ABSTRACT
Fig. 4.17 The fluorescence spectra of secretory cells of developing cone from Larix decidua. Unbroken line - secreting cell; broken line - released resin on the cone surface
4.2.1.4 Salt-containing cells Salt-containing glands of Chenopodium album include crystals, which fluorescence in yellow, being excited by light with maximum 420 nm, or in blue at the UV (360-380 nm) excitation (see Chapter 2, Section 2.2.2.4). Seeds of the plant also contain green-yellow fluorescing crystals, but there are no any glandular structures on the surface. 1, 3, 5, and 8-d-old seedlings of the plant were developed from seeds moistened with water or the salt solutions, and their fluorescence was analyzed. Each seedling has greenyellow fluorescence at a tip (developing root meristem) and red fluorescence - in part near the seed (developing leaf meristem in primary leaf forming from cotyledon). Only after 8 d of the seed germination in the red fluorescing part of the seedlings, which later transform into a primary
leaf, and glands with salt crystals are seen. There are no such crystals in green-yellow fluorescing tip of the seedling, from which the primary root will arise. The nature of the salts, which form the salt gland, has been studied in the experiments with the seed germination in various salt media - from water to 10“4-10_1M salt solutions of sodium sulphate, sodium carbonate, potassium chloride and sodium chloride. As shown in Table 4.4, in the red-fluorescing part of the seedling the green-fluorescing spots arose in seedlings developed in sodium sulphate salts. Other salts used were not effective. Only 10_1M sodium sulphate stimulated the salt gland formation. The green-yellow fluorescence of salt crystals in the glands was seen in the red-fluorescing part of the seedling earlier, when similar glandular structures arise in a control (after 8 d of the seed germination). The highest concentration of sodium sulphate 10"1 M is effective for the salt gland arising. After 8 d of the development, the fluorescence intensity in salt glands formed on the lower side of the primary leaf strongly enhanced and was about 210% of control, while red fluorescence decreased up to 4547% of control due to the formation of the glandular structures. Thus, fluorescence of salt crystals in forming salt glands may be a marker for the study of plant seed development among halophytes.
