Gene Expression Patterns for Proteins With Lectin Domains in Flax Stem Tissues Are Related to Deposition of Distinct Cell Wall Types.

Natalia Petrova,Oleg Gorshkov,Alsu Nazipova,Olga Patova,Tatyana Gorshkova,Natalia Mokshina

doi:10.3389/fpls.2021.634594

Abstract

The genomes of higher plants encode a variety of proteins with lectin domains that are able to specifically recognize certain carbohydrates. Plants are enriched in a variety of potentially complementary glycans, many of which are located in the cell wall. We performed a genome-wide search for flax proteins with lectin domains and compared the expression of the encoding genes in different stem tissues that have distinct cell wall types with different sets of major polysaccharides. Over 400 genes encoding proteins with lectin domains that belong to different families were revealed in the flax genome; three quarters of these genes were expressed in stem tissues. Hierarchical clustering of the data for all expressed lectins grouped the analyzed samples according to their characteristic cell wall type. Most lectins differentially expressed in tissues with primary, secondary, and tertiary cell walls were predicted to localize at the plasma membrane or cell wall. These lectins were from different families and had various architectural types. Three out of four flax genes for proteins with jacalin-like domains were highly upregulated in bast fibers at the stage of tertiary cell wall deposition. The dynamic changes in transcript level of many genes for lectins from various families were detected in stem tissue over the course of gravitropic response induced by plant gravistimulation. The data obtained in this study indicate a large number of lectin-mediated events in plants and provide insight into the proteins that take part in tissue specialization and reaction to abiotic stress.

Highlights

The term lectins joins a number of protein families capable of selectively recognizing various types of carbohydrates, while not interacting enzymatically with the recognized targets (Peumans and Van Damme, 1995)
The total number of lectin genes in the flax genome, over 400 genes, is among the highest described for a plant species (Van Holle et al, 2017)
The proportion of the number of genes in different lectin families is similar to that described in the literature for other higher plant species (Jiang et al, 2010; Bellande et al, 2017; Van Holle et al, 2017)

Summary

Introduction

The term lectins joins a number of protein families capable of selectively recognizing various types of carbohydrates, while not interacting enzymatically with the recognized targets (Peumans and Van Damme, 1995). Lectins are widespread and present in all biological kingdoms (Sharon, 2008; Tsaneva and Van Damme, 2020). It has been shown that not all lectins found during sequencing of plant genomes exhibit the property of agglutination (Van Damme et al, 2008). The genomes of higher plants encode a variety of lectin proteins, which are classified into families according to their conserved carbohydrate-recognition domains (Van Damme et al, 2008; Jiang et al, 2010). Sequence bioinformatics studies across all available databases have shown that some of the lectin motifs are widespread (from plants to animals, fungi, and bacteria), while others are present only in certain plant families. Several informative papers with generalizations on plant lectin families have been published (Bellande et al, 2017; Van Holle et al, 2017; Tsaneva and Van Damme, 2020)

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