scholarly journals The modification of method of the artificial inoculation of sunflower seedlings with Phoma rot pathogen in the laboratory conditions to identify the colonizing activity of strains-producer of microbiopreparations

2020 ◽  
Vol 4 (184) ◽  
pp. 52-56
Author(s):  
L.V. Maslienko ◽  
◽  
A.Kh. Voronkova ◽  
L.A. Datsenko ◽  
E.A. Efimtseva ◽  
...  
Keyword(s):  
Early Stage ◽  
Lateral Roots ◽  
Artificial Inoculation ◽  
Root Tip ◽  
Root Tips ◽  
Laboratory Conditions ◽  
Oil Crops ◽  
Russian Research Institute ◽  
The Difference ◽  
Intensive Development

We carried the work in the biomethod laboratory of the crop management department of V.S. Pustovoit All-Russian Research Institute of Oil Crops. We modified the method of artificial inoculation of sunflower seedlings with a pathogen in a laboratory conditions for the secondary screening of antagonist strains from the collection of the biomethod laboratory to Phoma rot pathogen. We developed a five-point scale for evaluation of affection degree of sunflower seedlings by Phoma rot pathogen: 0 points – healthy seedlings; 1 point – darkening of the root tip, intensive development of lateral roots; 2 points – darkening of the root by a third or up to the middle, but intensive development of lateral roots; 3 points – necking of rot in the middle of the root or between the hypocotyl and the root, lateral roots are poorly developed; 4 points – root rotting to the middle or necking between the hypocotyl and the root, but intensive development of lateral roots; 5 points – complete rotting of the root, lateral roots are poorly developed or absent; 1-3 – viable seedlings; 4-5 – non-viable seedlings. The optimal period of exposure of the root tips of sunflower seedlings to the pathogen colony equal to 3 hours develops an average background of infection with the pathogen (60.0 %) already on the first day, at which it is possible to evaluate at an early stage the difference between the variants by the colonizing activity of laboratory samples of microbiological preparations.

scholarly journals The impact of morphometric characteristics of plants self-pollinated sunflower lines on its lodging

2020 ◽  
Vol 4 (184) ◽  
pp. 3-11
Author(s):  
B.N. Bochkaryov ◽  
◽  
N.V. Medvedeva ◽  
E.N. Ryzhenko ◽  
◽  
...  
Keyword(s):  
Root System ◽  
Lateral Roots ◽  
Root Systems ◽  
Morphometric Characteristics ◽  
Main Root ◽  
Lodging Resistance ◽  
Oil Crops ◽  
Russian Research Institute ◽  
Top Soil ◽  
The Impact

We carried out the research in 2018-2019 at the experimental station of V.S. Pustovoit All-Russian Research Institute of Oil Crops. The aim of the research is to study the effect of certain morphometric characteristics of the overground part of plants and the architectonics of the root system on the sunflower lodging. We found significant differences in the architectonics of root systems in 17 maternal lines of sunflower: we identified three morphotypes, differing in the number and thickness of lateral roots of the first and subsequent orders, located in the top soil. We identified the sunflower lines that have a root system with a well-developed main root and many lateral roots of various orders (type A), lines with a normally developed main root and a small number of lateral roots (type B), and lines with a poorly developed main root and few lateral roots in top soil (type C). We identified the presence of both low and high lodging in sunflower lines with different types of root systems. At the same time, there is a tendency towards higher lodging in lines with root system types B and C. The line SL12 3660 showed the maximum lodging resistance during two years of observations. It may be of interest for further work as a possible source of a lodging resistance trait.

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.

Nitrate and glutamate sensing by plant roots

2005 ◽  
Vol 33 (1) ◽  
pp. 283-286 ◽  
Author(s):  
S. Filleur ◽  
P. Walch-Liu ◽  
Y. Gan ◽  
B.G. Forde
Keyword(s):  
Root Growth ◽  
Lateral Root ◽  
Lateral Roots ◽  
Primary Root ◽  
Root Tip ◽  
Root Tips ◽  
Environmental Signals ◽  
Specific Effects ◽  
Large Numbers ◽  
Low Concentrations

The architecture of a root system plays a major role in determining how efficiently a plant can capture water and nutrients from the soil. Growth occurs at the root tips and the process of exploring the soil volume depends on the behaviour of large numbers of individual root tips at different orders of branching. Each root tip is equipped with a battery of sensory mechanisms that enable it to respond to a range of environmental signals, including nutrients, water potential, light, gravity and touch. We have previously identified a MADS (MCM1, agamous, deficiens and SRF) box gene (ANR1) in Arabidopsis thaliana that is involved in modulating the rate of lateral root growth in response to changes in the external NO3− supply. Transgenic plants have been generated in which a constitutively expressed ANR1 protein can be post-translationally activated by treatment with dexamethasone (DEX). When roots of these lines are treated with DEX, lateral root growth is markedly stimulated but there is no effect on primary root growth, suggesting that one or more components of the regulatory pathway that operate in conjunction with ANR1 in lateral roots may be absent in the primary root tip. We have recently observed some very specific effects of low concentrations of glutamate on root growth, resulting in significant changes in root architecture. Experimental evidence suggests that this response involves the sensing of extracellular glutamate by root tip cells. We are currently investigating the possible role of plant ionotropic glutamate receptors in this sensory mechanism.

scholarly journals Protocorm-like Bodies Initiation from Root Tips of Cyrtopodium paranaense (Orchidaceae)

HortScience ◽  
2010 ◽  
Vol 45 (9) ◽  
pp. 1365-1368 ◽  
Author(s):  
Wei-Ling Guo ◽  
Yao-Chien Alex Chang ◽  
Chien-Yuan Kao
Keyword(s):  
Acetic Acid ◽  
Seed Germination ◽  
Synergistic Effect ◽  
Early Stage ◽  
Root Apex ◽  
Root Tip ◽  
Ms Medium ◽  
Root Tips ◽  
Terrestrial Orchid ◽  
Indole 3 Acetic Acid

Cyrtopodium paranaense is a tropical terrestrial orchid, which propagates mainly through sexual seed germination. In this study, we document the asexual morphogenesis of the root tip to protocorm-like body (PLB) conversion in Cyrtopodium paranaense. Protocorm-like bodies sporadically developed from root tips of flask-grown seedlings in the absence of any exogenous plant growth regulators (PGRs). The compact PLBs ultimately gave rise to normal plantlets. Histological observations revealed that the root cap became dissociated from the root apex at an early stage followed by dispersed extension of root vascular strands into nascent PLBs. Protocorm-like bodies also developed from the root central stele tissue. In root tip segment cultures, PLBs were not formed without providing PGRs but were efficiently formed from root tips in Murashige and Skoog (MS) medium supplemented with 10.2 μM indole-3-acetic acid (IAA) and 9.0 μM thidiazuron (TDZ). Both IAA and TDZ promoted the formation of PLBs; however, TDZ did not induce PLB formation in the absence of IAA, indicating a synergistic effect of the two PGRs. Protocorm-like bodies were proliferated and subsequently plants regenerated in PGR-free MS medium. Root tip culture may be used as an alternative method for the propagation of Cyrtopodium paranaense.

RESISTANCE OF SUNFLOWER BREEDING MATERIAL TO PHOMOSIS DAMAGE

1970 ◽  
pp. 64-67
Author(s):  
S. L. Saukova ◽  
T. S. Antonova ◽  
N. M. Araslanova ◽  
М. V. Ivebor ◽  
Е. N. Ryzhenko
Keyword(s):  
Variable Temperature ◽  
Fungal Spores ◽  
Artificial Inoculation ◽  
Leaf Petiole ◽  
Oil Crops ◽  
First Case ◽  
Russian Research Institute ◽  
The Comparative Study ◽  
Syringe Injection ◽  
Russian Research

The comparative study of sunflower constant lines resistance to Phoma rot using different methods of artificial inoculation with the disease pathogen was conducted. The most aggressive isolate of the Phoma rot pathogen Plenodomus lindquistii was used for inoculation. It was isolated from the stem of the affected sunflower plant in the breeding nursery of V.S. Pustovoit All-Russian Research Institute of Oil Crops. In a greenhouse conditions, there were used two methods of artificial inoculation with a fungus at bottom of the leaf petiole of sunflower plants at the stage of the first pair of true leaves. In the first case agar pieces with mycelium, pycnidia, and picnospores were applied; in the second one 0.2 ml of the suspension of fungal spores was introduced by syringe injection. In the two control variants, plants were injected with sterile water, or pieces of sterile agar nutrient medium OA (oatmeal agar) were applied to them. The number of replications was four (10 plants each). The plants were cultivated at a variable temperature of 25-30 oС during the day and 25 оС at night (16-hour photoperiod). The cultivation duration was until the budding stage, and we recorded the affection on the 30th day after the start of inoculation. The intensity of the Phoma rot development was determined using a five-point immunological scale. The first method of inoculation (without injury) revealed resistant (VK 900, L 86) and mid-resistant (L 107, L 132) sunflower lines. The second method identified five susceptible (L 2385, L 103, L 136, L 131, L 128) and one highly susceptible (L 82) sunflower lines. In laboratory, the inoculation of the roots of sunflower seedlings by the quick test revealed two constant lines L 116 and L 136 with more than 50 % of plants with healthy root systems or with a small affection degree (1 point). Lines L 2385, L 103, L 131, and L 120 showed the largest number of plants with a medium degree of root affection (2 and 3 points). The resistance of stem and roots to Phoma rot affection in different sunflower lines was manifested both in combination and separately, which should be taken into consideration when selecting genotypes resistant to Phoma rot.

scholarly journals Survival of Plants During Short-Term BOA-OH Exposure: ROS Related Gene Expression and Detoxification Reactions Are Accompanied With Fast Membrane Lipid Repair in Root Tips

2022 ◽  
Author(s):  
Laura Laschke ◽  
Vadim Schütz ◽  
Oliver Schackow ◽  
Dieter Sicker ◽  
Lothar Hennig ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Root Zone ◽  
Membrane Lipids ◽  
Lateral Roots ◽  
Root Hairs ◽  
Membrane Lipid ◽  
Root Tip ◽  
Root Tips ◽  
Short Term ◽  
Specific Reactions

AbstractFor the characterization of BOA-OH insensitive plants, we studied the time-dependent effects of the benzoxazolinone-4/5/6/7-OH isomers on maize roots. Exposure of Zea mays seedlings to 0.5 mM BOA-OH elicits root zone-specific reactions by the formation of dark rings and spots in the zone of lateral roots, high catalase activity on root hairs, and no visible defense reaction at the root tip. We studied BOA-6-OH- short-term effects on membrane lipids and fatty acids in maize root tips in comparison to the benzoxazinone-free species Abutilon theophrasti Medik. Decreased contents of phosphatidylinositol in A. theophrasti and phosphatidylcholine in maize were found after 10–30 min. In the youngest tissue, α-linoleic acid (18:2), decreased considerably in both species and recovered within one hr. Disturbances in membrane phospholipid contents were balanced in both species within 30–60 min. Triacylglycerols (TAGs) were also affected, but levels of maize diacylglycerols (DAGs) were almost unchanged, suggesting a release of fatty acids for membrane lipid regeneration from TAGs while resulting DAGs are buildings blocks for phospholipid reconstitution, concomitant with BOA-6-OH glucosylation. Expression of superoxide dismutase (SOD2) and of ER-bound oleoyl desaturase (FAD2-2) genes were contemporaneously up regulated in contrast to the catalase CAT1, while CAT3 was arguably involved at a later stage of the detoxification process. Immuno-responses were not elicited in short-terms, since the expression of NPR1, POX12 were barely affected, PR4 after 6 h with BOA-4/7-OH and PR1 after 24 h with BOA-5/6-OH. The rapid membrane recovery, reactive oxygen species, and allelochemical detoxification may be characteristic for BOA-OH insensitive plants.

scholarly journals 646 Comparison of Ca and B Deficiency Effects on Growth and Development of Bedding Plants

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 509A-509
Author(s):  
Dharmalingam S. Pitchay ◽  
James L. Gibson ◽  
C. Ray Campbell ◽  
Paul V. Nelson ◽  
Brian E. Whipker
Keyword(s):  
Tissue Concentration ◽  
Early Stage ◽  
Lateral Roots ◽  
Bedding Plants ◽  
Deficiency Symptoms ◽  
Ca Deficiency ◽  
Margin Of Error ◽  
Necrotic Spots ◽  
The Difference ◽  
Nutrient Solutions

The margin of error in pinpointing the difference in deficiency symptoms between calcium and boron is high. Several experiments were conducted in the greenhouse to induce as well as to differentiate the exact foliar and root symptoms of Ca and B. The experiments were conducted with modified Hoagland nutrient solutions. The treatments were with or without Ca or B salts for inducing total deficiency symptoms. Symptoms were expressed on the upper part including the growing point of the plant. In absence of Ca, marigold and zinnia plant heights were reduced by 58% and 37%, respectively, from the control. However, the reduction in height was only in the 27% and 25% range for B deficiency. Ca deficiency was noted as a blackened region on the leaf blade (early stage symptoms) which progressed into necrotic spots on the newly formed leaves. Severe necrosis, was observed on the growing point with advanced Ca deficiency. B deficiency results in a leathery and gray color in zinnia, needle like and narrow leaflets in marigold. The leaf blades were brittle in all B deficient species. B deficient plants roots were stiff and leathery and lateral roots possessed black nodule like endings at the tips. The Ca deficient roots expressed less side branching and at the advanced stage the roots were shorter and fewer with severe necrotic symptoms. The above initial and advanced deficiency symptoms appeared earlier in treatments without Ca than B. Images of Ca and B deficiency symptoms, as well as tissue concentration values will be presented.

scholarly journals Homeobox transcription factor OsZHD2 promotes root meristem activity in rice by inducing ethylene biosynthesis

2020 ◽  
Vol 71 (18) ◽  
pp. 5348-5364
Author(s):  
Jinmi Yoon ◽  
Lae-Hyeon Cho ◽  
Wenzhu Yang ◽  
Richa Pasriga ◽  
Yunfei Wu ◽  
...  
Keyword(s):  
Root Meristem ◽  
Lateral Roots ◽  
Homeobox Gene ◽  
Ethylene Biosynthesis ◽  
Activation Tagging ◽  
Root Tip ◽  
Wild Type ◽  
Root Tips ◽  
Overexpression Line ◽  
Homeobox Transcription Factor

Abstract Root meristem activity is the most critical process influencing root development. Although several factors that regulate meristem activity have been identified in rice, studies on the enhancement of meristem activity in roots are limited. We identified a T-DNA activation tagging line of a zinc-finger homeobox gene, OsZHD2, which has longer seminal and lateral roots due to increased meristem activity. The phenotypes were confirmed in transgenic plants overexpressing OsZHD2. In addition, the overexpressing plants showed enhanced grain yield under low nutrient and paddy field conditions. OsZHD2 was preferentially expressed in the shoot apical meristem and root tips. Transcriptome analyses and quantitative real-time PCR experiments on roots from the activation tagging line and the wild type showed that genes for ethylene biosynthesis were up-regulated in the activation line. Ethylene levels were higher in the activation lines compared with the wild type. ChIP assay results suggested that OsZHD2 induces ethylene biosynthesis by controlling ACS5 directly. Treatment with ACC (1-aminocyclopropane-1-carboxylic acid), an ethylene precursor, induced the expression of the DR5 reporter at the root tip and stele, whereas treatment with an ethylene biosynthesis inhibitor, AVG (aminoethoxyvinylglycine), decreased that expression in both the wild type and the OsZHD2 overexpression line. These observations suggest that OsZHD2 enhances root meristem activity by influencing ethylene biosynthesis and, in turn, auxin.

scholarly journals To artificial inoculation of sunflower plants with modern pathotypes of rust for breeding on immunity

2021 ◽  
Vol 187 (3) ◽  
pp. 58-64
Author(s):  
N.М. Araslanova ◽  
◽  
T.S. Antonova ◽  
S.L. Saukova ◽  
M.V. Ivebor ◽  
...  
Keyword(s):  
Incubation Period ◽  
Rapid Identification ◽  
Artificial Inoculation ◽  
Puccinia Helianthi ◽  
Oil Crops ◽  
Russian Research Institute ◽  
Optimal Temperature Range ◽  
Different Temperatures ◽  
Speed Up ◽  
New Races

Under global warming of the last decade, there is observed an intensive spread of rust in sunflower fields in the Russian Federation, due to the emergence of new races of the pathogen. It is obvious that there is a need to breed sunflower for resistance to new pathotypes and to correct the technique of artificial inoculation of plants in relation to them. Sunflower breeding for rust resistance has not been carried out since the 1980s. Objective of the study is determining the optimal temperature range for artificial inoculation of sunflower leaves with modern pathotypes (300 and 700) of the rust pathogen. The work was performed in the laboratory of immunity of the V.S. Pustovoit All-Russian Research Institute of Oil Crops in 2020–2021 using monopustular isolates of Puccinia helianthi with virulence codes 300 and 700. The germination of mature urediniospores, the duration of the incubation period and the degree of damage to sunflower plants at different temperatures were studied. The incubation period of pathotypes 300 and 700 of P. helianthi at a temperature of 26–28 °C is reduced by 2–3 days, which is essential both for the rapid identification of the racial identity of the pathogen isolates and for shortening the period for assessing sunflower genotypes when breeding for immunity. To speed up this work, the infection of sunflower plants should be carried out in the phase of the first pair of true leaves at a temperature of 22 °C, followed by a 24-hour stay in a humid chamber at 20 °C and a further increase in the growing temperature to 26–28 °C.

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.

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