scholarly journals In VitroCulture Conditions andOeARFandOeH3Expressions Modulate Adventitious Root Formation fromOleaster(Olea europaeaL. subsp.europaeavar.sylvestris) Cuttings

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Adriana Chiappetta ◽  
Cinzia Gagliardi ◽  
Leonardo Bruno ◽  
Maria Beatrice Bitonti

Olea europaeaL. subsp.europaea var.sylvestris, also namedoleaster, is the wild form of olive and it is used as rootstock and pollen donor for many cultivated varieties. An efficient procedure forin vitropropagation of oleaster was established in this study. A zeatin concentration of 2.5 mg/L was effective to induce an appreciable vegetative growth. Also high rooting efficiency was obtained by using a short IBA pulse, followed by two different IBA concentrations in the culture medium. With the aim to enlarge knowledge on the molecular aspects of adventitious rooting, we also evaluated the transcriptional modulation of anARFsmember andHISTONE H3genes, involved in auxin signaling and cell replication, respectively, during the root induction phase of cuttings. The obtained results suggest that the selected genes, as markers of the induction phase, could be very useful for setting up efficient culture conditions along the rooting process, thus increasing micropropagation efficiency.

2020 ◽  
Vol 67 (1-2) ◽  
pp. 16-26
Author(s):  
I. Verstraeten ◽  
H. Buyle ◽  
S. Werbrouck ◽  
M.C. Van Labeke ◽  
D. Geelen

In vitro propagation of the ornamentally interesting species Wikstroemia gemmata is limited by the recalcitrance to form adventitious roots. In this article, two strategies to improve the rooting capacity of in vitro microcuttings are presented. Firstly, the effect of exogenous auxin was evaluated in both light and dark cultivated stem segments and also the sucrose-content of the medium was varied in order to determine better rooting conditions. Secondly, different spectral lights were evaluated and the effect on shoot growth and root induction demonstrated that the exact spectral composition of light is important for successful in vitro growth and development of Wikstroemia gemmata. We show that exogenous auxin cannot compensate for the poor rooting under unfavorable light conditions. Adapting the culture conditions is therefore paramount for successful industrial propagation of Wikstroemia gemmata.


2019 ◽  
Author(s):  
Changzheng Xu ◽  
Yuanxun Tao ◽  
Xiaokang Fu ◽  
Li Guo ◽  
Haitao Xing ◽  
...  

AbstractAdventitious root (AR) formation at the base of stem cuttings determines the efficiency of clonal propagation for woody plants. Many endogenous and environmental factors influence AR formation. However, our knowledge about the regulation of AR development by mitochondrial metabolism in plants is very limited. Here we identified Populus-specific miR476a as a novel regulator of wound-induced adventitious rooting via orchestrating mitochondrial homeostasis in poplar. MiR476a exhibited inducible expression during AR formation and directly targets several Restorer of Fertility like (RFL) genes encoding mitochondrion-localized pentatricopeptide repeat proteins. Genetic modification of miR476-RFL expression revealed the miR476/RFL-mediated dynamic regulation of mitochondrial homeostasis on AR formation in transgenic poplar. Furthermore, mitochondrial perturbation via exogenous chemical inhibitor validated that the miR476a/RFL-directed AR formation depended on mitochondrial regulation though modulating the auxin pathway. Our results established a miRNA-directed mitochondrion-auxin signaling cascade required for AR development, providing novel insights into the understanding of mitochondrial regulation on plant developmental plasticity.


2020 ◽  
Vol 67 (1-2) ◽  
pp. 27-39 ◽  
Author(s):  
Alberto Pizarro ◽  
Carmen Díaz-Sala

Maturation-related decline of adventitious root formation is one of the major factors affecting adventitious rooting in forest tree species. We demonstrate that inhibition of polar auxin transport promoted cambium and xylem differentiation in rooting-competent hypocotyl cuttings from Pinus radiata under conditions of adventitious root formation. Treatments with bioactive gibberellins inhibited rooting while at the same time inducing both the differentiation of a continuous ring of cambium and xylem formation. Treatments with inhibitors of gibberellin biosynthesis did not affect the rooting response. The results demonstrate that xylem parenchyma and procambial cells at the xylem poles of rooting-competent hypocotyl cuttings after excision and under conditions of adventitious root induction become adventitious root meristems or xylem, depending on the directional auxin flow. Gibberellin may interact with this pathway, inducing xylem differentiation and inhibiting rooting. We conclude that modifications of auxin flow at the rooting sites, and the priming of cambial cells to differentiate into xylem during tree ageing, may be associated with the maturation-related decline of adventitious root formation.


1970 ◽  
Vol 35 (1) ◽  
pp. 135-142 ◽  
Author(s):  
MA Malek ◽  
D Khanam ◽  
M Khatun ◽  
MH Molla ◽  
MA Mannan

An experiment was conducted to study the in vitro culture of pointed gourd. Cotyledon rescued from physiologically matured seeds (PMS) and immatured seeds (IMS) of pointed gourd were used as explants. Cotyledon excised from PMS responded very well in all culture conditions. Plant regenerated from cotyledon of PMS ranged from 38 to 96% in different hormonal formulations of culture media. Highest percentage of shoot regeneration was observed in MS + 1.0 mg/l BAP and lowest in MS + 2.5 mg/l BAP. No plant regeneration was observed in cotyledon from immatured seeds. The highest percentage of root induction (99%) was achieved in half MS medium supplemented with 0.5 mg/l NAA. The regenerated plantlets were successfully established in earthen pot. Keywords: Cotyledon; in vitro; pointed gourd. DOI: 10.3329/bjar.v35i1.5874Bangladesh J. Agril. Res. 35(1) : 135-142, March 2010


2001 ◽  
Vol 7 (1) ◽  
Author(s):  
K. Magyar-Tábori ◽  
J. Dobránszky ◽  
E. Jámbor-Benczúr ◽  
J. Lazányi ◽  
J. Szalai

Rooting of in vitro 'Royal Gala' shoots was studied under different conditions of root induction and root elongation phase. The rooting capacity was affected by both rooting phases. Very high rooting percentage could be reached with both liquid and solid root induction media. Raising the temperature from 22 °C to 26 °C during root induction phase increased the rooting percentage. Presence of activated charcoal in root elongation media can affect the number of roots per rooted shoots and can increase the rooting percentage, the length of roots and the rate of survival depending also on other conditions during rooting. Presence of NAA in root elongation media reduced the number and the length of roots considerably. Favourable effect of activated charcoal on rooting was mainly due to adsorption of NAA.


2018 ◽  
Vol 28 (1) ◽  
pp. 69-76
Author(s):  
H Reshmi Singha ◽  
Sangram Sinha ◽  
Rabindra Kumar Sinha

An efficient method of clonal propagation through nodal culture of Solanum torvum Swartz. is described. Different concentrations of BAP/Kn alone or in combination with IAA were tested for direct shoot bud induction and proliferation. Lower concentration of BAP/Kn alone produced better shoot proliferation and elongation. Maximum number of shoot proliferation was achieved from MS supplemented with Kn 0.5 mg/l with an average 4.0 ± 1.41 shoots during 28 days of culture. Addition of IAA to the culture media in combination with BAP/ Kn significantly reduced the number of shoot formation. Regenerated plants also produced roots during subsequent culture in the same media supplemented with BAP/Kn alone or in combination with IAA. The easy nature of in vitro rooting of S. torvum was recorded without any separate root induction phase. Regenerated plants were successfully transferred to the field condition. Clonal feature was cytologically confirmed through the study of mitotic metaphase chromosomes of regenerated plants which reveals 2n = 24 somatic chromosomes. Comparative karyomorphological details between the mother and regenerated plants of S. torvum revealed close similarity in their chromosomal complements and falls under the category of "1B" Stebbin’s symmetric index suggesting true to type nature of the regenerated plant.Plant Tissue Cult. & Biotech. 28(1): 69-76, 2018 (June)


2005 ◽  
Vol 35 (12) ◽  
pp. 2775-2780 ◽  
Author(s):  
Jaroslav Ďurkovič ◽  
Viliam Pichler ◽  
Alexander Lux

Cultures of the Formosan sweetgum (Liquidambar formosana Hance) were established from axillary buds of intact plants and from petiole segments of in vitro grown leaves. Petiole segments were generally slower than axillary buds to form multiple shoot cultures. Thidiazuron in combination with 6-benzylaminopurine produced on average up to 9.4 shoots per explant. Shoot elongation was significantly affected by the concentration of 6-benzylaminopurine, regardless of auxin addition to the medium. Adventitious rooting occurred up to 90%. An unexpected pattern of adventitious rhizogenesis was observed from the aerial parts of microshoots not in contact with the rooting medium, including leaf blades and petiole axils. In vitro adventitious root formation from the leaf blade was associated with parenchyma cells surrounding the main vein. The regenerated plants established ex vitro did not show any detectable morphological variation and no aerial roots were formed.


Author(s):  
Xu Li ◽  
Xiaozhao Xu ◽  
Fei Shen ◽  
Wei Li ◽  
Changpeng Qiu ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Micheale Yifter Weldemichael ◽  
Yemane Tsehaye Bayratsion ◽  
Desta Berhe Sbhatu ◽  
Girmay Gebresamuel Abraha ◽  
Hagos Mohammedseid Juhar ◽  
...  

This study was conducted to develop an efficient regeneration protocol used for sesame genetic transformation. Published regeneration methods using 6-benzylaminopurine (BAP), indol-3-butyric acid (IBA), and α-naphthaleneacetic acid (NAA) were used in this experiment. Cotyledon explants of 14 Ethiopian genotypes collected from Humera Agricultural Research Center (HuARC) were used. Optimized culture conditions were used to investigate the regeneration response of different genotypes. Significant interactions between hormone treatments, MS media, and genotypes for shoot and root regeneration were recorded. Results showed that culture of cotyledons were developed and used as a source of explants for shoot regeneration. The highest shoot number, leaf number, and shoot length were recorded on explants cultured on 1.00 mg·L−1 BAP + 1.00 mg·L−1 NAA in Hirhir and Aberghele, 0.75 mg·L−1 BAP + 1.00 mg·L−1 NAA in Baha Zeyit, and 1.0 mg·L−1 BAP + 1.00 mg·L−1 NAA in Humera 1, respectively. The lowest shoot number, leaf number, and shoot length were observed on explants cultured on the control in Gondar 1, Borkana, and Baha Necho, Borkana and Beha Necho, and Baha Necho, respectively. Genotypes with well-developed shoots were transferred to root induction media. Under rooting media, the best mean, root number, and root length were observed in Aberghele and ACC44 at 0.1 mg·L−1 IBA and 0.2 mg·L−1 NAA, respectively. Standardizing genotypes trait data to mean 0 and unity variance has helped to group 14 genotypes into four distinct clusters. Hirhir, Abeghele, Baha Zeyit, and Humera 1 were the best genotypes. These findings lay ground to Ethiopian sesame to do further genetic transformation aiming at improving the crop.


2011 ◽  
Vol 39 (1) ◽  
pp. 307 ◽  
Author(s):  
Tiberia I. POP ◽  
Doru PAMFIL ◽  
Catherine BELLINI

Adventitious rooting is a complex process and a key step in the vegetative propagation of economically important woody, horticultural and agricultural species, playing an important role in the successful production of elite clones. The formation of adventitious roots is a quantitative genetic trait regulated by both environmental and endogenous factors. Among phytohormones, auxin plays an essential role in regulating roots development and it has been shown to be intimately involved in the process of adventitious rooting. Great progress has been made in elucidating the auxin-induced genes and auxin signaling pathway, especially in auxin response Aux/IAA and Auxin Response Factor gene families. Although some important aspects of adventitious and lateral rooting signaling have been revealed, the intricate signaling network remains poorly understood. This review summarizes some of the current knowledge on the physiological aspects of adventitious root formation and highlights the recent progress made in the identification of putative molecular players involved in the control of adventitious rooting. Despite much has been discovered regarding the effects and regulation of auxins on plant growth since the Darwin experiments, there is much that remains unknown.


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