Two Bamboo Species (Phyllostachys auresulcata ‘Spectabilis’ and Pleioblastus chino ‘Hisauchii’) Exhibit Different Responses to Excess Copper

Copper (Cu) is an essential micronutrient for plant metabolism, but when present in excessive amounts, could lead to inhibition of plant growth by deteriorating plant physiological metabolisms. Bioenergy crops can be used for producing either biodiesel or bioethanol, which is a sustainable option for possibly removing metal pollutants by phytoremediation.

Bamboos occur naturally in tropical, subtropical and temperate regions of all the continents in the world (except Europe), from sea level to 4000 m. Some perennials bamboo species are known to have several merits, including high stress tolerance to various factors, high growth and biomass production.

In order to develop dual potentials of bamboo species for bioenergy feedstock and phytoremediation activity in Cu-polluted areas, Dr. JIANG Li et al. examined plant growth, physiological properties, Cu absorb, accumulation and translocation abilities of two bamboo species (Phyllostachys auresulcata ‘Spectabilis’ and Pleioblastus chino ‘Hisauchii’ in a range of Cu supplies up to excessive rates using pot-soil-culture. Pots were irrigated with aqueous solutions of Cu in concentrations of 500, 1000 and 2000 mg CuSO₄·5H₂Okg⁻¹, against the control (tap water). Plant growth, chlorophyll contents, photosynthesis rate, malondialdehyde (MDA) content, Cu concentrations in leave, stem and root, and Cu contents in shoot per pot were measured after transplanted plants were grown under excess Cu treatments for 60 days.

The results showed that two bamboo species had different responses to tolerance and allocation of supplied Cu. As Cu treatments rose, the percentage of senescent shoot and MDA content increased, and the chlorophyll content and photosynthetic capacity decreased. Such changes in Hisauchii were more obvious than in Spectabilis. However, number of emerged shoots did not differ between the two species across four Cu treatments. In the efficiency of decontamination, Hisauchii was more effective than Spectabilis, since either the Cu concentrations in leaves, stems and roots or Cu contents in shoot per pot in Cu treatments from 500 to 2000 mg kg⁻¹ were higher in Hisauchii than in Spectabilis.

This study revealed that the potential capability of absorbing Cu might cause the different response to Cu stress between the two bamboo species. Both bamboo species can be considered to exhibit enough potential to develop in Cu-polluted areas of China as bioenergy resources and phytoremediation plants. The result was published in BioEnergy Research in December 2013.