Symplasmic phloem loading and subcellular transport in storage roots are key factors for carbon allocation in cassava

Rüscher D, Vasina VV, Knoblauch J, Bellin L, Pommerrenig B, Alseekh S, Fernie AR, Neuhaus HE, Knoblauch M, Sonnewald U, Zierer W (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Plant Physiology American Society of Plant Biologists

Book Volume: 196

Pages Range: 1322-1339

Journal Issue: 2

DOI: 10.1093/plphys/kiae298

Abstract

Cassava (Manihot esculenta) is a deciduous woody perennial shrub that stores large amounts of carbon and water in its storage roots. Previous studies have shown that assimilating unloading into storage roots happens symplasmically once secondary anatomy is established. However, mechanisms controlling phloem loading and overall carbon partitioning to different cassava tissues remain unclear. Here, we used a combination of histological, transcriptional, and biochemical analyses on different cassava tissues and at different timepoints to better understand source–sink carbon allocation. We found that cassava likely utilizes a predominantly passive symplasmic phloem loading strategy, indicated by the lack of expression of genes coding for key players of sucrose transport, the existence of branched plasmodesmata in the companion cell/bundle sheath interface of minor leaf veins, and very high leaf sucrose concentrations. Furthermore, we showed that tissue-specific changes in anatomy and non-structural carbohydrate contents are associated with tissue-specific modification in gene expression for sucrose cleavage/synthesis, as well as subcellular compartmentalization of sugars. Overall, our data suggest that carbon allocation during storage root filling is mostly facilitated symplasmically and is likely mostly regulated by local tissue demand and subcellular compartmentalization.

Authors with CRIS profile

David Rüscher Lehrstuhl für Biochemie Uwe Sonnewald Lehrstuhl für Biochemie Wolfgang Zierer Lehrstuhl für Biochemie

Involved external institutions

Washington State University (WSU) US United States (USA) (US) Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau (RPTU) DE Germany (DE) Max-Planck-Institut für molekulare Pflanzenphysiologie / Max Planck Institute of Molecular Plant Physiology DE Germany (DE)

How to cite

APA:

Rüscher, D., Vasina, V.V., Knoblauch, J., Bellin, L., Pommerrenig, B., Alseekh, S.,... Zierer, W. (2024). Symplasmic phloem loading and subcellular transport in storage roots are key factors for carbon allocation in cassava. Plant Physiology, 196(2), 1322-1339. https://doi.org/10.1093/plphys/kiae298

MLA:

Rüscher, David, et al. "Symplasmic phloem loading and subcellular transport in storage roots are key factors for carbon allocation in cassava." Plant Physiology 196.2 (2024): 1322-1339.

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