Probing the plant growth-promoting and heavy metal tolerance characteristics of Bradyrhizobium japonicum CB1809
EUROPEAN JOURNAL OF SOIL BIOLOGY | ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER | Published : 2014
Bradyrhizobium japonicum strain CB1809 was recently identified as a plant growth-promoting rhizobacteria in high arsenic substrate. However, it is not known if B.japonicum has growth promoting properties in plant species other than its leguminous host or the bacterium's tolerance to arsenic and metals. Solution culture was used to test the response of sunflower (Helianthus annus L.) and wheat (Triticum aestivum L.) to B.japonicum inoculation under elevated arsenic. The resazurin assay was used to determine the tolerance of B.japonicum to bioavailable heavy metals in solution. Inoculated sunflower and wheat were more tolerant of arsenic than uninoculated treatments. Thus, the growth promoting..View full abstract
Thank you to Ms Zarinah Amin for technical assistance in Experiment 1, to Ms Lynne Clucas for arsenic analyses, Dr Aynsley Tizzard for advice on auxin measurement, Dr Jessica Ray for assistance with determining B. japonicum viability and to Dr Augustine Doronila for reviewing the manuscript and making a number of helpful suggestions. The donation of wheat seeds by Luisetti Seeds Ltd (Canterbury, New Zealand) and B. japonicum inoculum from New-Edge Microbials (Albury, Australia), is gratefully acknowledged. This research was funded by a School of Civil Environmental and Chemical Engineering, RMIT University seed grant and the Lincoln University Research Fund. The study sponsors had no role in study design; in the collection, analysis, and interpretation of data; in the writing of the report; nor in the decision to submit the paper for publication.