The ecophysiology, genetics, adaptive significance, and biotechnology of nickel hyperaccumulation in plants

Assessment of plant diversity and foliar chemistry on the Sri Lankan ultramafics reveals inconsistencies in the metal hyperaccumulator trait

“…Hyperaccumulation in plants is recognized as the exceedance of metal(loid)‐specific shoot concentrations, at least an order of magnitude higher compared to other plants growing on the same soil (Brooks, 1998). Several reviews have synthesized the current state of knowledge of metal(loid) hyperaccumulators from around the world and provided perspectives from foundational empirical studies (Ferrero et al, 2020; Galey et al, 2017; Rajakaruna et al, 2009; Teptina et al, 2018).…”

“…The genetics of plant metal hyperaccumulation is such that it can vary between obligate, that is, species that constituently hyperaccumulate metals or metalloids when found on metalliferous soils, and facultative species that hyperaccumulate at some but not at all sites (Pollard et al, 2002). Established hypotheses about the adaptive significance of the trait (Boyd, 2004, 2012; Ferrero et al, 2020) focus on the Northern Hemisphere species, especially a number of species in Brassicaceae, such as Noccaea caerulescens , Odontarrhena muralis , and Streptanthus polygaloides (Macnair, 2003; Meindl & Ashman, 2015; Pope et al, 2013). Studies on Southern Hemisphere hyperaccumulators native to South America, the Western Pacific, primarily New Caledonia, Australia and Southeast Asia have revealed that many ultramafic outcrops are major centers for plant diversity and endemism, often rich in metal hyperaccumulator plant species (Galey et al, 2017; Jaffré et al, 2013; Proctor, 2003).…”