Are plants ready for nanotech?

Oeiras, 03.11.10

Nanotechnology is a promising field with lots of questions. By, literally, manufacturing molecules, researchers work for applications in a wide range of fields, including agriculture. But any application in plants requires at least two answers: how toxic to plants are nanoparticles and, if in the plant, where do they go. ITQB researchers and collaborators tested the effect of quantum dots in cell cultures of Medicago, a model legume plant, and for the first time observed quantum dots inside a plant cell. The results are published in the Journal of Nanobiotechnology.

Quantum dots are very small crystals (5-30 nanometers) typically composed of cadmium, selenium and zync. Because they are toxic and insoluble, encapsulation in a soluble compound is required before application in living organisms. The custom made encapsulated quantum dots, specifically designed for this work, were added to Medicago sativa cell suspension cultures. Researchers found these quantum dots to be safe for biological applications within a specific concentration range (1-5 nM) above which cell viability and growth was increasingly reduced.

One of the attractive properties of quantum dots is their very precise light emitting properties. In practice, this means quantum dots come in different colours that can be defined by tailoring their size. And since they are extremely stable and bright, quantum dots can be traced inside organisms and cells. Using confocal microscopy, researchers observed the accumulation of quantum dots in the membrane, cytoplasm and nucleus of Medicago sativa cells. 

The ultimate goal of this work is to develop a nanostrategy to detect fungal infections in plants: by attaching molecules that specifically recognize fungal proteins or metabolites to quantum dots, the fungus presence in the cells can be detected even before symptoms develop. 
 
The multidisciplinary team involved in this work includes the cell biology expertise from FCUL and the labs of Biomolecular Diagnostics, Plant Cell Biotechnology, and Organic Synthesis from ITQB.

Original Article

Journal of Nanobiotechnology 2010, 8:24doi:10.1186/1477-3155-8-24

The impact of CdSe/ZnS Quantum Dots in cells of Medicago sativa in suspension culture

Ana R Santos, Ana S Miguel, Leonor Tomaz, Rui Malhó, Christopher Maycock, Maria C Vaz Patto, Pedro Fevereiro and Abel Oliva