Molecular characterization and expression of a cDNA encoding copper/zinc superoxide dismutase from cultured cells of cassava (Manihot esculenta Crantz)

Abstract

A cDNA, mSOD1, encoding cytosolic copper/ zinc superoxide dismutase (CuZnSOD) was cloned and characterized from cell cultures of cassava (Manihot esculenta Crantz) which produce a high yield of SOD. mSOD1 encodes a 152-amino acid polypeptide with a pI value of 5.84. Southern analysis using an mSOD1-speci®c probe indicated that a single copy of the mSOD1 gene is present in the cassava genome. The mSOD1 gene is highly expressed in cultured cells, as well as in intact stems and tuberous roots. It is expressed at a low level in leaves and petioles. Transcripts of mSOD1 were not detected in nontuberous roots. Transcriptional level of mSOD1 reaches a high level at stationary phase, and then sharply decreases during further culture. In excised cassava leaves, the mSOD1 gene responded to various stresses in dierent ways. The stresses tested included changes in temperature and exposure to stress-inducing chemicals. Levels of mSOD1 transcript increased dramatically a few hours after heat stress at 37°C and showed a synergistic eect with wounding stress. Levels decreased in response to chilling stress at 4°C and showed an antagonistic eect with wounding stress. The gene was induced by abscisic acid, ethephon, NaCl, sucrose, and methyl viologen. These results indicate that the mSOD1 gene is involved in the response to oxidative stress induced by environmental change.

Molecular characterization and response to salt stress of mRNAs encoding cytosolic Cu/Zn superoxide dismutase and catalase from Bruguiera gymnorrhiza

“…Guan and Scandalios (1998) reported that one of two highly conserved Cu/Zn-SOD genes in Zea mays was regulated by ABA. While Lee et al (1999) showed that the cytosolic Cu/Zn-SOD gene of cassava was induced by wounding stress and application of MJ, which is a known mediator of wounding stress. These findings imply that expression of the cytosolic Cu/Zn-SOD gene is regulated in a species-specific manner.…”

Molecular cloning and expression analysis of a Cu/Zn SOD gene (BcCSD1) from Brassica campestris ssp. chinensis

“…The plant SOD gene has been cloned from corn (Cannon, White, & Scandalios, 1987), cassava (Lee, Kim, You, Kwon, & Kwak, 1999), rice (Wang, Wang, & Wang, 2007), evodia (Wu, Gao, Pan, Luo, & Zhang, 2011), camellia oleifera (Guo & Zhang, 2012), and been applied to improve the plant resistance in recent years. For example the tobacco overexpressing cytosolic Cu/Zn SOD was more tolerant to acute doses of ozone than the control (Pitcher & Zilinskas, 1996).…”

Purification and characterization of thermostable monomeric chloroplastic Cu/Zn superoxide dismutase from Chenopodium murale

“…SODs constitute the first line of defense against highly toxic superoxide radicals by converting superoxide to H 2 O 2 and molecular oxygen. SOD activity has been reported to increase in response to stress conditions such as high irradiance, low temperature (Mauro et al, 2005) drought and high temperature (Lee et al, 1999;Rhizhsky et al, 2002;Selote and KhannaChopra, 2006). In our studies also chloroplastic Cu/Zn SOD protein content and activity increased in response to high temperature, high light and in water stress recovered plants (Fig.…”