Cytochemical Adenosinetriphosphatase in Plant Root Meristem

1968 ◽  
Vol 3 (3) ◽  
pp. 423-436
Author(s):  
NORMA SHIFRIN ◽  
L. LEVINE
Keyword(s):  
Atpase Activity ◽  
Root Meristem ◽  
Plant Root ◽  
Root Tip ◽  
Chromosome Movement ◽  
Nuclear Membranes ◽  
Late Anaphase ◽  
Rnase Treatment ◽  
Mitotic Cells

Root tip meristems were stained to demonstrate ATPase activity by two different methods, with general agreement in localization but not specificity, and with emphasis on mitotic cells. In interphase, ATPase was localized in nucleoli and nuclear membranes, with lesser activity in the nuclear substance. In prophase, chromosomes were outlined by ATPase stain which gradually declined in intensity at prometaphase, becoming least evident in metaphase. Staining activity increased again in anaphase, and remained high in telophase. In prometaphase, anaphase and late anaphase--early telophase, the ATPase was concentrated in a fibril which appeared to coil around the chromosomes. The ATPase fibril was thinnest at metaphase and shorter and thicker at telophase. In addition, granules formed in association with the coils of the fibril in late anaphase and early telophase. Later on, these granules may have fused and contributed to nucleolar reformation. The ATPase never localized in the chromosomal fibre nor in any other region of the spindle. RNA generally localized like ATPase, but ATPase loci were unchanged after ribonuclease (RNase) treatment. Because of certain similarities between ATPase and argentaffin localization, some relationship between the nucleolus and ATPase is suggested. A mechanochemical transducing role is postulated for the ATPase, because cytochemical properties were like those of ATPase in the A-band of myofibrillae, and because other changes in it could be correlated with chromosome movement.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Histochemical Examination of Invertase Activities in the Growing Tip of the Plant Root

2017 ◽  
Vol 10 (1) ◽  
pp. 35-45
Author(s):  
N.F. Lunkova ◽  
N.A. Burmistrova ◽  
M.S. Krasavina
Keyword(s):  
Plant Root ◽  
Invertase Activity ◽  
Root Tip ◽  
Elongation Zone ◽  
Root Tips ◽  
Phloem Unloading ◽  
Meristem Cell ◽  
Transition To Elongation ◽  
Different Tissues

Background:A growing part of the root is one of the most active sinks for sucrose coming from source leaves through the phloem. In the root, sucrose is unloaded from conducting bundles and is distributed among the surrounding cells. To be involved in the metabolism, sucrose should disintegrate into hexoses by means of degrading enzymes.Aims:The aim of this research was to explore the possibility of the involvement of one such enzymes, invertase, in phloem unloading as well as distribution of its activity in the functionally different tissues of the plant root tips.Method:To estimate the enzyme activities in root tissues, we applied two techniques: the histochemical method using nitro blue tetrazolium. The localization of phloem unloading was studied with carboxyfluorescein, a fluorescent marker for symplastic transport.Results:Invertase activity was not detected in the apical part of the meristem. It appeared only between the basal part of this zone and the beginning of the elongation zone. There is the root phloem unloading in that area. Invertase activity increased with increasing the distance from the root tip and reached the highest values in the region of cell transition to elongation and in the elongation zone. The activities of the enzyme varied in different tissues of the same zone and sometimes in the neighboring cells of the same tissue. Biochemical determination of invertase activity was made in the maize root segments coincident to the zones of meristem, cell elongation and differentiation. The results of both methods of determination of invertase activity were in agreement.Conclusion:It was concluded that phloem unloading correlated with invertase activity, possibly because of the activation of invertase by unloaded sucrose. Invertase is one of the factors involved in the processes preparing the cells for their transition to elongation because the concentration of osmotically active hexoses increases after cleavage of sucrose, that stimulates water entry into the cells, which is necessary for elongation growth.

Proteomic Analyses of Soybean Root Tips During Germination

2014 ◽  
Vol 21 (12) ◽  
pp. 1308-1319
Author(s):  
Setsuko Komatsu ◽  
Myeong W. Oh ◽  
Hee Y. Jang ◽  
Soo J. Kwon ◽  
Hye R. Kim ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Proteomic Analysis ◽  
Plant Root ◽  
Root Tip ◽  
Root Tips ◽  
Form Complex ◽  
Molecular Weights ◽  
Soybean Seedlings ◽  
2D Gel ◽  
Proteomic Techniques

Plant root systems form complex networks with the surrounding soil environment and are controlled by both internal and external factors. To better understand the function of root tips of soybean during germination, three proteomic techniques were used to analyze the protein profiles of root tip cells. Proteins were extracted from the root tips of 4-dayold soybean seedlings and analyzed using two-dimensional (2D) gel electrophoresis-based proteomics, SDS-gel based proteomics, and gel-free proteomics techniques. A total of 121, 862, and 341 proteins were identified in root tips using the 2D gel-based, SDS gel-based, and gel-free proteomic techniques, respectively. The proteins identified by 2D gel-based proteomic analysis were predominantly localized in the cytoplasm, whereas nuclear-localized proteins were most commonly identified by the SDS gel-based and gel-free proteomics techniques. Of the 862 proteins identified in the SDS gelbased proteomic analysis, 190 were protein synthesis-related proteins. Furthermore, 24 proteins identified using the 2Dgel based proteomic technique shifted between acidic and basic isoelectric points, and 2 proteins, heat shock protein 70.2 and AAA-type ATPase, displayed two different molecular weights at the same isoelectric point. Taken together, these results suggest that a number of proteins related to protein synthesis and modification are activated in the root tips of soybean seedlings during germination.

scholarly journals ACORBA: Automated workflow to measure Arabidopsis thaliana root tip angle dynamic

2021 ◽  
Author(s):  
Nelson BC Serre ◽  
Matyas Fendrych
Keyword(s):  
Plant Root ◽  
Automated Image Analysis ◽  
Root Tip ◽  
Spatiotemporal Resolution ◽  
Bending Angle ◽  
Root Angle ◽  
Root Gravitropism ◽  
Microscopy Data ◽  
Automated Software ◽  
Over Time

Plants respond to the surrounding environment in countless ways. One of these responses is their ability to sense and orient their root growth toward the gravity vector. Root gravitropism is studied in many laboratories as a hallmark of auxin-related phenotypes. However, manual analysis of images and microscopy data is known to be subjected to human bias. This is particularly the case for manual measurements of root bending as the selection lines to calculate the angle are set subjectively. Therefore, it is essential to develop and use automated or semi-automated image analysis to produce reproducible and unbiased data. Moreover, the increasing usage of vertical-stage microscopy in plant root biology yields gravitropic experiments with an unprecedented spatiotemporal resolution. To this day, there is no available solution to measure root bending angle over time for vertical-stage microscopy. To address these problems, we developed ACORBA (Automatic Calculation Of Root Bending Angles), a fully automated software to measure root bending angle over time from vertical-stage microscope and flatbed scanner images. Moreover, the software can be used semi-automated for camera, mobile phone or stereomicroscope images. ACORBA represents a flexible approach based on both traditional image processing and deep machine learning segmentation to measure root angle progression over time. By its automated nature, the workflow is limiting human interactions and has high reproducibility. ACORBA will support the plant biologist community by reducing time and labor and by producing quality results from various kinds of inputs.

Advances in understanding plant root hairs in relation to nutrient acquisition and crop root function

2021 ◽  
pp. 127-162
Author(s):  
Timothy S. George ◽  
◽  
Lawrie K. Brown ◽  
A. Glyn Bengough ◽  
◽  
...  
Keyword(s):  
Plant Root ◽  
Root Hairs ◽  
Microbial Interactions ◽  
Flowering Plant ◽  
Agricultural Sustainability ◽  
Root Tip ◽  
Pattern Length ◽  
Crop Root ◽  
Flowering Plant Species ◽  
And Function

Root hairs are found on most terrestrial flowering plant species. They form from epidermal cells at a predetermined distance behind the growing root tip in three main patterns. Their presence, pattern, length, density and function are genetically controlled and numerous genes are expressed solely in root hairs. Their growth and proliferation are attenuated by the environment and root hairs growing in soil are generally shorter and less dense than those in laboratory studies. Root hairs have a number of functions including anchorage, root soil contact and bracing to enable roots to penetrate hard soils. However, their primary function is acquisition of nutrients and water, in particular phosphate. They are the site of transporters, exudation of active compounds and infection point of symbiotic microbial interactions. They have a profound effect on rhizosphere characteristics and are a potentially useful target for breeding crops for future agricultural sustainability.

3D Analysis of Mitosis Distribution Pattern in the Plant Root Tip with iRoCS Toolbox

2019 ◽  
pp. 119-125 ◽  
Author(s):  
Viktoriya V. Lavrekha ◽  
Taras Pasternak ◽  
Klaus Palme ◽  
Victoria V. Mironova
Keyword(s):  
Distribution Pattern ◽  
Plant Root ◽  
Root Tip ◽  
3D Analysis

scholarly journals Identification of three LRR-RKs involved in perception of root meristem growth factor in Arabidopsis

2016 ◽  
Vol 113 (14) ◽  
pp. 3897-3902 ◽  
Author(s):  
Hidefumi Shinohara ◽  
Ayaka Mori ◽  
Naoko Yasue ◽  
Kumiko Sumida ◽  
Yoshikatsu Matsubayashi
Keyword(s):  
Stem Cell ◽  
Growth Factor ◽  
Root Meristem ◽  
Root Tip ◽  
Cell Area ◽  
Elongation Zone ◽  
Short Root ◽  
Triple Mutant ◽  
Custom Made ◽  
Meristem Development

A peptide hormone, root meristem growth factor (RGF), regulates root meristem development through the PLETHORA (PLT) stem cell transcription factor pathway, but it remains to be uncovered how extracellular RGF signals are transduced to the nucleus. Here we identified, using a combination of a custom-made receptor kinase (RK) expression library and exhaustive photoaffinity labeling, three leucine-rich repeat RKs (LRR-RKs) that directly interact with RGF peptides in Arabidopsis. These three LRR-RKs, which we named RGFR1, RGFR2, and RGFR3, are expressed in root tissues including the proximal meristem, the elongation zone, and the differentiation zone. The triple rgfr mutant was insensitive to externally applied RGF peptide and displayed a short root phenotype accompanied by a considerable decrease in meristematic cell number. In addition, PLT1 and PLT2 protein gradients, observed as a gradual gradient decreasing toward the elongation zone from the stem cell area in wild type, steeply declined at the root tip in the triple mutant. Because RGF peptides have been shown to create a diffusion-based concentration gradient extending from the stem cell area, our results strongly suggest that RGFRs mediate the transformation of an RGF peptide gradient into a PLT protein gradient in the proximal meristem, thereby acting as key regulators of root meristem development.

scholarly journals Tissue growth constrains root organ outlines into an isometrically scalable shape

Development ◽  
2021 ◽  
Vol 148 (4) ◽  
pp. dev196253
Author(s):  
Motohiro Fujiwara ◽  
Tatsuaki Goh ◽  
Satoru Tsugawa ◽  
Keiji Nakajima ◽  
Hidehiro Fukaki ◽  
...  
Keyword(s):  
Plant Root ◽  
Lateral Roots ◽  
Time Lapse ◽  
Tissue Growth ◽  
Root Tip ◽  
Root Tips ◽  
Developmental Constraints ◽  
Primary Roots ◽  
Catenary Curve ◽  
Expansion Force

ABSTRACTOrgan morphologies are diverse but also conserved under shared developmental constraints among species. Any geometrical similarities in the shape behind diversity and the underlying developmental constraints remain unclear. Plant root tip outlines commonly exhibit a dome shape, which likely performs physiological functions, despite the diversity in size and cellular organization among distinct root classes and/or species. We carried out morphometric analysis of the primary roots of ten angiosperm species and of the lateral roots (LRs) of Arabidopsis, and found that each root outline was isometrically scaled onto a parameter-free catenary curve, a stable structure adopted for arch bridges. Using the physical model for bridges, we analogized that localized and spatially uniform occurrence of oriented cell division and expansion force the LR primordia (LRP) tip to form a catenary curve. These growth rules for the catenary curve were verified by tissue growth simulation of developing LRP development based on time-lapse imaging. Consistently, LRP outlines of mutants compromised in these rules were found to deviate from catenary curves. Our analyses demonstrate that physics-inspired growth rules constrain plant root tips to form isometrically scalable catenary curves.

scholarly journals PIEZO ion channel is required for root mechanotransduction in Arabidopsis thaliana

2020 ◽  
Author(s):  
Seyed A. R. Mousavi ◽  
Adrienne E Dubin ◽  
Wei-Zheng Zeng ◽  
Adam M. Coombs ◽  
Khai Do ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Ion Channels ◽  
Ion Channel ◽  
Mammalian Cells ◽  
Plant Root ◽  
Mechanical Strain ◽  
Root Tip ◽  
Root Tips ◽  
Mechanosensitive Ion Channels ◽  
Mechanical Constraints

SummaryPlant roots adapt to the mechanical constraints of the soil to grow and absorb water and nutrients. As in animal species, mechanosensitive ion channels in plants are proposed to transduce external mechanical forces into biological signals. However, the identity of these plant root ion channels remains unknown. Here, we show that Arabidopsis thaliana PIEZO (AtPIEZO) has preserved the function of its animal relatives and acts as an ion channel. We present evidence that plant PIEZO is highly expressed in the columella and lateral root cap cells of the root tip which experience robust mechanical strain during root growth. Deleting PIEZO from the whole plant significantly reduced the ability of its roots to penetrate denser barriers compared to wild type plants. piezo mutant root tips exhibited diminished calcium transients in response to mechanical stimulation, supporting a role of AtPIEZO in root mechanotransduction. Finally, a chimeric PIEZO channel that includes the C-terminal half of AtPIEZO containing the putative pore region was functional and mechanosensitive when expressed in naive mammalian cells. Collectively, our data suggest that Arabidopsis PIEZO plays an important role in root mechanotransduction and establishes PIEZOs as physiologically relevant mechanosensitive ion channels across animal and plant kingdoms.

scholarly journals Lateral Root Traits of Taxodium Hybrid ‘Zhongshanshan 406’ in Response to Drought Stress

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 547-551
Author(s):  
Qin Shi ◽  
Yunlong Yin ◽  
Zhiquan Wang ◽  
Wencai Fan ◽  
Jinbo Guo ◽  
...  
Keyword(s):  
Drought Stress ◽  
Surface Area ◽  
Root Length ◽  
Lateral Root ◽  
Plant Root ◽  
Lateral Roots ◽  
Specific Root Length ◽  
Root Traits ◽  
Root Tip ◽  
Root Surface Area

Roots are vital organs for resource uptake. However, the knowledge regarding the extent by which responses in roots influence plant resistance is still poorly known. In this study, we examined the morphological and physiological responses of lateral roots of Taxodium hybrid ‘Zhongshanshan 406’ (Taxodium mucronatum♀ and Taxodium distichum♂, T. 406) to 8 (DS-8) and 12 days (DS-12) drought. Control plants (CK-8 and CK-12) were well-watered throughout the experiment. Results indicated that drought resulted in significantly decreased root length, surface area, volume, and biomass and a relatively high death rate of roots (>2 mm). Specific root length (SRL) and specific root surface area (SRA) of drought-stressed T. 406 plants were reduced to enhance resource uptake. Meanwhile, root relative water content (RWC) of T. 406 plants in CK-12 treatment was 5.81 times of those in DS-12 treatment. Under drought stress and root superoxide dismutase and ascorbic acid (ASA) activities, proline and hydrogen peroxide (H2O2) contents consistently increased to benefit the elimination of O2−. At the ultrastructural level, the organelle structure of T. 406 plant root tip was visibly damaged because of dehydration. The nucleus swelled and then exhibited uncommon features of disorganization and disruption. In short, our results provided substantial information about lateral root traits of T. 406 plants in response to drought stress, which is crucial to improve the drought resistance of Taxodium hybrid in the future breeding.

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