Filipino scientists discover new plant species with great phytoremediation potential

A new hypernickelophore species of Phyllanthus (Phyllanthaceae) was discovered by the team of Marilyn Quimado, Edwino Fernando, Lorele Trinidad and Augustine Doronila during their botanical exploration of ultramafic sites in Luzon and Mindanao.

Phyllanthus erythrotrichus was located in Sta. Cruz, Zambales while Phyllanthus securinegoides, previously only analyzed through herbarium specimens, was found thriving in Taganito, Surigao del Norte. Both were compared to a known hypernickelophore, Phyllanthus balgooyi, collected by the group earlier in the cities of Narra and Puerto Princesa in Palawan.

Phyllanthus erythrotrichus and P. securinegoides have more than 10,000 µg g-1 nickel in the leaves and 1,195 µg g-1 and 4,636 µg g-1 in the roots, respectively. Phyllanthus balgooyi accumulated 7,638 µg g-1 of nickel in the leaves while its roots had higher nickel content of up to 8,086 µg g-1. Phyllanthus erythrotrichus and P. securinegoides have translocation factor (TF) and bioaccumulation bactor (BAC) values of more than 1.0. This suggests that the species have great potential in phytoremediation, specifically, in the phytoextraction of nickel.

Phytoremediation utilizes green plants and their related microorganisms to decrease or relieve contamination in soils, sludges, sediments, surface water or ground water. One of its subprocesses, phytoextraction, uses plants to remove toxic components like heavy metals from soil or water.

The three species of Phyllanthus are prominent in ultramafic scrub communities and hence, should be used in ecological restoration of mined-out nickel lateritic areas. The implications of the unique adaptation of these species are also discussed in relation to a conservation strategy for their natural populations.

Results of the study have been recently accepted for publication in the special volume on Serpentine Ecology in the coming edition of Australian Journal of Botany.