Identification and functional analysis of an autophagy-related gene TdAtg8 in wild emmer wheat under biotic (fusarium culmorum) and abiotic (drought) stress conditions
Kuzuoğlu, Duygu (2010) Identification and functional analysis of an autophagy-related gene TdAtg8 in wild emmer wheat under biotic (fusarium culmorum) and abiotic (drought) stress conditions. [Thesis]
Official URL: http://192.168.1.20/record=b1305899 (Table of Contents)
Autophagy, literally self eating, is an evolutionary conserved catalytic process for vacuolar degradation of intracellular components, previously examined in yeast, mammals and plants. Abiotic stress factors, including nutrient starvation, oxidative stress, salt stress and osmotic stress have been previously reported to induce autophagy in plants. In this study, for the first time, Atg8 gene was cloned from wild emmer wheat (TdAtg8) and the role of autophagy under biotic and abiotic stress conditions was investigated. Examination of TdAtg8 expression patterns indicates that Atg8 expression was immensely upregulated under drought stress, especially in the roots. Monodansylcadaverine (MDC) and Lysotracker Red markers utilized to observe autophagosomes revealed that autophagy is constitutively active in T. dicoccoides. Moreover, autophagy was determined to be more active in plants exposed to drought stress when compared to plants grown under normal conditions. TdAtg8 gene was demonstrated to complement Atg8 yeast mutants grown under starvation conditions in a drop test assay. For further functional analysis, ATG8 protein from T. dicoccoides were expressed in yeast and analyzed with western blotting. TdAtg8 was also silenced in wild emmer wheat by virus-induced gene silencing and its role was investigated in the presence of a plant pathogen, Fusarium culmorum. This response, for the first time, showed that fungi sporulation decreased in Atg8 silenced plants in comparison to controls. Based on the data obtained, we conclude that the plants become more resistant against the plant pathogen when the autophagy was inhibited.
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