scholarly journals Lignification Associated with Decreased Adventitious Rooting Competence of English Ivy Petioles

2002 ◽  
Vol 20 (4) ◽  
pp. 236-239
Author(s):  
Richard A. Reineke ◽  
Wesley P. Hackett ◽  
Alan G. Smith
Keyword(s):  
Growth And Development ◽  
Adventitious Rooting ◽  
Hedera Helix ◽  
Juvenile Phase ◽  
Mature Phase ◽  
Lignin Accumulation ◽  
The Relationship ◽  
Rooting Competence ◽  
English Ivy

Abstract English ivy (Hedera helix L.) was used to study the relationship between lignin accumulation and adventitious rooting. Juvenile-phase and three chronological ages of mature-phase petioles were collected from clonal stock plants, analyzed for quantity of vascular lignin, and placed in an in vitro rooting assay. Rooting competence was determined by observing the number of roots formed per petiole. The number of roots per petiole differed significantly between juvenile-phase and mature-phase petioles. Lignin accumulation increased during petiole growth and development with chronologically older mature-phase petioles having the greatest amounts of lignin. There was a negative correlation between lignin accumulation and adventitious rooting competence.

The identification, induction of perithecia, and pathogenicity of Gibberella (Fusarium) tricincta n.sp.

1978 ◽  
Vol 56 (18) ◽  
pp. 2203-2206 ◽  
Author(s):  
N. E. El-Gholl ◽  
J. J. McRitchie ◽  
C. L. Schoulties ◽  
W. H. Ridings
Keyword(s):  
Mass Culture ◽  
Cynodon Dactylon ◽  
Hedera Helix ◽  
Leaf Spots ◽  
In Vitro Inoculation ◽  
Sexual State ◽  
Fusarium Tricinctum ◽  
English Ivy

Fusarium was consistently isolated from leaf spots on English ivy (Hedera helix L.). This Fusarium culture (mass culture) was single spored, and three distinct pigmentation types were evident: brown, red, and white. They appeared to be cultural variants of the mycelial type and were identified as Fusarium tricinctum (Corda) Sacc. Perithecia resulting from pairings of certain combinations of these single-spored cultures, or from the mass culture, were formed on water agar containing cold-sterilized dried stem pieces of coastal Bermuda hay (Cynodon dactylon Pers.). Gibberella tricincta n.sp. is proposed for the binomial of the heterothallic sexual state, which is heretofore undescribed. In vitro inoculation of detached English ivy leaves with ascospores or conidia of the pathogen reproduced the leaf spotting originally observed; however, pathogenicity was very limited under the conditions studied.

scholarly journals TARGET CELLS FOR PATTERN FORMATION DURING ADVENTITION ROOTING IN ENGLISH IVY.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1070e-1070
Author(s):  
Robert L. Geneve
Keyword(s):  
Pattern Formation ◽  
Adventitious Root ◽  
Root Formation ◽  
Adventitious Root Formation ◽  
Target Cells ◽  
Polyamine Biosynthesis ◽  
Juvenile Phase ◽  
Mature Phase ◽  
Rooting Pattern ◽  
English Ivy

Adventitious root formation in debladed petiole cuttings of English ivy proceeds via a direct rooting pattern for the easy-to-roof juvenile phase, while the difficult-to-root mature phase roots through the indirect pattern, Juvenile petiole cuttings treated with NAA (100 μM) plus the polyamine biosynthesis inhibitor, DFMA (1 mM), formed an increased number of roots per cutting initiated through the indirect rooting pattern. The increased formation and the change in rooting pattern were reversed by the addition of putrescine (1 mM). Delaying auxin application to petiole cuttings for 15 days, also induced juvenile petioles to root by the indirect pattern. This could be reversed by rebounding the base of the cutting prior to auxin application at day 15. The data support the use of the terms “pre-competent root forming cells” (PCRFC) and `induced competent root forming cells' (ICRFC) to describe the target cells for the initial events of root formation for the direct and indirect patterns, respectively,

scholarly journals γ-Aminobutyric Acid Participates in the Adult-Phase Adventitious Rooting Recalcitrance

2020 ◽  
Author(s):  
Xu Li ◽  
Xiaozhao Xu ◽  
Fei Shen ◽  
Wei Li ◽  
Changpeng Qiu ◽  
...  
Keyword(s):  
Primary Root ◽  
Adventitious Rooting ◽  
Aminobutyric Acid ◽  
Auxin Signaling ◽  
Indole Butyric Acid ◽  
Woody Perennials ◽  
Juvenile Phase ◽  
In Vitro Shoots ◽  
Adult Phase

Abstract In many tree species especially the rooting-recalcitrant woody perennials, the adventitious root (AR) in the juvenile phase can be easily induced by exogenous auxin, but AR formation becomes recalcitrant in the adult phase. Also, it is reported that the γ-aminobutyric acid (GABA) inhibits primary root growth in Arabidopsis and the AR formation in poplar (Populus ssp). So far, how GABA affects or is affected by the ontogenetic phase or auxin remains unclear. Here, we used an apple rootstock, Malus xiaojinensis, and tobacco (Nicotiana benthamiana) to investigate this question. We first analyzed the content of GABA, the activity of GABA synthetic enzyme GAD, and the expression of the coding gene MxGADs, respectively, in leafy cuttings of juvenile and adult phase. Next, the effect of exogenous GABA on AR formation was examined in in vitro shoots of M. xiaojinensis and tobacco. Interestingly, significant and consistent increases in GABA concentration, GAD activity, and expression of MxGAD genes in response to exogenous indole butyric acid (IBA) were detected in adult-phase cuttings, but not in juvenile-phase cuttings. Exogenous GABA application inhibited the AR formation by delaying rooting time and reducing root number and the total root length in in vitro shoots of both M. xiaojinensis and tobacco. The expression of MxPIN members increased in response to IBA application, but these changes were restrained by the addition of GABA. These results indicate that both the loss of juvenility and IBA are required to trigger GABA accumulation. GABA may affect the AR formation as a co-actor by inhibiting polar auxin transport. Together, these findings facilitate the understanding of the regulatory network among GABA, juvenility, and auxin signaling on the AR formation.

scholarly journals Detecting Activity of Juvenile Phase-Specific Translocatable Substances that Influence Rooting Potential Using In Vitro Rooting Assays and Expression of a Specific Gene

1998 ◽  
Author(s):  
Wesley Hackett ◽  
Michael Raviv ◽  
Anath Das ◽  
Oded Reuveni ◽  
Arie Gutman
Keyword(s):  
Gene Expression ◽  
Mung Bean ◽  
Negative Relationship ◽  
The Body ◽  
Specific Gene ◽  
Root Initiation ◽  
Hedera Helix ◽  
Juvenile Phase ◽  
Mung Bean Hypocotyls

The objectives of the project for which substantial effort was put forth were to: 1) Verify the relationship between expression of a cDNA clone (HW103) and the rooting potential of reciprocally grafted cuttings of juvenile and mature lamina and petioles of Hedera helix L. 2) Detect rooting promoter fractions in exudates from the juvenile leaves of H. Helix by assaying for rooting with leaf petioles of juvenile and mature plants. 3) Isolate, purify and identify compounds which show activity in assays for rooting potential. Some objectives or aspects of the objectives of the original proposal were not pursued for the reasons put forth in the body of the report. The most significant findings of the project are: 1) The MS medium is a better medium than Romberg medium for performing the leaf petiole rooting assay. 2) HW103 gene expression is cell-type specific with higher levels of expression in mature than juvenile phase H. Helix petioles as evidenced by in situ hybridization which suggests a negative relationship between HW103 expression in specific cells involved in root initiation and the lack of rooting potential in mature petioles 3) HW103 gene expression may be lower in mature petioles which had been grafter to a juvenile H. Helix lamina than mature petioles that had been grafted to a mature lamina and this putative lower expression is related to formation of a higher number of roots. 4) HW103 gene expression is not related to auxin induced ethylene production. 5) Two distinct compounds that possess root initiation promoting activity can be detected mainly in diffusate of juvenile H. Helix leaves using mung bean hypocotyls and H. Helix leaf petioles in vitro. 6) H. Helix diffusate active fractions do not insistenlty promote rooting in avocado mini-cuttings. 7) Chemical identification of the active rooting compounds was not accomplished because of the death of Prof. Becker, one of the collaborators, and the resultant loss of his data. These results indicate that these may be a molecular basis for reduced rooting potential in mature H. Helix petioles and that there are diffusible (translocatable) compounds in juvenile H. Helix leaves which promote rooting in juvenile and mature H. Helix petioles and mung bean hypocotyls.

scholarly journals Root Initiation in Debladed Petioles from Juvenile and Mature English Ivy in Response to Inhibitors of Ethylene Biosynthesis and Action

1990 ◽  
Vol 115 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Robert L. Geneve ◽  
Wesley P. Hackett ◽  
Bert T. Swanson
Keyword(s):  
Ethylene Biosynthesis ◽  
Aminooxyacetic Acid ◽  
Naphthalene Acetic Acid ◽  
Root Initiation ◽  
Hedera Helix ◽  
Mature Phase ◽  
Ethylene Action ◽  
Inhibitor Treatment ◽  
English Ivy

Several inhibitors of ethylene biosynthesis and action, as well as an atmospheric ethylene scrubber, were used to investigate the role of ethylene in adventitious root initiation in de-bladed petioles from the juvenile and mature phase of English ivy (Hedera helix L.). Induction of root primordia required NAA regardless of the inhibitor treatment. Difficult-to-root mature petioles have been shown to produce higher amounts of ethylene than easy-to-root juvenile petioles. However, mature petioles failed to root under any combination of NAA and inhibitor treatment, indicating that the continued evolution of ethylene in NAA-treated mature petioles was not responsible for the absence of a rooting response. Root initiation in juvenile petioles was not affected by treatment with the ethylene action inhibitors STS and NDE, nor by removal of atmospheric ethylene with KMnO. Inhibition of ethylene biosynthesis using AVG or AOA reduced root initiation in juvenile petioles, but this response was not well-correlated to the observed reduction in ethylene evolution. The inhibitory action of AVG could not be reversed by the addition of ethylene gas or ACC, which indicated that AVG could be acting through a mechanism other than the inhibition of ethylene biosynthesis. Chemical names used: 1-naphthalene acetic acid (NAA); l-aminocyclopropane-l-carboxylic acid (ACC); silver thiosulfate (STS); 2,5-norbornadiene (NDE); aminoethyoxyvinyl-glycine (AVG); aminooxyacetic acid (AOA).

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Plasminogen Depletion during Streptokinase Treatment or Two-Chain Urokinase Incubation Correlates with Decreased Clot Lysability Ex Vivo and In Vitro

1993 ◽  
Vol 70 (06) ◽  
pp. 0998-1004 ◽  
Author(s):  
Páll T Önundarson ◽  
H Magnús Haraldsson ◽  
Lena Bergmann ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Myocardial Infarction ◽  
Ex Vivo ◽  
Time Dependent ◽  
State Variables ◽  
Thrombolytic Treatment ◽  
Direct Proportion ◽  
Plasmin Activity ◽  
Plasma Exposure ◽  
The Relationship

SummaryThe relationship between lytic state variables and ex vivo clot lysability was investigated in blood drawn from patients during streptokinase administration for acute myocardial infarction. A lytic state was already evident after 5 min of treatment and after 20 min the plasminogen concentration had decreased to 24%, antiplasmin to 7% and fibrinogen 0.2 g/1. Lysis of radiolabeled retracted clots in the patient plasmas decreased from 37 ± 8% after 5 min to 21 ± 8% at 10 min and was significantly lower (8 ± 9%, p <0.005) in samples drawn at 20, 40 and 80 min. Clot lysability correlated positively with the plasminogen concentration (r = 0.78, p = 0.003), but not with plasmin activity. Suspension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml two-chain urokinase for varying time to induce an in vitro lytic state was also associated with decreasing clot lysability in direct proportion with the duration of prior plasma exposure to urokinase. The decreased lysability correlated with the time-dependent reduction in plasminogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decreases in conjunction with the development of the lytic state and the associated plasminogen depletion. The lytic state may therefore limit reperfusion during thrombolytic treatment.

Monitoring Anticoagulant Therapy by Activated Partial Thromboplastin Time: Hirudin Assessment

1994 ◽  
Vol 72 (05) ◽  
pp. 685-692 ◽  
Author(s):  
Michael T Nurmohamed ◽  
René J Berckmans ◽  
Willy M Morriën-Salomons ◽  
Fenny Berends ◽  
Daan W Hommes ◽  
...  
Keyword(s):  
Whole Blood ◽  
Partial Thromboplastin Time ◽  
Ex Vivo ◽  
Fold Increase ◽  
Heparin Therapy ◽  
Activated Partial Thromboplastin Time ◽  
Recombinant Hirudin ◽  
Interindividual Differences ◽  
The Relationship

SummaryBackground. Recombinant hirudin (RH) is a new anticoagulant for prophylaxis and treatment of venous and arterial thrombosis. To which extent the activated partial thromboplastin time (APTT) is suitable for monitoring of RH has not been properly evaluated. Recently, a capillary whole blood device was developed for bed-side monitoring of the APTT and it was demonstrated that this device was suitable to monitor heparin therapy. However, monitoring of RH was not evaluated.Study Objectives. To evaluate in vitro and ex vivo the responsiveness and reproducibility for hirudin monitoring of the whole blood monitor and of plasma APTT assays, which were performed with several reagents and two conventional coagulometers.Results. Large interindividual differences in hirudin responsiveness were noted in both the in vitro and the ex vivo experiments. The relationship between the APTT, expressed as clotting time or ratio of initial and prolonged APTT, and the hirudin concentration was nonlinear. A 1.5-fold increase of the clotting times was obtained at 150-200 ng/ml plasma. However, only a 2-fold increase was obtained at hirudin levels varying from 300 ng to more than 750 ng RH/ml plasma regardless of the assays. The relationship linearized upon logarithmic conversion of the ratio and the hirudin concentration. Disregarding the interindividual differences, and presuming full linearity of the relationship, all combinations were equally responsive to hirudin.Conclusions. All assays were equally responsive to hirudin. Levels up to 300 ng/ml plasma can be reliably estimated with each assay. The manual device may be preferable in situations where rapid availability of test results is necessary.

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