Copper localization in Cannabis sativa grown in a

Copper localization in Cannabis sativa grown in a copper-rich solution Piera Bonatti, Laura Arru, Sara Rognoni, Micaela Baroncini, Pierdomenico Perata University of Modena & Reggio Emilia

PHYTOREMEDIATION The use of plants to remove heavy metals and other pollutants from soils and waters

PHYTOEXTRACTION OF HEAVY METALS The most common heavy metals are: Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sn, Zn Are often very toxic to living organisms over a certain concentration threshold

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? HYPERACCUMULATOR SPECIES Represent <0, 2% of all angiosperms ~400 species are hyperaccumulators HYPERACCUMULATION THRESHOLDS: Zn, Mn: 10 000 m. G/KG Co, Cu, Ni, Se: 1 000 m. G/KG Cd: 100 m. G/KG These thresholds are 2 -3 orders of magnitude higher than in normal plant species

Alyssum serpyllifolium Brassica juncea HYPERACCUMULATOR SPECIES & PHYTOREMEDIATION PLANTS Thlaspi caerulescens Liriodendron tulipifera Pteris vittata

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? Hyperaccumulator species must be hypertolerant to heavy metals Pteris vittata accumulates up to 22 000 m. G/KG of arsenic, with no phytotoxicity simptoms up to 10 000 m. G/KG As (Ma et al, Nature, 2001; Wang et al. , Plant Physiol. , 2002)

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? Hyperaccumulator species = low biomass? Thlaspi caerulescens, a Zn/Cd hyperaccumulator, produces little biomass (2 -5 t/ha) (Mc. Grath et al. Adv. Agronom. 2002) Alyssum bertolonii and Berkheya coddii, Ni hyperaccumulators, produce up to 9 -22 t/ha biomass (Robinson, 1997)

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? Can high biomass compensate for lower accumulation? Thlaspi caerulescens can extract 2000 g Cd / ha / year Cannabis sativa Can extract 126 g Cd / ha / year

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? Hemp as a high biomass plant for phytoextraction? Phytoxicity? Use of fibers after phytoextraction? Zn toxicity on hemp plants

WHICH PLANT SPECIES FOR PHYTOEXTRACTION? Hemp as a high biomass plant for phytoextraction? Not hyperaccumulator High biomass Could be used for phytoremediation if fibers can be commercialized

COPPER SOIL CONTAMINATION Copper is required for the physiology of the plant An EXCESS of copper in the soil results in phytotoxic effects Copper is an essential cofactor for many enzymatic activities in animals too An EXCESS of copper is excreted by animals (liver, bile) Genetic diseases result in altered Cu homeostasis (Wilson disease) Exposure to the metal copper may increase the risk of Alzheimer's disease

COPPER SOIL CONTAMINATION Copper sulfate is used in agricuture, including organic farming Possible copper build-up in the soil which at high levels can be harmful to earth worm populations. In response to such environmental concerns copper should be phased out of usage as soon as possible

The aim of this work is the localization of Cu in hemp plants grown in a copper-enriched solution Cu. SO 4

Energy Dispersive X-ray Spectra (X-EDS) STEM Cu LEAF EPIDERMIS Cu

HYSTOLOGICAL LOCALIZATION OF Cu LEAF EPIDERMIS 40 m

HYSTOLOGICAL LOCALIZATION OF Cu TRICOMES 80 m

CITOLOGICAL LOCALIZATION OF Cu CELL WALL VACUOLE PLASTID

CONCLUSIONS Hemp grown in hydoponics accumulates cooper in the leaves (tricomes) Copper was not detected in fibers Further work is needed to evaluate the fibers quality from hemp grown in open field in the presence of copper sulfate