Problems of investigation of chemical elements accumulation and hyperaccumulation by plants
aInstitute of Soil Science and Agrochemistry SB RAS
Ac. Lavrentyev ave., 8/2, Novosibirsk, 630090 Russia
bFederal Research Center on Coal and Coal Chemistry SB RAS (Institute of Human Ecology)
Leningradskii prosp., 10, Kemerovo, 650065 Russia
*e-mail: syjil@mail.ru
The article is a review of the world published works on the problems of chemical elements (CE) accumulation by higher plants. Research issue urgency is determined by necessity of theoretical studying of element chemical cycle and by application-oriented aspects such as resource plants quality and safety, bioindicators and phytoremediators searching, estimating of anthropogenic pollution level and the like. A wide range of terminological and classification collisions under different investigating approaches demands some urgent solutions. In the paper there are carefully considered terminology, classification and criteria for different plant groups to be distinguished due to different strategies of chemical elements accumulation. In contrast to normal plants, resistance to CE high concentrations can be defined by different physiological mechanisms that lead to forming the main groups of excluders, bioindicators, and hyperaccumulators. A special consideration is given to hyperaccumulator plants of certain CE and to reasons for attributing taxa to the given group. They are threshold values of different chemical elements content, concentration and translocation factors and others. Considered also is the problem of plant surface contamination depending on biological features and of its impact on the results of CE content assessment. Some examples of wrong data interpretation of CE accumulated by plants are given. On the base of the investigation results it is established that in order to get the most accurate estimate of plant accumulation potential, especially with the aim to specify hyperaccumulator plants, one should take into account the following factors: viability of investigated population, rated threshold values exceeding CE content for certain elements, high values of accumulation and translocation factors, and foliar contamination degree. Diverse and multi-aspect approach to a plant accumulation potential enables avoiding a great deal of current collisions.
