericarp. On the other hand, FSB1 which is expressed throughout fruit development acts as a positive regulator of cell expansion. It was also established that besides interacting with FSM1, FSB1 interacts also with the transcription factor MYBI, and that the formation of the FSB1-MYBI complex is competed by FSM1, which recognizes in FSB1 the same region as MYBI does. Based on these findings a model was developed explaining the role of this novel network of the three different MYB containing proteins FSM1/FSB1/MYBI in the control of tomato cell expansion, particularly during fruit development. In short, during early stages of fruit development (Phase II), the formation of the FSM1-FSB1 complex serves to restrict the expansion of the cells with the greatest expansion potential, those non-dividing cells residing in the inner mesocarp layers of the pericarp. Alternatively, during growth phase III, after transcription of FSM1 sharply declines, FSB1, possibly through complexing with the transcription factor MYBI serves as a positive regulator of the differential cell expansion which drives fruit enlargement during this phase. Additionally, a novel mechanism was revealed by which competing MYB-MYB interactions could participate in the control of gene expression. Implications, both scientific and agricultural: The demonstrated role of the FSM1/FSB1/MYBI complex in controlling differential cell growth in the developing tomato fruit highlights potential exploitations of these genes for improving fruit quality characteristics. Modulation of expression of these genes or their paralogs in other organs could serve to modify leaf and canopy architecture in various crops.

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