Volatiles released by endophytic Pseudomonas fluorescens promoting the growth and volatile oil accumulation in Atractylodes lancea

• Published in: Plant physiology and biochemistry 2016-04, Vol.101, p.132-140
• Main Authors: Zhou, Jia-Yu, Li, Xia, Zheng, Jiao-Yan, Dai, Chuan-Chao
• Format: Article
• Language: English
• Subjects: Atractylodes - growth & development; Atractylodes - microbiology; Atractylodes lancea; Bacterial volatiles; Benzaldehydes - metabolism; Endophytic bacterium; Non-contact co-culture; Oils, Volatile - metabolism; Plant growth promotion; Pseudomonas fluorescens; Pseudomonas fluorescens - metabolism; Symbiosis - physiology; Volatile oil accumulation
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2016.01.026

Atractylodes lancea is a well-known, but endangered, Chinese medicinal plant whose volatile oils are its main active components. As the volatile oil content in cultivated A. lancea is much lower than that in the wild herb, the application of microbes or related elicitors to promote growth and volatile oil accumulation in the cultivated herb is an important area of research. This study demonstrates that the endophytic bacterium Pseudomonas fluorescens ALEB7B isolated from the geo-authentic A. lancea can release several nitrogenous volatiles, such as formamide and N,N-dimethyl-formamide, which significantly promote the growth of non-infected A. lancea. Moreover, the main bacterial volatile benzaldehyde significantly promotes volatile oil accumulation in non-infected A. lancea via activating plant defense responses. Notably, the bacterial nitrogenous volatiles cannot be detected in the A. lancea – Pseudomonas fluorescens symbiont while the benzaldehyde can be detected, indicating the nitrogenous volatiles or their precursors may have been consumed by the host plant. This study firstly demonstrates that the interaction between plant and endophytic bacterium is not limited to the commonly known physical contact, extending the ecological functions of endophyte in the phytosphere and deepening the understandings about the symbiotic interaction. •Volatiles from endophytic Pseudomonas fluorescens affect Atractylodes lancea.•Nitrogenous volatiles from P. fluorescens promote the plant growth.•Benzaldehyde from P. fluorescens promotes the plant volatile oil accumulations.•Benzaldehyde from P. fluorescens activates the plant defense responses.•Benzaldehyde can be detected in the A. lancea – P. fluorescens symbiont.