Facile Labeling of Sieve Element Phloem-Protein Bodies Using the Reciprocal Oligosaccharide Probe OGA 488

• Published in: Frontiers in plant science 2022, Vol.13, p.809923
• Main Authors: Azizpor, Pakeeza, Sullivan, Lucy, Lim, Aedric, Groover, Andrew
• Format: Article
• Language: English
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2022.809923

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 labeling and visualization methods. Here, we show that a reciprocal oligosaccharide probe, OGA , can be used in rapid and sensitive labeling of P-protein bodies in Arabidopsis, poplar, snap bean and cucumber in histological sections. OGA labeling of knockouts of the two Arabidopsis P-protein-encoding genes, and , indicated that labeling is specific to AtSEOR2. That protein bodies were labeled and visible in knockouts indicates that heterodimerization of AtSEOR1 and AtSEOR2 may not be necessary for P-protein body formation. Double labeling with a previously characterized stain for P-proteins, sulphorhodamine 101, confirmed P-protein labeling and also higher specificity of OGA for P-proteins. OGA is thus robust and easily used to label P-proteins in histological sections of multiple angiosperm species.