title: Genome expression profile analysis reveals important transcripts in maize roots responding to the stress of heavy metal Pb.
abstract: Lead (Pb) has become one of the most abundant heavy metal pollutants of the environment. With its large biomass, maize could be an important object for studying the phytoremediation of Pb-contaminated soil. In our previous research, we screened 19 inbred lines of maize for Pb concentration, and line 178 was identified to be a hyperaccumulator for Pb in both the roots and aboveground parts. To identify important genes and metabolic pathways related to Pb accumulation and tolerance, line 178 was underwent genome expression profile under Pb stress and a control (CK). A total of approximately 11 million cDNA tags were sequenced and 4 665 539 and 4 936 038 clean tags were obtained from the libraries of the test and CK, respectively. In comparison to CK, 2379 and 1832 genes were identified up- or downregulated, respectively, more than fivefolds under Pb stress. Interestingly, all the genes were related to cellular processes and signaling, information storage and processing or metabolism functions. Particularly, the genes involved in posttranslational modification, protein turnover and chaperones; signal transduction, carbohydrate transport and metabolism; and lipid transport and metabolism significantly changed under the treatment. In addition, seven pathways including ribosome, photosynthesis, and carbon fixation were affected significantly, with 118, 12, 34, 21, 18, 72 and 43 differentially expressed genes involved. The significant upregulation of the ribosome pathway may reveal an important secret for Pb tolerance of line 178. And the sharp increase of laccase transcripts and metal ion transporters were suggested to account in part for Pb hyperaccumulation in the line.
authors: Maize Research Institute of Sichuan Agricultural University, Ya'an, 625014, China.
authors: Yaou
authors: Y
authors: Shen
authors: Yongzhong
authors: Y
authors: Zhang
authors: Jie
authors: J
authors: Chen
authors: Haijian
authors: H
authors: Lin
authors: Maojun
authors: M
authors: Zhao
authors: Huanwei
authors: H
authors: Peng
authors: Li
authors: L
authors: Liu
authors: Guangsheng
authors: G
authors: Yuan
authors: Suzhi
authors: S
authors: Zhang
authors: Zhiming
authors: Z
authors: Zhang
authors: Guangtang
authors: G
authors: Pan
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D057486:Carbon Cycle; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015536:Down-Regulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D018745:Genome, Plant / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D007854:Lead / Q000378:metabolism / Q000494:pharmacology*; D058977:Molecular Sequence Annotation; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA; D012989:Soil Pollutants / Q000494:pharmacology; D013312:Stress, Physiological; D059467:Transcriptome; D015854:Up-Regulation; D003313:Zea mays / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D018749:RNA, Plant; D012989:Soil Pollutants; D007854:Lead