AUTHOR=Azizpor Pakeeza , Sullivan Lucy , Lim Aedric , Groover Andrew 

TITLE=Facile Labeling of Sieve Element Phloem-Protein Bodies Using the Reciprocal Oligosaccharide Probe OGA488

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.809923

DOI=10.3389/fpls.2022.809923

ISSN=1664-462X

ABSTRACT=Sieve elements of many angiosperms contain structural phloem proteins (P-proteins) that can interact to create large P-protein bodies. P-protein bodies can occlude sieve plates upon injury but the range of functional and physiological roles of P-proteins remains uncertain, in part because of challenges in labelling and visualization methods. Here, we show that a reciprocal oligosaccharide probe, OGA488, can be used in rapid and sensitive labelling of P-protein bodies in Arabidopsis, poplar, snap bean and cucumber in histological sections. OGA488 labelling of knockouts of the two Arabidopsis P-protein-encoding genes, AtSEOR1 and AtSEOR2, indicated that labelling is specific to AtSEOR2. That protein bodies were labelled and visible in Atseor1 knockouts indicates that heterodimerization of AtSEOR1 and AtSEOR2 may not be necessary for P-protein body formation. Double labelling with a previously characterized stain for P-proteins, sulphorhodamine 101, confirmed P-protein labelling and also higher specificity of OGA488 for P-proteins. OGA488 is thus robust and easily used to label P-proteins in histological sections of multiple angiosperm species.