Characterization of a novel GH26 β-mannanase from Paenibacillus polymyxa and its application in the production of mannooligosaccharides

Horizontally transferred glycoside hydrolase 26 may aid hemipteran insects in plant tissue digestion

“…The GH26 family proteins are known to metabolize carbohydrates present in plant cell walls, particularly mannans and galactomannans (Araki et al, 2000; Braithwaite et al, 1995; Gao et al, 2023; Okazaki et al, 2002; Taylor et al, 2005; Zhang et al, 2014), so we hypothesize that the HGT insect GH26s play a role in plant cell wall degradation. Thus, we expected them to be highly expressed in digestive tissues.…”

“…Thus, we propose that after HGT, GH26 was co-opted by insects to feed on their plant hosts more efficiently. Specifically, we predict that insect GH26s are important for digesting seed tissues because bacterial GH26s efficiently hydrolyze galactomannan-rich substances such as the endosperm of seeds (Bågenholm et al, 2019; Gao et al, 2023; Liu et al, 2020; Malgas et al, 2015; Patel et al, 2016; Sharma et al, 2022; von Freiesleben et al, 2019). This is consistent with our results as many of the taxa that retained GH26s feed on the seeds of plants, such as the seed bugs and many stink bugs (Corrêa-Ferreira and De Azevedo, 2002; Depieri and Panizzi, 2011; Feir and Beck, 1963).…”

“…There have been many instances of glycoside hydrolase genes being incorporated into the genomes of insects, fungi, and plants via HGT (Acuña et al, 2012; Da Lage et al, 2013; Kfoury et al, 2024; Kirsch et al, 2014; Pauchet and Heckel, 2013; Shelomi et al, 2014; Shen et al, 2003; Shin et al, 2023; Wheeler et al, 2013; Wybouw et al, 2016). In this study, we characterize an HGT event of a gene encoding for a glycoside hydrolase family 26 (GH26) protein, which are enzymes that break down carbohydrates present in plant cell walls, specifically mannans and galactomannans (Braithwaite et al, 1995; Gao et al, 2023; Patel et al, 2016; Zhang et al, 2014). Galactomannans are highly abundant in the endosperm of plant seeds, particularly in legumes, and functional characterizations of GH26 proteins in bacteria have shown that they efficiently hydrolyze locust bean gum and guar gum, both of which are galactomannan polysaccharides extracted from plant seeds (Bågenholm et al, 2019; Gao et al, 2023; Liu et al, 2020; Malgas et al, 2015; Patel et al, 2016; Sharma et al, 2022; von Freiesleben et al, 2019).…”

“…In this study, we characterize an HGT event of a gene encoding for a glycoside hydrolase family 26 (GH26) protein, which are enzymes that break down carbohydrates present in plant cell walls, specifically mannans and galactomannans (Braithwaite et al, 1995; Gao et al, 2023; Patel et al, 2016; Zhang et al, 2014). Galactomannans are highly abundant in the endosperm of plant seeds, particularly in legumes, and functional characterizations of GH26 proteins in bacteria have shown that they efficiently hydrolyze locust bean gum and guar gum, both of which are galactomannan polysaccharides extracted from plant seeds (Bågenholm et al, 2019; Gao et al, 2023; Liu et al, 2020; Malgas et al, 2015; Patel et al, 2016; Sharma et al, 2022; von Freiesleben et al, 2019). This HGT can be traced back to an ancestor of the Pentaomoidea and the Lygaeoidea, two subfamilies within the order Hemiptera that include agriculturally relevant crop pests such as the stink bugs.…”