Related Experiment Videos
Production of Tsr factor by Rhizobium meliloti
V Jain1, N Garg, H S Nainawatee
1Department of Chemistry and Biochemistry, Haryana Agricultural University, Hisar, India.
Abstract:
The root exudates of alfalfa (Medicago sativa) and mungbean (Vigna radiata) induced the Tsr (thick and short roots) factor production in Rhizobium meliloti. The factor caused a 30-40% reduction of root length in alfalfa seedlings. Pea root exudate had no Tsr induction activity. The flavonoid naringenin could replace the roots in inducing Tsr production. Naringenin-induced Tsr factor caused 70% shortening of main roots. The Tsr inducing property of naringenin was specific since quercetin and syringaldehyde had no such effect.
Insights
Alfalfa and mungbean root compounds trigger a thick and short roots (Tsr) factor in Rhizobium meliloti, significantly reducing root length. The flavonoid naringenin specifically induces this root-shortening factor.
Area of Science:
- Plant-microbe interactions
- Molecular biology
- Biochemistry
Background:
- Root exudates play a crucial role in signaling between plants and soil microbes.
- Rhizobium meliloti is a symbiotic bacterium that forms nitrogen-fixing nodules on legumes.
- Plant root development is influenced by various environmental and molecular signals.
Purpose of the Study:
- To investigate the effect of alfalfa and mungbean root exudates on Rhizobium meliloti.
- To identify compounds in root exudates that induce the thick and short roots (Tsr) factor.
- To characterize the specificity of Tsr factor induction by plant-derived compounds.
Main Methods:
- Treatment of Rhizobium meliloti with root exudates from alfalfa, mungbean, and pea.
- Assaying for the production of the Tsr factor in Rhizobium meliloti.
- Testing the effect of specific flavonoids, including naringenin, quercetin, and syringaldehyde, on Tsr factor induction.
- Measuring the impact of the Tsr factor on alfalfa seedling root length.
Main Results:
- Alfalfa and mungbean root exudates induced Tsr factor production in Rhizobium meliloti.
- The induced Tsr factor reduced alfalfa seedling root length by 30-40%.
- Pea root exudate did not induce Tsr factor production.
- The flavonoid naringenin specifically induced Tsr factor production, causing a 70% shortening of main roots, while quercetin and syringaldehyde did not.
- Naringenin's Tsr-inducing property was specific.
Conclusions:
- Specific compounds in alfalfa and mungbean root exudates, notably the flavonoid naringenin, induce a Tsr factor in Rhizobium meliloti.
- This Tsr factor significantly inhibits root elongation in susceptible plants like alfalfa.
- Naringenin acts as a specific signal molecule in plant-microbe communication, influencing root morphology.