Planta

, Volume 224, Issue 2, pp 268–278

Regulation of ethylene levels in canola (Brassica campestris) by 1-aminocyclopropane-1-carboxylate deaminase-containing Methylobacterium fujisawaense

Authors

  • Munusamy Madhaiyan
    • Department of Agricultural ChemistryChungbuk National University
  • Selvaraj Poonguzhali
    • Department of Agricultural ChemistryChungbuk National University
  • Jeounghyun Ryu
    • Department of Agricultural ChemistryChungbuk National University
    • Department of Agricultural ChemistryChungbuk National University
Original Article

DOI: 10.1007/s00425-005-0211-y

Cite this article as:
Madhaiyan, M., Poonguzhali, S., Ryu, J. et al. Planta (2006) 224: 268. doi:10.1007/s00425-005-0211-y

Abstract

We report the presence of ACC deaminase in Methylobacterium fujisawaense and its lowering of ethylene levels and promotion of root elongation in canola seedlings under gnotobiotic conditions. To test a part of the previous model proposed for ACC deaminase producing bacteria with Methylobacterium, ACC levels and various enzyme activities were monitored in canola. Lower amounts of ACC were present in the tissues of seeds treated with M. fujisawaense strains than in control seeds treated with MgSO4. Though the increased activities of ACC synthase in the tissue extracts of the treated seedlings might be due to bacterial indole-3-acetic acid, the amount of ACC was reduced due to bacterial ACC deaminase activity. The activities of ACC oxidase, the enzyme catalyzing conversion of ACC to ethylene remained lower in M. fujisawaense treated seedlings. This consequently lowered the ethylene in plants and prevented ethylene inhibition of root elongation. Our results collectively suggest that Methylobacterium commonly found in soils, as well as on the surfaces of leaves, seeds, and in the rhizosphere of a wide variety of plants could be better exploited to promote plant growth.

Keywords

ACC deaminaseEthyleneIndole acetic acidMethylobacterium

Abbreviations

ACC

1-aminocyclopropane-1-carboxylate

ACO

ACC oxidase

ACS

ACC synthase

AMS

Ammonium mineral salts

AVG

l-α-(2-aminoethoxyvinyl) glycine hydrochloride

CFU

Colony-forming units

IAA

Indole-3-acetic acid

iPA

Isopentenyladenosine

MTA

5′-methylthioadenosine

PGPR

Plant growth promoting rhizobacteria

PLP

Pyridoxal phosphate

PPFMs

Pink-pigmented facultative methylotrophic bacteria

PVPP

Polyvinylpolypyrrolidone

SAM

S-adenosyl methionine

t-ZR

trans-Zeatin riboside

Copyright information

© Springer-Verlag 2005