近日，PNAS刊登的一项研究报告"Underground leaves of Philcoxia trap and digest nematodes"说，一种巴西植物使用它的粘性地下叶片捕捉并消化线虫。
RafaelSilvaOliveira及其同事提出了一种假说，即Philcoxiaminensis这种植物可能是食肉的，因为它的形态和习性类似于其他食肉植物。这种植物仅见于巴西Cerrado地区的光照良好的低营养土壤，而且它的许多微小的粘性叶片位于它生长的浅层白沙表层的下面。为了确定Philcoxiaminensis是不是食肉的，这组科研人员分析了它是否能够消化和吸收来自它的粘性地下叶片捕捉的许多线虫的营养，这是一种此前未被描述过的捕捉策略。
这组作者为这种植物提供了用氮的稳定同位素氮15（15N）标记的线虫。被提供了线虫的叶片含有了显著数量的氮15，这表明这种植物消化并吸收了这些线虫。Philcoxiaminensis的叶片拥有类似于其他食肉植物的磷酸酶的活性，这提示这些线虫是直接由这种植物消化的，而不是被微生物分解的。这组作者报告说，Philcoxiaminensis通过它的专门的地下叶片捕捉、用酶消化并吸吸收来自线虫的氮。这组作者说，这些发现表明了在严峻环境下生长的植物如何进化出获得营养的多样化的机制。（生物谷Bioon.com）
doi:10.1073/pnas.1114199109
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Underground leaves of Philcoxia trap and digest nematodes
Caio G. Pereiraa, Daniela P. Almenarab, Carlos E. Winterb, Peter W. Fritschc, Hans Lambersd, and Rafael S. Oliveiraa,d,1
The recently described genus Philcoxia comprises three species restricted to well lit and low-nutrient soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of some carnivorous plants, along with recent observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. Here we report compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also document both a unique capturing strategy for carnivorous plants and a case of a plant that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered about the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the diversity of nutrient-acquisition mechanisms that have evolved in plants growing in severely nutrient-impoverished environments such as the Brazilian Cerrado, one of the world's 34 biodiversity hotspots.
