[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the prote...[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the protein encoded by this gene. [Method] Metagenomic DNA libraries of halophiles from the Dagong Ancient Brine Well were used for screening genes with Na＋/H＋ antiporter activity in antiporter-defi- cient E. coil KNabc strain by functional complementation. Then the start codon, stop codon, ORF, -35 region, -10 region and SD sequence of Na~/H＋ antiporter gene, as well as the molecular weight, isoelectric point, hydrophobic region, transmembrane domain, phyletic evolution and salt resistance of protein encoded by the gene were investigated. [Result] A new Na＋/H＋ antiporter gene m-nha was obtained, which ,ren- dered the antiporter-negative mutant E. coil KNabc cells with both the resistance to Na＋ and the ability to grow under alkaline conditions. [Conclusion] The structure and amino acid sequence of M-Nha was different from the previously reported Na＋/H~ antiporters, and the m-nha gene disclosed from the Dagong Ancient Brine Well was identified as a novel Na＋/H＋ antiporter gene. This study was significant not only in helping us understand the salt tolerance of halophiles in ancient brine wells and develop and utilize the genes resource, but also in exploring new salt-tolerant genes.展开更多
探讨‘泡桐1201’幼苗对盐胁迫的应答机制,为选育耐盐碱性作物,大力推广该树种提供科学依据。以30 d ‘泡桐1201’幼苗为材料,设置5组不同浓度梯度的盐胁迫处理,分析幼苗生理状况,通过测定幼苗的株高和主根长,植株根、茎、叶的鲜质量和...探讨‘泡桐1201’幼苗对盐胁迫的应答机制,为选育耐盐碱性作物,大力推广该树种提供科学依据。以30 d ‘泡桐1201’幼苗为材料,设置5组不同浓度梯度的盐胁迫处理,分析幼苗生理状况,通过测定幼苗的株高和主根长,植株根、茎、叶的鲜质量和干质量,叶片的叶绿素质量分数,叶和根的超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、丙二醛(MDA)质量摩尔浓度、过氧化氢酶(CAT)活性以及根系Na^+、K^+、H^+和Ca^(2+)的流速等指标,分析其生理方面、抗氧化系统以及离子流方面对盐胁迫的响应。结果表明,随着盐胁迫浓度增加,‘泡桐1201’幼苗生长受到的抑制增强,根长、株高、鲜质量和干质量均逐渐下降,地上部和地下部生物量均呈下降趋势。SOD活性、POD活性和CAT活性均先升高后降低,SOD活性和CAT活性变化趋势一致,均在100 mmol·L^(-1)时达到最大值;叶绿素质量分数呈现逐渐减少趋势。随着盐胁迫浓度的增大,根系Na^+外排速率先增大后减小,在100 mmol·L^(-1)达到最大值,以此来维持植物细胞的离子平衡,降低盐胁迫对植物的危害。K^+流速均表现为外排,外排速率随着盐胁迫浓度增加而增大。H^+主要表现为内流,并且随着盐胁迫浓度的增加,内流速率先增加后减小。Ca^(2+)流速均表现为内流,并且随着盐胁迫浓度增大流速增大。盐胁迫导致‘泡桐1201’幼苗株高、主根长、根茎叶的干质量和鲜质量受到抑制;‘泡桐1201’幼苗在盐浓度为0～50 mmol·L^(-1)胁迫下能够正常生长,在200 mmol·L^(-1)甚至出现致死的情况。展开更多
In this paper, a comparative study of the XRD characterization and FTIR spectroscopic behavior of some M^ILn^IIITiO4 phases with M^I： Na, H, K and Ln^III, the trivalent lanthanides elements： Sm, Eu, Er and Yb is rep...In this paper, a comparative study of the XRD characterization and FTIR spectroscopic behavior of some M^ILn^IIITiO4 phases with M^I： Na, H, K and Ln^III, the trivalent lanthanides elements： Sm, Eu, Er and Yb is reported. The H and K- oxides were obtained by ion-exchange from NaLnTiO4. These ternary oxides belong to the K2NiF4 structural type, with the M^I and Ln^III cations distributed in an ordered way on the K-sub lattice. The FTIR spectra of the materials were analyzed by comparison with structurally related materials. A close relationship with the parent NaLnTiO4 was found.展开更多
基金Supported by Chunhui Plan of Ministry of Education(Z2010101)Open Fund of Food Biotechnology Key Laboratory of Sichuan Province(SZJJ2009-014)Scientific Research Foundation of Xihua University(000022)~~
文摘[Objective] This study aimed to screen an Na＋/H＋ antiporter gene from the halophiles colonizing in the Dagong Ancient Brine Well in Zigong City, China, and then analyze the gene structure and properties of the protein encoded by this gene. [Method] Metagenomic DNA libraries of halophiles from the Dagong Ancient Brine Well were used for screening genes with Na＋/H＋ antiporter activity in antiporter-defi- cient E. coil KNabc strain by functional complementation. Then the start codon, stop codon, ORF, -35 region, -10 region and SD sequence of Na~/H＋ antiporter gene, as well as the molecular weight, isoelectric point, hydrophobic region, transmembrane domain, phyletic evolution and salt resistance of protein encoded by the gene were investigated. [Result] A new Na＋/H＋ antiporter gene m-nha was obtained, which ,ren- dered the antiporter-negative mutant E. coil KNabc cells with both the resistance to Na＋ and the ability to grow under alkaline conditions. [Conclusion] The structure and amino acid sequence of M-Nha was different from the previously reported Na＋/H~ antiporters, and the m-nha gene disclosed from the Dagong Ancient Brine Well was identified as a novel Na＋/H＋ antiporter gene. This study was significant not only in helping us understand the salt tolerance of halophiles in ancient brine wells and develop and utilize the genes resource, but also in exploring new salt-tolerant genes.
文摘In this paper, a comparative study of the XRD characterization and FTIR spectroscopic behavior of some M^ILn^IIITiO4 phases with M^I： Na, H, K and Ln^III, the trivalent lanthanides elements： Sm, Eu, Er and Yb is reported. The H and K- oxides were obtained by ion-exchange from NaLnTiO4. These ternary oxides belong to the K2NiF4 structural type, with the M^I and Ln^III cations distributed in an ordered way on the K-sub lattice. The FTIR spectra of the materials were analyzed by comparison with structurally related materials. A close relationship with the parent NaLnTiO4 was found.
