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bioRxiv · 10.1101/2021.04.27.441549

Tryptophan derivatives regulate the seed germination and radicle growth of a root parasitic plant, Orobanche minor

Kuruma, M.·Suzuki, T.·Seto, Y.
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Abstract

Root parasitic plant germination is induced by the host-derived chemical, strigolactone (SL). We found that a major microbial culture broth component, tryptone, inhibits the SL-inducible germination of a root parasitic plant, Orobanche minor. O_SCPLOWLC_SCPLOW-tryptophan (1a, O_SCPLOWLC_SCPLOW-Trp) was isolated as the active compound from tryptone. We further found that O_SCPLOWLC_SCPLOW-Trp related compounds (1b-11), such as a major plant hormone auxin (8, indole-3-acetic acid; IAA), also inhibit the germination and post-radicle growth of O. minor. We designed a hybrid chemical (13), in which IAA is attached to a part of SL, and found that this synthetic analog induced the germination of O. minor, and also inhibited post-radicle growth. Moreover, we found that N-acetyl Trp (9) showed germination stimulating activity, and introduction of a substitution at C-5 position incresed its activity (12a-12f). Our data, in particular, the discovery of a structurally hybrid compound that has two activities that induce spontaneous germination and inhibit subsequent radical growth, would provide new types of germination regulators for root parasitic plants.

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Kuruma, M., Suzuki, T., Seto, Y.. 2021-04-27. Tryptophan derivatives regulate the seed germination and radicle growth of a root parasitic plant, Orobanche minor. https://doi.org/10.1101/2021.04.27.441549

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