Metal-induced stress in survivor plants following the end-Permian collapse of land ecosystems
Metal-induced stress in survivor plants following the end-Permian collapse of land ecosystems
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DOI：
10.1130/g48333.1
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发表时间：
2021-02-05
期刊：
影响因子：
5.8
通讯作者：
Tong, Jinnan
中科院分区：
文献类型：
--
作者：
Chu, Daoliang;Dal Corso, Jacopo;Tong, Jinnan
畸形孢子和花粉广泛存在于记录二叠纪-三叠纪大灭绝的沉积物中。这些畸形被认为是当时极端环境条件的结果，但诱变剂和事件的确切时间尚不清楚。我们研究了中国西南部二叠纪-三叠纪热带泥炭地序列中畸形孢子体的丰度和金属含量。我们发现石松属植物的孢子四分体(占所有孢子形体的19%)出现一个显著的峰值，随着铜和汞浓度的增加而超过主要陆地灭绝间隔，这标志着二叠纪巨型蕨类森林的丧失，野火活动的增加，以及煤层的消失。因此，在热带泥炭地，突变只影响幸存的植物。突变可能是由金属毒性引起的，与汞和铜负荷的增加有关，但本身并不是陆地危机的直接原因。沿海沉积物的含量以及中国西南部陆地部分频繁的野火(Chu等人，2020年；Dal Corso等人，2020年)。一些植被在热带二叠纪陆地生态系统崩溃后幸存下来，就像在西南部的中国所看到的那样，那里茂盛的二叠纪巨型蕨类主导的热带雨林被包含几乎单一种的石室植物种群的草本植物所取代(冯等人，2020年)。全球在PTME期间沉积的沉积物中观察到了孢子四分体和花粉畸形，并在
Teratological spores and pollen are widespread in sediments that record the PermianTriassic mass extinction. The malformations are thought to be the result of extreme environmental conditions at that time, but the mutagenic agents and the precise timing of the events remain unclear. We examined the abundance of teratological sporomorphs and metal concentrations in a Permian-Triassic tropical peatland succession of southwestern China. We find a significant peak of spore tetrads of lycopsid plants (as much as 19% of all sporomorphs) coeval with increases in Cu and Hg concentrations above the main terrestrial extinction interval, which marks the loss of Permian Gigantopteris forests, increased wildfire activity, and the disappearance of coal beds. Thus, in tropical peatlands, mutagenesis affected only surviving plants. Mutagenesis was likely caused by metal toxicity, linked to increased Hg and Cu loading, but was not itself a direct cause of the terrestrial crisis.content of coastal sediments, and frequent wildfires in terrestrial sections of southwestern China (Chu et al., 2020; Dal Corso et al., 2020). Some vegetation survived the collapse of the Permian terrestrial ecosystems in the tropics, as seen in southwestern China, where the luxuriant Permian Gigantopteris-dominated rainforests were replaced by herblands comprising almost monospecific lycophyte populations (Feng et al., 2020). Spore tetrads and pollen malformations have been observed globally in sediments deposited during the PTME and are commonly reported in