Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots

Dóra Bernula, Péter Benkő, Nikolett Kaszler, Ildikó Domonkos, Ildikó Valkai, Réka Szőllősi, Györgyi Ferenc, Ferhan Ayaydin, Attila Fehér, Katalin Gémes

Research output: Contribution to journalArticle

Abstract

In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50% of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots.

Original languageEnglish
JournalPlant Cell, Tissue and Organ Culture
DOIs
Publication statusAccepted/In press - Jan 1 2019

Fingerprint

cytokinins
auxins
Arabidopsis
shoots
explants
seedlings
organogenesis
somatic embryogenesis
trichomes
hormones
root primordia
in vitro regeneration
shoot meristems
plant damage
cotyledons
plantlets
leaves
callus
transcription factors
mutants

Keywords

  • Arabidopsis thaliana
  • Auxin transport inhibition
  • Cytokinin
  • Root explant
  • Shoot regeneration
  • Somatic embryogenesis
  • Wounding

ASJC Scopus subject areas

  • Horticulture

Cite this

Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots. / Bernula, Dóra; Benkő, Péter; Kaszler, Nikolett; Domonkos, Ildikó; Valkai, Ildikó; Szőllősi, Réka; Ferenc, Györgyi; Ayaydin, Ferhan; Fehér, Attila; Gémes, Katalin.

In: Plant Cell, Tissue and Organ Culture, 01.01.2019.

Research output: Contribution to journalArticle

Bernula, Dóra ; Benkő, Péter ; Kaszler, Nikolett ; Domonkos, Ildikó ; Valkai, Ildikó ; Szőllősi, Réka ; Ferenc, Györgyi ; Ayaydin, Ferhan ; Fehér, Attila ; Gémes, Katalin. / Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots. In: Plant Cell, Tissue and Organ Culture. 2019.
@article{551603eeb4e94ec58e358c145073b07f,
title = "Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots",
abstract = "In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50{\%} of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots.",
keywords = "Arabidopsis thaliana, Auxin transport inhibition, Cytokinin, Root explant, Shoot regeneration, Somatic embryogenesis, Wounding",
author = "D{\'o}ra Bernula and P{\'e}ter Benkő and Nikolett Kaszler and Ildik{\'o} Domonkos and Ildik{\'o} Valkai and R{\'e}ka Szőllősi and Gy{\"o}rgyi Ferenc and Ferhan Ayaydin and Attila Feh{\'e}r and Katalin G{\'e}mes",
year = "2019",
month = "1",
day = "1",
doi = "10.1007/s11240-019-01730-3",
language = "English",
journal = "Plant Cell, Tissue and Organ Culture",
issn = "0167-6857",
publisher = "Springer Netherlands",

}

TY - JOUR

T1 - Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots

AU - Bernula, Dóra

AU - Benkő, Péter

AU - Kaszler, Nikolett

AU - Domonkos, Ildikó

AU - Valkai, Ildikó

AU - Szőllősi, Réka

AU - Ferenc, Györgyi

AU - Ayaydin, Ferhan

AU - Fehér, Attila

AU - Gémes, Katalin

PY - 2019/1/1

Y1 - 2019/1/1

N2 - In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50% of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots.

AB - In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50% of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots.

KW - Arabidopsis thaliana

KW - Auxin transport inhibition

KW - Cytokinin

KW - Root explant

KW - Shoot regeneration

KW - Somatic embryogenesis

KW - Wounding

UR - http://www.scopus.com/inward/record.url?scp=85074990682&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074990682&partnerID=8YFLogxK

U2 - 10.1007/s11240-019-01730-3

DO - 10.1007/s11240-019-01730-3

M3 - Article

AN - SCOPUS:85074990682

JO - Plant Cell, Tissue and Organ Culture

JF - Plant Cell, Tissue and Organ Culture

SN - 0167-6857

ER -