| Title | Metabolism-mediated induction of zinc tolerance in Brassica rapa by Burkholderia cepacia CS2-1 |
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| Author | Sang-Mo Kang1, Raheem Shahzad1, Saqib Bilal1, Abdul Latif Khan2, Young-Hyun You3, Won-Hee Lee1, Hee-La Ryu1, Ko-Eun Lee1, and In-Jung Lee1* |
| Address | 1School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea, 2Chair of Oman’s Medicinal Plants and Marine Natural Products, University of Nizwa, Nizwa 616, Oman, 3Microorganism Resources Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea |
| Bibliography | Journal of Microbiology, 55(12),955–965, 2017, |
| DOI | 10.1007/s12275-017-7305-7 |
| Key Words | plant growth-promoting rhizobacterium, zinc toxicity, amino acid, antioxidant, abscisic acid, salicylic acid |
| Abstract | Brassica rapa (Chinese cabbage) is an essential component of traditional Korean food. However, the crop is often subject to zinc (Zn+) toxicity from contaminated irrigation water, which, as a result, compromises plant growth and production, as well as the health of human consumers. The present study investigated the bioaccumulation of Zn+ by Burkholderia cepacia CS2-1 and its effect on the heavy metal tolerance of Chinese cabbage. Strain CS2-1 was identified and characterized on the basis of 16S rRNA sequences and phylogenetic analysis. The strain actively produced indole-3-acetic acid (3.08 ± 0.21 μg/ml) and was also able to produce siderophore, solubilize minerals, and tolerate various concentrations of Zn+. The heavy metal tolerance of B. rapa plants was enhanced by CS2-1 inoculation, as indicated by growth attributes, Zn+ uptake, amino acid synthesis, antioxidant levels, and endogenous hormone (ABA and SA) synthesis. Without inoculation, the application of Zn+ negatively affected the growth and physiology of B. rapa plants. However, CS2-1 inoculation improved plant growth, lowered Zn+ uptake, altered both amino acid regulation and levels of flavonoids and phenolics, and significantly decreased levels of superoxide dismutase, endogenous abscisic acid, and salicylic acid. These findings indicate that B. cepacia CS2-1 is suitable for bioremediation against Zn+-induced oxidative stress. |