Physiological And biochemical mechanisms

of herbs adaptation in conditions of Lake Baikal

M.A. Zhivetyev, I.A. Graskova, V.K. Voinikov

Siberian Institute of Plant Physiology and Biochemistry SD RAS, Irkutsk, 664033, Russia

The research of state of ecological systems both Lake Baikal and area, testing climate-generate influence of this lake, was actually. The plant adaptation to unfavorable factors of environment, including a low temperature, touch on protein, lipids, carbohydrate metabolism. Some signal molecule is necessary to switching on adaptive process. One of them are oxygen active forms. So long as active forms of oxygen play the important role in beginnings of adaptation, the peroxidase is attract attention of researcher. Peroxidase is enzyme, which participate in metabolism of hydrogen peroxide end execute the major function in oxidation stress.

We was research leafs of plants of three species, growing in Irkutsk and on the southeastern shore of Lake Baikal. These species are Achillea asiatica Serg., Taraxacum officinale Wigg., Plantago major L. These species are medicinal herbs. In leafs of it we was identify the activity of peroxidase, the content of fatty acids, sugars, stress-induced proteins.

The variation of activity of weak-associated with plant cell wall and soluble peroxidases of three species of medicinal herbs has been identified for the first time subject to thermal regime and subject to place of growth.

In October the coming of negative temperature led to slump of peroxidase activity of plants, growing in Irkutsk. Inversely, plants, sprouting on shores of Lake Baikal, were intensifying activity of this ferment.

All described above can be evidence of initiation of unlike adaptation mechanisms in Irkutsk end at Baikal shores subject to environmental conditions.

Termostability and optimal pH of weak-associated with plant cell wall and soluble peroxidases was shown to change in relation to natural conditions and season of year. Also the activity of peroxidase was variable during vegetation period.

Pic. 1. The variation of activity of weak-associated with plant cell wall and soluble peroxidases of medicinal herbs: 1 – activity of weak-associated with plant cell wall peroxidase; 2 – activity of soluble peroxidase; 3 –activity of total peroxidase; 4 – minimum of air tempetature in day of sampling; 5 – soil tempetature in five centimeter depth; 6 – average daily air tempetature; 7 – maximum of air tempetature in day of sampling; 8 – minimum of air tempetature in day before sampling; А – Taraxacum officinale, settlement Vydrino, shore of Lake Baikal, 2009; В – Taraxacum officinale, town Irkutsk, 2009; С – Achillea asiatica, settlement Vydrino, shore of Lake Baikal, 2009; D - Achillea asiatica, town Irkutsk, 2009; E – Plantago major, settlement Vydrino, shore of Lake Baikal, 2009; F – Plantago major, town Irkutsk, 2009.

Dehydrine expression was followed by spike of peroxidase activity (and, a priori, an increase of hydrogen peroxide concentration).

Increase of content of sugar, doing cryoprotector function, was shown to end of vegetation period. The accumulation of sugars on shores of Lake Baikal was going on greater than it in Irkutsk.

Pic. 2. Content of sugar of medicinal herbs: А – settlement Vydrino, shore of Lake Baikal; В – town Irkutsk.

In autumn, the accumulation of sugars, stressful proteins (stress-induced proteins) end unsaturated fatty acids in leafs of plants have been registered in Lake Baikal larger then in Irkutsk. This complex of adaptation mechanisms can be used in the capacity of marker of state of plants in natural conditions of habitation.