The dynamics of cereal cyst nematode infection differ between susceptible and resistant barley cultivars and lead to changes in (1,3;1,4)‐β‐glucan levels and HvCslF gene transcript abundance

Abstract

SummaryHeterodera avenae (cereal cyst nematode, CCN) infects the roots of barley (Hordeum vulgare) forming syncytial feeding sites. In resistant host plants, relatively few females develop to maturity. Little is known about the physiological and biochemical changes induced during CCN infection.Responses to CCN infection were investigated in resistant (Rha2) and susceptible barley cultivars through histological, compositional and transcriptional analysis.Two phases were identified that influence CCN viability, including feeding site establishment and subsequent cyst maturation. Syncytial development progressed faster in the resistant cultivar Chebec than in the susceptible cultivar Skiff, and was accompanied by changes in cell wall polysaccharide abundance, particularly (1,3;1,4)-b-glucan. Transcriptional profiling identified several glycosyl transferase genes, including CELLULOSE SYNTHASE-LIKE F10 (HvCslF10), which may contribute to differences in polysaccharide abundance between resistant and susceptible cultivars.In barley, Rha2-mediated CCN resistance drives rapid deterioration of CCN feeding sites, specific changes in cell wall-related transcript abundance and changes in cell wall composition. During H. avenae infection, (1,3;1,4)-b-glucan may influence CCN feeding site development by limiting solute flow, similar to (1,3)-b-glucan during dicot cyst nematode infections. Dynamic transcriptional changes in uncharacterized HvCslF genes, possibly involved in (1,3;1,4)-b-glucan synthesis, suggest a role for these genes in the CCN infection process.

Differences in glycosyltransferase family 61 accompany variation in seed coat mucilage composition inPlantagospp.

“…GT61 family members have been implicated in the substitution of xylan polysaccharides in species such as rice and wheat (Anders et al , 2012; Chiniquy et al , 2012), and are therefore attractive candidates driving structural differences in heteroxylan identified between P. ovata and P. cunninghamii . A total of 18 GT61 contigs were identified in the P. ovata transcriptome of which nine were predominantly detected in the developing seed coat (Fig.…”

“…Identification of several monocot GT61 enzymes as β-(1,2)-xylosyltransferases or α-(1,3)-arabinosyltransferases (Anders et al , 2012; Chiniquy et al , 2012) suggests that GT61 family genes may contribute to different xylan structures identified between P. ovata and P. cunninghamii . Monocot species generally contain more GT61 genes than eudicots, congruent with monocot xylan being heavily substituted with arabinosyl residues (Anders et al , 2012), while eudicot species typically contain xylan substituted with glucuronic acid mediated by GT8 enzymes (Scheller and Ulvskov, 2010).…”

“…An approximate maximum likelihood phylogenetic tree was constructed using the FastTree plugin (Price et al , 2010) in Geneious Pro version 8.1.3. Coding sequences of GT61 genes in Arabidopsis were extracted from Phytozome ® (Goodstein et al , 2012; ) using Pfam ID PF04577 published in Anders et al (2012), as well as the GT61 gene entries in CAZy (Lombard et al , 2014). …”

“…Specific GTs that catalyse the addition of variable sidechains onto the backbone are also of interest, particularly from an applied perspective, because they play an important role in polysaccharide solubility and viscosity. In Arabidopsis, the GUX GT8 proteins function as glucuronyltransferases (Lee et al , 2012) and in some cereal species, GT61 family members have been implicated in β-1,2-xylosyltransferase and/or α-1,3-arabinoxyltransferase activity (Anders et al , 2012; Chiniquy et al , 2012). A role for the GT61 family in seed mucilage has recently been shown in Arabidopsis, where the MUCI21 gene influences mucilage organization, possibly through modification of small amounts of xylan (Voiniciuc et al , 2015 a ; Ralet et al , 2016).…”

A Rice Ca2+ Binding Protein Is Required for Tapetum Function and Pollen Formation

“…Observation of anther development by semithin section analysis, TEM, and callose staining were performed according to previous studies (Fu et al, 2014;Aditya et al, 2015). For callose immunolabeling, sections were first deparaffinated using xylene before labeling with anticallose antibody (Meikle et al, 1991).…”