Cadmium hyperaccumulation as an inexpensive metal armor against disease in Crofton weed. (December 2020)

• Record Type: Journal Article
• Authors: Dai, Zhi-Cong; Cai, Hong-Hong; Qi, Shan-Shan; Li, Jian; Zhai, De-Li; Wan, Justin Siu Hung; Du, Dao-Lin
• Is Part Of: Environmental pollution. Volume 267(2020)
• Publication Date: 2020-12
• Subjects: Heavy metal -- Enemy release -- Plant pathogen -- Plant defense -- Elemental defense hypothesis; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115649
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Invasive plants readily invade metal-contaminated areas. The hyperaccumulation of toxic heavy metals is not an uncommon feature among plant species. Although several hypotheses were proposed to explain this phenomenon, it is currently unclear how hyperaccumulation may benefit plants. The invasive Crofton weed ( Ageratina adenophora ) is a known hyperaccumulator of chromium and lead. We previously found that the species can also hyperaccumulate cadmium. The role of phytoaccumulation in defense to pathogen attack is unclear. We inoculated A. adenophora plants with a common generalist pathogen ( Rhizoctonia solani ) to test its resistance under cadmium treatment. We found evidence that cadmium hyperaccumulation reduced pathogen infection in A. adenophora . Our findings indicate elemental defense is highly cost efficient for hyperaccumulators inhabiting metal-contaminated sites, where plants were only modestly affected by cadmium. The reduction in pathogen damage conferred by cadmium was relatively high, particularly under lower cadmium levels. However, the benefits at higher levels may be capped. Elemental defense may be a key mechanism for plant invasion into polluted sites, especially in regions with widespread industrial activity. Our study highlights the importance of testing different metal concentrations when testing plant resistance and the importance of considering enemy attack when selecting plants for phytoremediation. Graphical abstract: Image 1 Highlights: Elemental defense may be a key to invading metal polluted sites for alien plants. Fungal infection is reduced under cadmium accumulation in invasive Crofton weed. Defense is inexpensive, but appears to be capped under higher levels of cadmium. The importance of testing elemental defense at lower metal levels is highlighted.