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bioRxiv · 10.1101/2020.05.01.071738

Uclacyanin proteins are required for lignified nanodomain formation within Casparian strips

Reyt, G.·Chao, Z.·Flis, P.·Castrillo, G.·Chao, D.-Y.·Salt, D. E.
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Abstract

Casparian strips (CS) are cell wall modifications of vascular plants restricting extracellular free diffusion into and out the vascular system. This barrier plays a critical role in controlling the acquisition of nutrients and water necessary for normal plant development. CS are formed by the precise deposition of a band of lignin approximately 2 m wide and 150 nm thick spanning the apoplastic space between adjacent endodermal cells. Here, we identified a copper-containing protein, Uclacyanin1 (UCC1) that is sub-compartmentalised within the CS. UCC1 forms a central CS nanodomain in comparison with other CS-located proteins that are found to be mainly accumulated at the periphery of the CS. We found that loss-of-function of two uclacyanins (UCC1 and UCC2) reduces lignification specifically in this central CS nanodomain, revealing a nano-compartmentalised machinery for lignin polymerisation. This lack of lignification leads to increased endodermal permeability, and consequently to a loss of mineral nutrient homeostasis.

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Reyt, G., Chao, Z., Flis, P., Castrillo, G., Chao, D.-Y., Salt, D. E.. 2020-05-03. Uclacyanin proteins are required for lignified nanodomain formation within Casparian strips. https://doi.org/10.1101/2020.05.01.071738

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