Expression of putative expansin genes in phylloxera (Daktulosphaira vitifoliae Fitch) induced root galls of Vitis spp.

Abstract

Grape phylloxera (Daktulosphaira vitifoliae Fitch) is a serious global pest in viticulture. The insects are sedentary feeders and require a gall to feed and reproduce. The insects induce their feeding site within the meristematic zone of the root tip, where they stay attached, feeding both intra- and intercellularly, and causing damage by reducing plant vigour. Several changes in cell structure and composition, including increased cell division and tissue swelling close to the feeding site, cause an organoid gall called a nodosity to develop. Because alpha expansin genes are involved in cell enlargement and cell wall loosening in many plant tissues it may be anticipated that they are also involved in nodosity formation. To identify expansin genes in Vitis vinifera cv. Pinot noir, we mined for orthologues genes in a comparative analysis. Eleven putative expansin genes were identified and shown to be present in the rootstock Teleki 5C (V. berlandieri Planch. x V. riparia Michx.) using specific PCR followed by DNA sequencing. Expression analysis of young and mature nodosities and uninfested root tips were conducted via quantitative real time PCR (qRT-PCR). Up-regulation was measured for three putative expansin genes (VvEXPA15, -A17 and partly -A20) or down-regulation for three other putative genes (VvEXPA7, -A12, -A20) in nodosities. The present study clearly shows the involvement of putative expansin genes in the phylloxera–root interaction.Electronic supplementary materialThe online version of this article (doi:10.1007/s10658-013-0173-z) contains supplementary material, which is available to authorized users.

Phylloxera (Daktulosphaira vitifoliae Fitch) alters the carbohydrate metabolism in root galls to allowing the compatible interaction with grapevine (Vitis ssp.) roots

“…Samples were sampled 1, 3 or 7 dai at mid-photoperiod. Gene expression analyses were performed in four biological replicates per treatment [39] . RNA was isolated according to RNeasy Plant Mini Kit protocol (Qiagen, Hilden, Germany), which was supplemented with an additional step for DNA digestion (RNase-Free DNase Set, Qiagen, Hilden, Germany).…”

Plant expansins: diversity and interactions with plant cell walls

“…Recent examples include the diverse expression of EXPB genes in soybean, particularly during Rhizobium infection and mycorrhiza associations [53], the expression of expansin genes in the wheat peduncle with modulation by Rht alleles for dwarfism, the involvement of multiple expansin genes in Arabidopsis leaf growth [54], and the complex regulation of expansin gene expression in grape during berry ripening and during phylloxera-induced gall formation [17,55]. Building on earlier studies (reviewed in [56]), recent work has also documented expression of specific expansin genes in response to various hormones [57–60].…”

Comparative Transcriptome Analysis of Two Root-Feeding Grape Phylloxera (D. vitifoliae) Lineages Feeding on a Rootstock and V. vinifera

“…Although aphids and grape phylloxera share a similar piercing-sucking feeding behavior, grape phylloxera larvae do not directly puncture phloem vessels but depend on redirecting flow from the phloem and accompanying cells towards the feeding site. Modifications of the cellular structure of phylloxerated roots have been shown to affect the expression levels of different expansins [ 37 ] and modifying the cell wall structure to enforce symplastic transfer [ 13 ]. The release of calmodulins and calreticulins by grape phylloxera, as presumed by this and other studies [ 42 , 44 ], may likely play an important role for the apo- and symplastic intercellular transport in order to ensure the uptake of nutrients from the surrounding root cell tissue or to maintain a certain influx pressure gradient towards the sucrose-importing phloem tissues.…”

“…Although the morphological modifications during grape phylloxera root gall formation are comparably well studied [ 8 , 9 , 13 , 16 , 17 , 24 , 35 , 36 , 37 ], the underlying biomolecular basis of root-feeding grape phylloxera biotypes is far from clear. Work employing molecular markers failed to identify biomarkers linked to host preference, e.g., [ 25 , 28 , 38 , 39 ] other than leaf feeding in native habitats.…”