N Nurmahanova A.S., Atabayeva S.D., Tleuberdy A., Alybayeva R.A., Asrandina S.S., Kenzhebayeva S.S. Action of cadmium ions on the structure of the root of some varieties of rice (Oryza sativa L.)

Әл-Фaрaби aтындaғы Қaзaқ ұлттық университеті, Алмaты қ., Қaзaқстaн *Е-mail: akmaral.nurmahanova@gmail.com

Abstract

Cadmium is one of the most mobile heavy metals. It is actively absorbed by plants, rather quickly
transported to their aerial parts. Rice has radial cadmium transport along the root tissues to xylem. The
movement of the metal along the xylem is fundamental in the roots. Results of researches of impact of
cadmium ions on various varieties of rice are given in this article (Oryza sativa L.). As an object of a research, 4 varieties of rice have been selected: Chapsari, Barakat, Bakanas, Madina. To reveal changes in
the structure of the root, within 7 days grew up several options of rice – control,100мкМFe + 200 мкМ
CdSO
4, 0мкМFe + 200 мкМ CdSO4, 200мкМFe + 200 мкМ CdSO4.The root of rice is outside covered
by rizodermy. The innermost layer of the cortex consists of cells of the endoderm. The thick wall of an
endoderma reliably protects the tissues and increases the power of root.At influence of concentration of
cadmium in100мкМFe + 200 мкМ CdSO
4the cell of exoderm became thickness for 9%in the variety of
Bakanas, andthe cells became thinner for 36%in sensitive varieties of Chapsari. During the researchthe
thickness of the root exoderm cells grown by a concentration of 0мкМFe + 200 мкМ CdSO4 of Bakanas
variety increased for 6%, and in the Chapsari variety the thickness decreased for 50%. Moreover, under
the action of 200мкМFe + 200 мкМ CdSO
4the cell of exodermwere thickened for 7%in the variety of
Bakanas, and they became thinner for 45% the variety of Chapsari. It seen that the thickness of exoderm
cells increased in the resistant variety of Bakanas by these options, and it is, contrary, decreasedin a
susceptible variety of Chapsari. Exoderm protects the root from the adverse effects of the environment
and prevents the accumulation of various toxic substances from the outside. The thickening of exoderm
shows the development of structural ability against a stress. Specialized complex structural indicators,
interconnection and interdependence determine sustainability. In the process of carrying out a research
under the influence of a stress, we have revealed communication of concrete structural indicators with
steady varieties of rice. As studies show, inhibition of root growth in the presence of cadmium is associated with its direct effect on cell division and stretching. The result of the negative effect of cadmium on
the physiological processes of plants is a decrease in their productivity. First of all, disturbances in the
normal life of plants are manifested in a decrease in the accumulation of biomass.
Key words: rice, cadmium, exoderm, endoderm, heavy metals.