AUTHOR=Xu Lingling , Lu Lingli , Lin Xianyong , Hu Yan 

TITLE=Cadmium armors the Cd hyperaccumulator Sedum alfredii against aphid attack

JOURNAL=Frontiers in Environmental Science

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2022.1036708

DOI=10.3389/fenvs.2022.1036708

ISSN=2296-665X

ABSTRACT=<p>The cadmium (Cd) hyperaccumulator <italic>Sedum alfredii</italic> has been identified to have great ability to accumulate &gt;100 ppm (dry weight) of Cd in its aboveground biomass. However, little attention has been paid to the possibility that <italic>S. alfredii</italic> may benefit from this trait. Here, we investigated the effect of Cd accumulation on the performance of the black bean aphid <italic>Aphis fabae</italic> in <italic>S. alfredii</italic>. The results showed that 6 weeks of Cd exposure prevented <italic>S. alfredii</italic> from being infested by aphids. In another experiment, <italic>S. alfredii</italic> was pretreated with 100 μmol⋅dm⁻³ CdCl<sub>2</sub> for 7 days. Prolonged Cd exposure significantly reduced the number of aphids in the Cd-pretreated <italic>S. alfredii</italic> after 7 days of aphid infestation. The Cd concentration in the phloem exudates of <italic>S. alfredii</italic> was also high. Micro X-ray fluorescence mapping of aphids collected from Cd-treated plants revealed high levels of Cd in the stylets. In summary, Cd protects <italic>S. alfredii</italic> from <italic>A. fabae</italic> through toxicity, but not deterrence, which may be related to the abundance of Cd in the phloem.</p>