Low cadmium (LCD), a novel gene related to cadmium tolerance and accumulation in rice

Abstract

The contamination of food crops by cadmium (Cd) is a major concern in food production because it can reduce crop yields and threaten human health. In this study, knockout rice plants (Oryza sativa) tagged with the gene trap vector pGA2707 were screened for Cd tolerance, and the tolerant line lcd was obtained. The lcd mutant showed tolerance to Cd on agar plates and in hydroponic culture during early plant development. Metal concentration measurements in hydroponically grown plants revealed significantly less Cd in the shoots of lcd plants compared with wild-type (WT) shoots. When cultured in the field in soil artificially contaminated with low levels of Cd, lcd showed no significant difference in the Cd content of its leaf blades; however, the Cd concentration in the grains was 55% lower in 2009 and 43% lower in 2010. There were no significant differences in plant dry weight or seed yield between lcd and wild-type plants. LCD, a novel gene, is not homologous to any other known gene. LCD localized to the cytoplasm and nucleus, and was expressed mainly in the vascular tissues in the roots and phloem companion cells in the leaves. These data indicate that lcd may be useful for understanding Cd transport mechanisms and is a promising candidate rice line for use in combating the threat of Cd to human health.

Uptake and Accumulation of Cadmium and Relative Gene Expression in Roots of Cd-resistant Salix matsudana Koidz

“…[36][37][38]. The current studies have shown Cd transport in rice, tomato, tobacco, and radish by ZIP1 [16,32,[39][40]. In the present investigation, expression of ZIP1 increased significantly and quickly in the roots of S. matsudana for the early stage of 50 μM Cd treatments (Fig.…”

Genome-wide identification and characterization of cadmium-responsive microRNAs and their target genes in radish (Raphanus sativus L.) roots

“…rsa-miR156 targeted a transcript encoding a glutathione S -transferase 5 ( GST5 ), whereas rsa-miR393 targeted phytochelatin synthase 1 ( PCS1 ). In plant cells, one major mechanism related to Cd detoxification is complexation with a range of metal-chelating peptides such as glutathione (GSH) and phytochelatins (PCs), both of which reduced its mobility and sequestered the phytochelatin–metal complexes into the vacuole (Shimo et al ., 2011; Satoh-Nagasawa et al ., 2012). Moreover, detoxification of reactive oxygen species (ROS) could be accomplished by synthesis of various antioxidants such as ascorbate, GSH, and glutathione S-transferase (DalCorso et al ., 2008; Takahashi et al ., 2011).…”

Mapping of Quantitative Trait Loci Associated with Concentrations of Five Trace Metal Elements in Rice (Oryza sativa)

“…The OsNRAMP5, OsHMA3, OsHMA2, OsLCT1 and LCD regulated the uptake, transport and accumulation of Cd in rice (Ueno et al, 2010;Shimo et al, 2011;Uraguchi et al, 2011;Ishimaru et al, 2012;Sasaki et al, 2012;SatohNagasawa et al, 2012;Takahashi et al, 2012). The OsNRAMP1, OsFER2, OsYSL2, OsYSL15, OsYSL18, OsIRT1 and OsIRT2 contributed to transporting of Fe in rice (Curie et al, 2000;Bughio et al, 2002;Koike et al, 2004;Ishimaru et al, 2006;Nakanishi et al, 2006;Inoue et al, 2009;Aoyama et al, 2009;Takahashi et al, 2011;Paul et al, 2012).…”