title: Antioxidant enzyme systems and the ascorbate-glutathione cycle as contributing factors to cadmium accumulation and tolerance in two oilseed rape cultivars (Brassica napus L.) under moderate cadmium stress.
abstract: Oilseed rape (Brassica napus L.) with high tolerance to cadmium (Cd) may be used in the phytoremediation of Cd-contaminated fields. However, the mechanisms responsible for Cd accumulation and tolerance in oilseed rape are still poorly understood. Here, we investigated the physiological and molecular processes involved in Cd tolerance of two oilseed rape cultivars with different Cd accumulation abilities. The total Cd accumulation in cultivar L351 was higher than cultivar L338, particularly with increasing concentrations of Cd exposure. L338 was a more pronounced Cd-sensitive cultivar than L351, while higher activities of antioxidant enzymes (CAT, APX, GR, DHAR) as well as higher contents of GSH and AsA were all observed in L351 under Cd treatments, especially at high levels. No differences were found in SOD activities between the two cultivars under the same Cd treatments, suggesting that SOD was not the key factor in relation to the differences of Cd tolerance and accumulation between them. Gene expression levels of BnFe-SOD, BnCAT, BnAPX, BcGR and BoDHAR in roots of L351 were relatively higher than that in L338 under Cd exposure as well as BnCAT and BcGR in leaves. It is concluded that antioxidant enzymes and the ascorbate-glutathione cycle play important roles in oilseed rape Cd accumulation and tolerance.
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Sun
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Qiling
authors.initials: Q
authors.lastname: Tan
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yafang
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Nie
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Qu
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zuoxin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Hubei Provincial Engineering Laboratory for New Fertilizers/Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: hucx@mail.hzau.edu.cn.
authors.forename: Chengxiao
authors.initials: C
authors.lastname: Hu
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism*; D001673:Biodegradation, Environmental; D029688:Brassica napus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D004785:Environmental Pollutants; D002104:Cadmium; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidant enzyme activities; Cd; Gene expression; Oxidative stress; Reactive oxygen species