TY - JOUR A1 - Yadav, Heena A1 - Dreher, Dorothée A1 - Athmer, Benedikt A1 - Porzel, Andrea A1 - Gavrin, Aleksandr A1 - Baldermann, Susanne A1 - Tissier, Alain A1 - Hause, Bettina T1 - Medicago TERPENE SYNTHASE 10 is involved in defense against an oomycete root pathogen JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - In nature, plants interact with numerous beneficial or pathogenic soil-borne microorganisms. Plants have developed various defense strategies to expel pathogenic microbes, some of which function soon after pathogen infection. We used Medicago truncatula and its oomycete pathogen Aphanomyces euteiches to elucidate early responses of the infected root. A. euteiches causes root rot disease in legumes and is a limiting factor in legume production. Transcript profiling of seedlings and adult plant roots inoculated with A. euteiches zoospores for 2 h revealed specific upregulation of a gene encoding a putative sesquiterpene synthase (M. truncatula TERPENE SYNTHASE 10 [MtTPS10]) in both developmental stages. MtTPS10 was specifically expressed in roots upon oomycete infection. Heterologous expression of MtTPS10 in yeast led to production of a blend of sesquiterpenes and sesquiterpene alcohols, with NMR identifying a major peak corresponding to himalachol. Moreover, plants carrying a tobacco (Nicotiana tabacum) retrotransposon Tnt1 insertion in MtTPS10 lacked the emission of sesquiterpenes upon A. euteiches infection, supporting the assumption that the identified gene encodes a multiproduct sesquiterpene synthase. Mttps10 plants and plants with reduced MtTPS10 transcript levels created by expression of an MtTPS10-artificial microRNA in roots were more susceptible to A. euteiches infection than were the corresponding wild-type plants and roots transformed with the empty vector, respectively. Sesquiterpenes produced by expression of MtTPS10 in yeast also inhibited mycelial growth and A. euteiches zoospore germination. These data suggest that sesquiterpene production in roots by MtTPS10 plays a previously unrecognized role in the defense response of M. truncatula against A. euteiches. Y1 - 2019 U6 - https://doi.org/10.1104/pp.19.00278 SN - 0032-0889 SN - 1532-2548 VL - 180 IS - 3 SP - 1598 EP - 1613 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Dreher, Dorothee A1 - Baldermann, Susanne A1 - Schreiner, Monika A1 - Hause, Bettina T1 - An arbuscular mycorrhizal fungus and a root pathogen induce different volatiles emitted by Medicago truncatula roots JF - Journal of Advanced Research N2 - Plants are in permanent contact with various microorganisms and are always impacted by them. To better understand the first steps of a plant’s recognition of soil-borne microorganisms, the early release of volatile organic compounds (VOCs) emitted from roots of Medicago truncatula in response to the symbiont Rhizophagus irregularis or the pathogenic oomycete Aphanomyces euteiches was analysed. More than 90 compounds were released from roots as detected by an untargeted gas chromatography-mass spectrometry approach. Principal component analyses clearly distinguished untreated roots from roots treated with either R. irregularis or A. euteiches. Several VOCs were found to be emitted specifically in response to each of the microorganisms. Limonene was specifically emitted from wild-type roots after contact with R. irregularis spores but not from roots of the mycorrhiza-deficient mutant does not make infections3. The application of limonene to mycorrhizal roots, however, did not affect the mycorrhization rate. Inoculation of roots with A. euteiches zoospores resulted in the specific emission of several sesquiterpenes, such as nerolidol, viridiflorol and nerolidol-epoxyacetate but application of nerolidol to zoospores of A. euteiches did not affect their vitality. Therefore, plants discriminate between different microorganisms at early stages of their interaction and respond differently to the level of root-emitted volatiles. KW - Arbuscular mycorrhiza KW - Oomycetous pathogen KW - Volatile organic compound (VOC) KW - Aeroponic cultivation KW - Gas chromatography-mass spectrometry (GC-MS) Y1 - 2019 U6 - https://doi.org/10.1016/j.jare.2019.03.002 SN - 2090-1232 SN - 2090-1224 VL - 19 SP - 85 EP - 90 PB - Elsevier CY - Amsterdam ER -