Neutralization of Bacterial YoeBSpn Toxicity and Enhanced Plant Growth in Arabidopsis thaliana via Co-Expression of the Toxin-Antitoxin Genes

• Published in: International journal of molecular sciences Vol. 17; no. 4; p. 321
• Main Authors: Abu Bakar, Fauziah, Yeo, Chew Chieng, Harikrishna, Jennifer Ann
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 20.04.2016; MDPI AG
• Subjects: 17-β-estradiol induction; Apoptosis - genetics; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis thaliana; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; bacterial toxin-antitoxin; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Green Fluorescent Proteins - analysis; heterologous expression; Plants, Genetically Modified - growth & development; Recombinant Fusion Proteins - analysis; Recombinant Fusion Proteins - genetics; YefM antitoxin; YoeB toxin; Arabidopsis thaliana; YefM antitoxin; bacterial toxin-antitoxin; heterologous expression; YoeB toxin; 17-β-estradiol induction
• ISSN: 1422-0067; 1422-0067
• DOI: 10.3390/ijms17040321

Bacterial toxin-antitoxin (TA) systems have various cellular functions, including as part of the general stress response. The genome of the Gram-positive human pathogen Streptococcus pneumoniae harbors several putative TA systems, including yefM-yoeBSpn, which is one of four systems that had been demonstrated to be biologically functional. Overexpression of the yoeBSpn toxin gene resulted in cell stasis and eventually cell death in its native host, as well as in Escherichia coli. Our previous work showed that induced expression of a yoeBSpn toxin-Green Fluorescent Protein (GFP) fusion gene apparently triggered apoptosis and was lethal in the model plant, Arabidopsis thaliana. In this study, we investigated the effects of co-expression of the yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic A. thaliana. When co-expressed in Arabidopsis, the YefMSpn antitoxin was found to neutralize the toxicity of YoeBSpn-GFP. Interestingly, the inducible expression of both yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic hybrid Arabidopsis resulted in larger rosette leaves and taller plants with a higher number of inflorescence stems and increased silique production. To our knowledge, this is the first demonstration of a prokaryotic antitoxin neutralizing its cognate toxin in plant cells.