Manganese Accumulation and Tissue-level Distribution in the Australian Hyperaccumulator Gossia Bidwillii (Myrtaceae)

The manganese (Mn) hyperaccumulator Gossia bidwillii is a tree species native to subtropical eastern Australia where it occurs on Mn-rich soils. Here, we conducted the first Mn accumulation and tissue-level distribution study on wild and experimentally grown G. bidwillii. Gossia bidwillii plants were subjected to different levels of Mn (250 mu g g(-1), 500 mu g g(-1), 1000 mu g g(-1)) soil dosing treatments, whereas the wild G. bidwillii was sampled from growing on highly Mn-enriched natural soils. We used laboratory-based micro-X-ray Fluorescence (mu XRF) elemental mapping to elucidate in situ distribution patterns of Mn and other elements in hydrated wild and Mn-dosed G. bidwillii leaves. The data from wild G. bidwillii revealed that it can be strongly Mn-hyperaccumulating with foliar Mn concentrations of 39 000 mu g g(-1) and 24 000 mu g g(-1) in old and young leaves, respectively. In the Mn dosing trial, G. bidwillii accumulated 24 400 mu g g(-1) in old leaves and 17 100 mu g g(-1) in young leaves in the highest treatment level. The laboratory based mu XRF data revealed that Mn is uniformly enriched throughout the laminae and petioles of both young and old leaves in wild G. bidwillii; while in Mn-dosed G. bidwillii, the foliar Mn distribution was primarily concentrated at the leaf-tip and lamina. The approach employed by combining data from the field and controlled experiments was especially meaningful for investigating Mn accumulation in this species and gaining added insight into the phenomenon of Mn hyperaccumulation.

Automated summary

This study is the first to investigate manganese accumulation and tissue-level distribution in Gossia bidwillii. It was found that wild G. bidwillii has a strong ability to hyperaccumulate manganese, and experimental plants also accumulated significant amounts of manganese. Laboratory-based micro-X-ray fluorescence analysis revealed that manganese is uniformly distributed in the leaves and petioles of wild G. bidwillii, while in the manganese-dosed plants, manganese was primarily concentrated at the leaf tips and laminae.