Prolamin proteins alteration in durum wheat by species of the genus Eurygaster and Aelia (Insecta, Hemiptera)

Abstract

Wheat bugs are widely distributed in various areas of Europe, Asia and North Africa. Species belonging to the genus Eurygaster and Aelia pierce wheat kernels affecting protein quality. The effects of these insects' feeding activity have been studied mainly in bread wheat (Triticum aestivum L.). This study provides information on the degradation of prolamin proteins (glutenins and gliadins) of bug-damaged durum wheat (Triticum turgidum L. var durum) in six cultivars grown in Sardinia (Italy). Samples of whole flour mixture of 70% sound wheat and 30% damaged wheat were hydrated and incubated at two temperatures (45 and 4°C), for different periods of time (0, 1 and 3 h). Glutenin and gliadin content was analysed using free zone capillary electrophoresis. The presence of bug-damaged kernels had influence on the quality of durum wheat proteins. Glutenins were rapidly degraded independently to incubation temperature. Gliadin degradation, however, took place with dependence on temperature and incubation time. Therefore glutenin degradation was possibly not due solely to the activity of proteolytic enzymes but also to some other as yet unknown factor linked to wheat bugs' feeding activity.Additional key words: gliadin, glutenin, protein quality, Triticum turgidum L. var durum, wheat bugs. ResumenAlteración de las prolaminas en trigo duro por especies del género Eurygaster y Aelia (Insecta, Hemiptera)Los chinches de los cereales tienen una amplia distribución en diversas áreas de Europa, Asia y Norte de África. Especies pertenecientes a los géneros Eurygaster y Aelia se alimentan picando los granos de trigo afectando a la calidad de las proteínas. Esta alteración se ha estudiado principalmente en trigo blando (Triticum aestivum L.). El presente estudio aporta información sobre la degradación de las prolaminas (gluteninas y gliadinas) del trigo duro (Triticum turgidum L. var durum) dañado por los chinches de los cereales en seis variedades cultivadas en Cerdeña (Italia). Muestras de harina integral, con un 70% de trigo sano y un 30% de trigo dañado se incubaron a dos temperaturas (45 y 4°C), y a diferentes tiempos (0, 1 y 3 h). El contenido de las gluteninas y gliadinas se analizó mediante electroforesis capilar zonal. La presencia de granos picados por los chinches de los cereales influyó en la calidad de las proteínas del trigo duro. Las gluteninas se degradaron rápidamente, con independencia de la temperatura de incubación. En cambio, la degradación de las gliadinas resultó ser dependiente de la temperatura y del tiempo. Ante estos resultados, cabe plantearse la posibilidad de que la degradación de las gluteninas no sea debida sólo a la actividad de las proteasas sino también a algún otro factor ligado a la actividad alimenticia de los chinches de los cereales, todavía por determinar.Palabras clave adicionales: calidad de las proteínas, chinches de los cereales, gliadinas, gluteninas, Triticum turgidum L. var durum.

Effects of Wheat Bug (Eurygasterspp. andAeliaspp.) Infestation in Preharvest Period on Wheat Technological Quality and Gluten Composition

“…In the case when the changes in the amount of gliadin subunits were accompanied with the increasing amount of total gliadins, these changes also resulted in extreme increase in Farinograph SD (Varieties 1–5). Obtained results indicated that more intensive wheat bug infestation rate might have been related to gradual decomposition of glutenins resulting in higher relative amount of glutenins of low molecular weights [ 33 ].…”

Wheat breeding for resistance to the Sunn pest (Eurygaster spp.): Does risk occur?

“…Kinaci, G. Ki naci, 2007) and for making pasta and other foods (Ozderen et al, 2008;Gaponov et al, 2009;Salis et al, 2010).…”

Population Density and Distribution of Wheat Bugs Infesting Durum Wheat in Sardinia, Italy

“…The economic importance of wheat bug damage is due to crop losses and/or quality loss of wheat (Kinaci and Kinaci 2004), semolina (Ozderen et al 2008; Köksel et al 2009; Salis et al 2010), or flour (Hariri et al 2000; Sivri et al 1999, 2004; Aja et al 2004; Vaccino et al 2006; Werteker and Kramreither 2008). The feeding activity of wheat bugs also heavily affects the germination percentage of wheat (Bin et al 2006).…”