Investigation of Arabidopsis root skototropism with different distance settings

ABSTRACT

Plants can activate protective and defense mechanisms under biotic and abiotic stresses. Their roots naturally grow in the soil, but when they encounter sunlight in the top-soil layers, they may move away from the light source to seek darkness. Here we investigate the skototropic behavior of roots, which promotes their fitness and survival. Glutamate-like receptors (GLRs) of plants play roles in sensing and responding to signals, but their role in root skototropism is not yet understood. Light-induced tropisms are known to be affected by auxin distribution, mainly determined by auxin efflux proteins (PIN proteins) at the root tip. However, the role of PIN proteins in root skototropism has not been investigated yet. To better understand root skototropism and its connection to the distance between roots and light, we established five distance settings between seedlings and darkness to investigate the variations in root bending tendencies. We compared differences in root skototropic behavior across different expression lines of Arabidopsis thaliana seedlings (atglr3.7 ko, AtGLR3.7 OE, and pin2 knockout) to comprehend their functions. Our research shows that as the distance between roots and darkness increases, the root’s positive skototropism noticeably weakens. Our findings highlight the involvement of GLR3.7 and PIN2 in root skototropism.

KEYWORDS:

• Abiotic stress
• glutamate-like receptor
• PIN proteins
• root tropism
• light conditions

Acknowledgments

The authors acknowledge Stiftung Zukunft Jetzt! (Munich, Germany) for the scholarships to F.Y. All figures were created with BioRender.com.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Supplementary information. For, pre data supporting this study see Supplementary Data 1.

Author contributions

F.B. and F.Y. conceived and designed research studies; X.Y. and Y.L. performed the experiments, analyzed the data, and wrote the manuscript; F.Y. contributed to methodology and reviewed the manuscript; F.B. supervised the study and reviewed the manuscript.

Data availability statement

The authors declare that all relevant data supporting the findings of this study are available within the paper and its supplementary files. All data for the main figures are provided in Supplementary Data 1. All other data will be available from corresponding authors upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2024.2348917

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.