Project description:The aim of this study is to investigate whether the known mechanisms of hyperaccumulaion in Brassicaceae hyperaccumulators (Arabidopsis halleri and Noccaea caerulescens) are conserved among different hyperaccumulating species or if there exist unknown mechanismsin other metal hyperaccumulating species.The comparison of transcriptomes between hyperaccumulator Sedum plumbizincicola and non-hyperaccumulator S. alfredii (NHE) was performed by taking advantage of next-generation sequencing.The data suggested that increased active uptake, long-distance transport and efficient chelation of heavy metals might represent common mechanisms occurred in various hyperaccumulators. Moreover, we found that those genes showing constitutively higher expression in S. plumbizincicola shoots are significantly enriched in processes related to cell wall metabolism, including biosynthesis/modification of cellulose, lignin, pectin, glucan, and other cell wall related components.
Project description:The present study demonstrates the development of an Agrobacterium-mediated genetic transformation method for species of the Sedum genus, which includes the Cd/Zn hyperaccumulator Sedum plumbizincicola and the non-hyperaccumulating ecotype of S. alfredii. Multiple shoots were induced from stem nodes of two Sedum plants using Murashige and Skoog (MS) medium containing 0.1 mg/L cytokinin 6-benzyladenine (6-BA) and 1.0 mg/L auxin 1-naphthaleneacetic acid (NAA). The shoot primordia were used as direct targets for Agrobacterium infection. Selection on hygromycin was highly effective in generating Agrobacterium-transformed explants. This callus-free procedure allowed us to obtain transgenic plantlets after rooting hygromycin-resistant shoots on phytohormone-free MS medium containing the antibiotic. The presence and expression of the reporter genes gusA and GFP in transgenic plants were confirmed by a real-time polymerase chain reaction, histochemical GUS assays, and confocal microscopy. This reliable method for genetic transformation of Sedum plants will help us to understand gene functions and the molecular mechanisms underlying Cd hypertolerance and hyperaccumulation in these species.
