Involvement of ethylene in ectomycorrhiza formation and dichotomous branching of roots of mugo pine seedlings

1989 ◽  
Vol 67 (2) ◽  
pp. 477-482 ◽  
Author(s):  
L. A. Rupp ◽  
K. W. Mudge ◽  
F. B. Negm
Keyword(s):  
Root Growth ◽  
Laccaria Laccata ◽  
Pinus Mugo ◽  
Silver Thiosulfate ◽  
Root Branching ◽  
Pine Seedlings ◽  
Mycorrhiza Formation ◽  
Endogenous Ethylene ◽  
Ethylene Action

The role of ethylene in mycorrhiza formation and root development on axenically grown seedlings of Pinus mugo Turra var. mugo was examined. Mycorrhizal formation by Laccaria laccata and Pisolithus tinctorius in a defined liquid medium was associated with increased ethylene production. Ethephon (100 μM) stimulated dichotomous branching of roots inoculated with P. tinctorius, but had no effect on those inoculated with L. laccata, or on uninoculated roots. Ethephon had no effect on the percentage of susceptible roots that became mycorrhizal with either fungus. The inhibitor of ethylene action, silver thiosulfate, had no significant effect on mycorrhiza formation by P. tinctorius, but it did show a trend toward decreased mycorrhiza formation by L. laccata when applied at concentrations of 10 μM or higher. Silver thiosulfate at 100 or 500 μM slightly increased dichotomous root branching of seedlings inoculated with either fungus, but these concentrations also caused blackening of root meristems and inhibition of root growth. These results are consistent with the interpretation that endogenous ethylene may influence mycorrhiza formation and associated changes in root morphology.

Root responses of triticale and soybean to soil compaction in the field are reproducible under controlled conditions

2016 ◽  
Vol 43 (2) ◽  
pp. 114 ◽  
Author(s):  
Tino Colombi ◽  
Achim Walter
Keyword(s):  
Root Growth ◽  
Soil Compaction ◽  
Root Systems ◽  
Oxygen Availability ◽  
Compacted Soils ◽  
Root Branching ◽  
Controlled Conditions ◽  
Glycine Max L ◽  
Limited Oxygen

Soil compaction includes a set of underlying stresses that limit root growth such as increased impedance and limited oxygen availability. The aims of the present study were to (i) find acclimations of triticale (× Triticosecale) and soybean (Glycine max L.) roots to compacted soils in the field; (ii) reproduce these under controlled conditions; and (iii) associate these responses with soil physical properties. To this end, plants were grown at two different soil bulk densities in the field and under controlled conditions representing mature root systems and the seedling stage respectively. Diameters, lateral branching densities, the cortical proportion within the total root cross-section and the occurrence of cortical aerenchyma of main roots were quantified. Soil compaction caused decreasing root branching and increasing cortical proportions in both crops and environments. In triticale, root diameters and the occurrence of aerenchyma increased in response to compaction in the field and under controlled conditions. In soybean, these acclimations occurred at an initial developmental stage but due to radial root growth not in mature roots. These results showed that responses of root systems to compacted soils in the field are, to a large extent, reproducible under controlled conditions, enabling increased throughput, phenotyping-based breeding programs in the future. Furthermore, the occurrence of aerenchyma clearly indicated the important role of limited oxygen availability in compacted soils on root growth.

scholarly journals 125 THE ROLE OF ETHYLENE IN THE DEVELOPMENT OF CONSTANT-LIGHT INJURY OF POTATO

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 446c-446
Author(s):  
K. E. Cushman ◽  
T. W. Tibbitts
Keyword(s):  
Solanum Tuberosum ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Light Period ◽  
Constant Light ◽  
Silver Thiosulfate ◽  
Ethylene Action ◽  
Teflon Film ◽  
Necrotic Spotting

Chlorosis and necrotic spotting develop on expanding leaves of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light and temperature conditions. Plantlets of a constant-light sensitive cultivar, Kennebec, were planted into peat:vermiculite and established at 18C for 10 d under a 12 h light: 12 h dark photoperiod. Plants were then exposed to constant light and sprayed with 1 ml of either 0.5 mM silver thiosulfate (STS), an ethylene-action inhibitor, or water (as a control) every 2 days. Specific `target' leaflets, 5-10 mm in length at the beginning of the constant-light period, were harvested on days 5-9 of constant light, during injury development, and placed in bags made of Teflon film for IO-15 minutes to collect ethylene. Ethylene release and necrotic spotting increased as days of constant light increased for both water and STS-treated leaves, though STS-treated leaves produced slightly less ethylene and significantly less necrotic spotting than water-treated leaves. Ethylene release was correlated with extent of necrotic spotting. STS-treated plants exhibited greater dry weight and leaf area then water-treated plants. The results indicate that ethylene is not only produced by injured leaf tissue but, in addition, that ethylene may have a role in the development of constant-light injury symptoms.

The role of endogenous ethylene in the expansion of Helianthus annuus leaves

1997 ◽  
Vol 75 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Siew Hwee Lee ◽  
David M. Reid
Keyword(s):  
Carboxylic Acid ◽  
Helianthus Annuus ◽  
Acid Treatment ◽  
Leaf Growth ◽  
Leaf Expansion ◽  
Silver Thiosulphate ◽  
Ethylene Concentration ◽  
Endogenous Ethylene ◽  
Ethylene Action

The possible role of ethylene in leaf expansion of the primary leaves of sunflower plants (Helianthus annuus) was studied. Our lowest application of ethephon promoted expansion of primary leaves. Higher concentrations of ethephon, and a range of concentrations of 1-aminocyclopropane-1-carboxylic acid, increased endogenous ethylene concentration and caused a reduction in the area of the primary leaves. The inhibition in leaf expansion induced by ethephon and 1-aminocyclopropane-1-carboxylic acid was reversed by pretreating the plants with an inhibitor of ethylene action, namely silver thiosulphate. Treating leaves with lower concentrations of aminoefhoxyvinylglycine reduced ethylene production and stimulated leaf expansion. This effect of aminoethoxyvinylglycine could be nullified by pretreating the plants with 1-aminocyclopropane-1-carboxylic acid. Treatment with silver thiosulphate enhanced leaf expansion. This indicates that endogenous ethylene normally plays a significant role in leaf expansion. Flooded and gravistimulated plants produced more ethylene and had smaller leaves. This could suggest that the increased ethylene is the main cause of the slowed leaf growth, however, only in some cases were we able to partially reverse the effect of flooding with silver thiosulphate. This indicates that there are probably many factors, in addition to increased ethylene, that inhibit leaf expansion in flooded and gravistimulated plants. Key words: ethylene, leaf expansion.

scholarly journals Auxin-induced Ethylene Synthesis during Rooting and Inhibition of Budbreak of `Royalty' Rose Cuttings

1993 ◽  
Vol 118 (5) ◽  
pp. 638-643 ◽  
Author(s):  
Wen-Quan Sun ◽  
Nina L. Bassuk
Keyword(s):  
Root Elongation ◽  
Root Formation ◽  
Adventitious Root Formation ◽  
Root Initiation ◽  
Ethylene Synthesis ◽  
Single Node ◽  
Silver Thiosulfate ◽  
Endogenous Ethylene ◽  
Ethylene Action ◽  
The Relationship

Single-node `Royalty' rose (Rosa hybrida L.) cuttings were used to examine the relationship between adventitious root formation, budbreak, and ethylene synthesis following IBA treatment. IBA was applied as a lo-second basal quick dip before rooting, and AIB, GA3, STS, and ethephon were applied either as basal dips or foliar sprays. IBA application increased rooting and inhibited budbreak of cuttings. IBA 2 600 mg·liter-1 greatly inhibited budbreak during 4 weeks of rooting. IBA treatment stimulated ethylene synthesis, which was inversely correlated with budbreak of cuttings. Ethephon also significantly inhibited budbreak. Budbreak of rose cuttings was completely prevented by repeated ethephon sprays used to maintain high endogenous ethylene levels during the first 10 days. Treatment with STS, an ethylene-action inhibitor, improved budbreak. The inhibition of budbreak by IBA treatment resulted primarily from elevated ethylene levels. Root initiation and root elongation of cuttings initially inhibited budbreak, but later promoted budbreak. Chemical names used: indole-3-butyric acid (IBA); gibberellic acid (GA3); silver thiosulfate (STS); AIB, aminoisobutyric acid (AIB); (2-chloroethyl)-phosphoric acid (ethephon).

scholarly journals Integrating N signals and root growth: the role of nitrate transceptor NRT1.1 in auxin-mediated lateral root development

2020 ◽  
Vol 71 (15) ◽  
pp. 4365-4368
Author(s):  
Katerina S Lay-Pruitt ◽  
Hideki Takahashi
Keyword(s):  
Root Growth ◽  
Root Development ◽  
Lateral Root ◽  
Auxin Biosynthesis ◽  
Root Branching ◽  
Lateral Root Development ◽  
Experimental Botany

This article comments on: Maghiaoui A, Bouguyon E, Cuesta C, Perrine-Walker F, Alcon C, Krouk G, Benková E, Nacry P, Gojon A and Bach L. 2020. The Arabidopsis NRT1.1 transceptor coordinately controls auxin biosynthesis and transport to regulate root branching in response to nitrate. Journal of Experimental Botany 71, 4480–4494.

scholarly journals Effects of warming and fertilization interacting with intraspecific competition on fine root traits of Picea asperata

2020 ◽  
Author(s):  
Dan-Dan Li ◽  
Hong-Wei Nan ◽  
Chun-Zhang Zhao ◽  
Chun-Ying Yin ◽  
Qing Liu
Keyword(s):  
Root Growth ◽  
Climate Warming ◽  
Tree Growth ◽  
Root Length ◽  
Root Biomass ◽  
Fine Root ◽  
Root Traits ◽  
Root Surface ◽  
Root Branching ◽  
Picea Asperata

Abstract Aims Competition, temperature, and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau. Although many studies have reported their individual effects on tree growth, little is known about how the interactions of competition with fertilization and temperature affect root growth. We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors. Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature (ET) and fertilization. We measured root traits, including the root tip number over the root surface (RTRS), the root branching events over the root surface (RBRS), the specific root length (SRL), the specific root area (SRA), the total fine root length and area (RL and RA), the root tips (RT) and root branching events (RB). These root traits are considered to be indicators of plant resource uptake capacity and root growth. The root biomass and the nutrient concentrations in the roots were also determined. Important Findings The results indicated that ET, fertilization and competition individually enhanced the nitrogen (N) and potassium (K) concentrations in fine roots, but they did not affect fine root biomass or root traits, including RL, RT, RA and RB. However, both temperature and fertilization, as well as their interaction, interacting with competition increased RL, RA, RT, RB, and nutrient uptake. In addition, the SRL, SRA, RTRS and RBRS decreased under fertilization, the interaction between temperature and competition decreased SRL and SRA, while the other parameters were not affected by temperature or competition. These results indicate that Picea asperata maintains a conservative nutrient strategy in response to competition, climate warming, fertilization, and their interactions. Our results improve our understanding of the physiological and ecological adaptability of trees to global change.

Probing the role of endogenous ethylene in the degreening of citrus fruit with ethylene antagonists

1993 ◽  
Vol 12 (3) ◽  
pp. 325-329 ◽  
Author(s):  
E. E. Goldschmidt ◽  
M. Huberman ◽  
R. Goren
Keyword(s):  
Citrus Fruit ◽  
Endogenous Ethylene ◽  
Ethylene Antagonists

scholarly journals Bundling up the Role of the Actin Cytoskeleton in Primary Root Growth

2021 ◽  
Vol 12 ◽  
Author(s):  
Judith García-González ◽  
Kasper van Gelderen
Keyword(s):  
Root Growth ◽  
Actin Cytoskeleton ◽  
Cell Elongation ◽  
Feedback Loop ◽  
Primary Root ◽  
Actin Binding ◽  
Actin Network ◽  
Actin Organization ◽  
Primary Root Growth

Primary root growth is required by the plant to anchor in the soil and reach out for nutrients and water, while dealing with obstacles. Efficient root elongation and bending depends upon the coordinated action of environmental sensing, signal transduction, and growth responses. The actin cytoskeleton is a highly plastic network that constitutes a point of integration for environmental stimuli and hormonal pathways. In this review, we present a detailed compilation highlighting the importance of the actin cytoskeleton during primary root growth and we describe how actin-binding proteins, plant hormones, and actin-disrupting drugs affect root growth and root actin. We also discuss the feedback loop between actin and root responses to light and gravity. Actin affects cell division and elongation through the control of its own organization. We remark upon the importance of longitudinally oriented actin bundles as a hallmark of cell elongation as well as the role of the actin cytoskeleton in protein trafficking and vacuolar reshaping during this process. The actin network is shaped by a plethora of actin-binding proteins; however, there is still a large gap in connecting the molecular function of these proteins with their developmental effects. Here, we summarize their function and known effects on primary root growth with a focus on their high level of specialization. Light and gravity are key factors that help us understand root growth directionality. The response of the root to gravity relies on hormonal, particularly auxin, homeostasis, and the actin cytoskeleton. Actin is necessary for the perception of the gravity stimulus via the repositioning of sedimenting statoliths, but it is also involved in mediating the growth response via the trafficking of auxin transporters and cell elongation. Furthermore, auxin and auxin analogs can affect the composition of the actin network, indicating a potential feedback loop. Light, in its turn, affects actin organization and hence, root growth, although its precise role remains largely unknown. Recently, fundamental studies with the latest techniques have given us more in-depth knowledge of the role and organization of actin in the coordination of root growth; however, there remains a lot to discover, especially in how actin organization helps cell shaping, and therefore root growth.

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