Increasing the amylose content of durum wheat through silencing of the SBEIIagenes

BMC Plant Biology

Research Article

Angela Doherty¹  Huw D Jones¹  Stefania Masci²  Francesco Sestili²  Domenico Lafiandra²  Ermelinda Botticella²  Renato D'Ovidio²  Michela Janni² 

[1] Rothamsted Research, Department of Plant Science, Harpenden, UK;University of Tuscia, Department of Agrobiology & Agrochemistry, Viterbo, Italy;

关键词: Starch;    Amylose;    Durum Wheat;    Starch Granule;    Amylose Content;   

DOI  :  10.1186/1471-2229-10-144

 received in 2009-12-17, accepted in 2010-07-14,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundHigh amylose starch has attracted particular interest because of its correlation with the amount of Resistant Starch (RS) in food. RS plays a role similar to fibre with beneficial effects for human health, providing protection from several diseases such as colon cancer, diabetes, obesity, osteoporosis and cardiovascular diseases. Amylose content can be modified by a targeted manipulation of the starch biosynthetic pathway. In particular, the inactivation of the enzymes involved in amylopectin synthesis can lead to the increase of amylose content. In this work, genes encoding starch branching enzymes of class II (SBEIIa) were silenced using the RNA interference (RNAi) technique in two cultivars of durum wheat, using two different methods of transformation (biolistic and Agrobacterium). Expression of RNAi transcripts was targeted to the seed endosperm using a tissue-specific promoter.ResultsAmylose content was markedly increased in the durum wheat transgenic lines exhibiting SBEIIa gene silencing. Moreover the starch granules in these lines were deformed, possessing an irregular and deflated shape and being smaller than those present in the untransformed controls. Two novel granule bound proteins, identified by SDS-PAGE in SBEIIa RNAi lines, were investigated by mass spectrometry and shown to have strong homologies to the waxy proteins. RVA analysis showed new pasting properties associated with high amylose lines in comparison with untransformed controls. Finally, pleiotropic effects on other starch genes were found by semi-quantitative and Real-Time reverse transcription-polymerase chain reaction (RT-PCR).ConclusionWe have found that the silencing of SBEIIa genes in durum wheat causes obvious alterations in granule morphology and starch composition, leading to high amylose wheat. Results obtained with two different methods of transformation and in two durum wheat cultivars were comparable.

【 授权许可】

Unknown   
© Sestili et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.