标题：Cloning and characterization of acid invertase genes in the roots of the metallophyte Kummerowia stipulacea (Maxim.) Makino from two populations: Differential expression under copper stress

作者：Zhang, Luan; Xiong, Zhi-ting; Xu, Zhong-rui; Liu, Chen; Cai, Shen-wen

来源出版物：ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 卷：104 页：87-95 DOI：10.1016/j.ecoenv.2014.02.005 出版年：JUN 2014

摘要：The roots of metallophytes serve as the key interface between plants and heavy metal-contaminated underground environments. It is known that the roots of metallicolous plants show a higher activity of acid invertase enzymes than those of non-metallicolous plants when under copper stress. To test whether the higher activity of acid invertases is the result of increased expression of acid invertase genes or variations in the amino acid sequences between the two population types, we isolated full cDNAs for acid invertases from two populations of Kummerowia stipulacea (from metalliferous and non-metalliferous soils), determined their nucleotide sequences, expressed them in Pichia pastoris, and conducted real-time PCR to determine differences in transcript levels during Cu stress. Heterologous expression of acid invertase cDNAs in P. pastoris indicated that variations in the amino acid sequences of acid invertases between the two populations played no significant role in determining enzyme characteristics. Seedlings of K. stipulacea were exposed to 0.3 mu M Cu2+ (control) and 10 mu M Cu2+ for 7 days under hydroponics' conditions. The transcript levels of acid invertases in metallicolous plants were significantly higher than in non-metallicolous plants when under copper stress. The results suggest that the expression of acid invertase genes in metallicolous plants of K. stipulacea differed from those in non-metallicolous plants tinder such conditions. In addition, the sugars may play an important role in regulating the transcript level of acid invertase genes and acid invertase genes may also be involved in root/shoot biomass allocation.

入藏号：WOS:000336009700011

作者关键词：Cloning, Acid invertase, Copper, Sucrose, Kinetics parameters, Gene expression

扩展关键词：CELL-WALL INVERTASE; PLANT DEVELOPMENT; VACUOLAR INVERTASES; SWEET-POTATO; SUBSTRATE SPECIFICITIES; FRUCTAN 1-EXOHYDROLASE; MUTATIONAL ANALYSIS; SUCROSE METABOLISM; CU STRESS; SUBSTITUTION

标题：Physiological responses of biomass allocation, root architecture, and invertase activity to copper stress in young seedlings from two populations of Kummerowia stipulacea (maxim.) Makino

作者：Zhang, Luan; Pan, Yuxue; Lv, Wei; Xiong, Zhi-ting

来源出版物：ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY卷：104 页：278-284 DOI：10.1016/j.ecoenv.2014.03.013 出版年：JUN 2014

摘要：In the current study, we hypothesize that mine (metallicolous) populations of metallophytes form a trade-off between the roots and shoots when under copper (Cu) stress to adapt themselves to heavy metal contaminated habitats, and thus, differ from normal (non-metallicolous) populations in biomass allocation. To test the hypothesis, two populations of the metallophyte Kummerowia stipulacea, one from an ancient Cu mine (MP) and the other from a non-contaminated site (NMP), were treated with Cu2+ in hydroponic conditions. The results showed that MP plants had higher root/shoot biomass allocation and more complicated root system architecture compared to those of the NMP plants when under Cu stress. The net photosynthetic capacity was more inhibited in the NMP plants than in the MP plants when under Cu stress. The sugar (sucrose and hexose) contents and acid invertase activities of MP plants were elevated while those in NMP plants were inhibited after Cu treatment. The neutral/alkaline invertase activities and sucrose synthase level showed no significant differences between the two populations when under Cu stress. The results showed that acid invertase played an important role in biomass allocation and that the physiological responses were beneficial for the high root/shoot biomass allocation, which were advantageous during adaptive evolution to Cu-enriched mine soils.

入藏号：WOS:000336009700038

作者关键词：Kummerowia stipulacea, Biomass allocation, Photosynthesis, Sugar, Acid invertase, Root architecture

扩展关键词：SUCROSE-CLEAVING ENZYMES; HEAVY-METAL UPTAKE; PLANT DEVELOPMENT; SILENE-VULGARIS; CARBON ALLOCATION; GENE-EXPRESSION; USE EFFICIENCY; TOLERANCE; GROWTH; ROLES

通讯作者地址：Xiong, Zhi-ting; Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.

电子邮件地址：ztixong@whu.edu.cn

地址：

[Zhang, Luan; Pan, Yuxue; Lv, Wei; Xiong, Zhi-ting]Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.

研究方向：Environmental Sciences & Ecology; Toxicology

ISSN：0147-6513