Arsenic Hyperaccumulation in Gametophytes of Pteris vittata. A New Model System for Analysis of Arsenic Hyperaccumulation1
Arsenic Hyperaccumulation in Gametophytes of Pteris vittata. A New Model System for Analysis of Arsenic Hyperaccumulation1
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DOI：
10.1104/pp.104.044073
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发表时间：
2004-10
期刊：
影响因子：
7.4
通讯作者：
L. Gumaelius;Brett Lahner;D. Salt;J. Banks
中科院分区：
文献类型：
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作者：
L. Gumaelius;Brett Lahner;D. Salt;J. Banks
蕨类植物Pteris vittata的孢子体在其叶片中超积累砷（As），超过其干重的1%。植物对砷的超积累已被确定为一个有价值的性状，为开发一个实用的植物修复过程，从环境中去除这种潜在的有毒微量元素。然而，由于P.vittata的孢子体是一种生长缓慢的多年生植物，具有大的基因组，没有发达的遗传学工具，这是不理想的调查的基本机制，在植物中的砷超积累。然而，像其他同孢蕨类植物一样，P. vittata从亲本孢子体植物产生并释放大量的单倍体孢子，这些孢子在萌发时发育为自由生活的、自养的单倍体配子体，其由小的（占其干重的2.5%）As组成。这与配子体的相关nonaccumulating蕨类植物Ceratopteris richardii，甚至在低浓度（0.1毫米）死亡。有趣的是，与P.vittata和C.相比，相关的As积累者Pityrogramma calomelanos的配子体似乎耐受并积累As到中间水平。理查德。从佛罗里达不同地点收集的40个不同的P.vittata孢子体植物的配子体群体的分析也揭示了存在的自然变异的As耐受性，但没有积累。这样的意见应该打开大门，新的和强大的遗传工具的解剖的分子机制参与的超积累在P. vittata使用配子体作为一个容易操作的模型系统。
The sporophyte of the fern Pteris vittata is known to hyperaccumulate arsenic (As) in its fronds to >1% of its dry weight. Hyperaccumulation of As by plants has been identified as a valuable trait for the development of a practical phytoremediation processes for removal of this potentially toxic trace element from the environment. However, because the sporophyte of P. vittata is a slow growing perennial plant, with a large genome and no developed genetics tools, it is not ideal for investigations into the basic mechanisms underlying As hyperaccumulation in plants. However, like other homosporous ferns, P. vittata produces and releases abundant haploid spores from the parent sporophyte plant which upon germination develop as free-living, autotrophic haploid gametophyte consisting of a small (2.5% of their dry weight as As. This contrasts with gametophytes of the related nonaccumulating fern Ceratopteris richardii, which die at even low (0.1 mm) As concentrations. Interestingly, gametophytes of the related As accumulator Pityrogramma calomelanos appear to tolerate and accumulate As to intermediate levels compared to P. vittata and C. richardii. Analysis of gametophyte populations from 40 different P. vittata sporophyte plants collected at different sites in Florida also revealed the existence of natural variability in As tolerance but not accumulation. Such observations should open the door to the application of new and powerful genetic tools for the dissection of the molecular mechanisms involved in As hyperaccumulation in P. vittata using gametophytes as an easily manipulated model system.