Analysis of Soluble Carbohydrates, Proteins and Lipids in Shoots of M 7 Apple Rootstock Cultured in vitro during Regeneration of Adventitious Roots

Metabolic changes accompanying adventitious root regeneration of M 7 apple rootstock (Malus pumila) were studied. Conditions that stimulate different root regenerative capacities were formulated in culture in vitro. The graduation of rooting was the result of exogenously supplied auxin and level of macronutrients in the medium. For the elaborated experimental model system the quantitative and qualitative analyses of carbohydrates, proteins and lipids have been performed for consecutive stages of root development such as initial phase, stage of intensive cell division in the induction zone, formation of root primordia and the connection of vascular systems berween the shoot and root. The level of carbohydrates was determined with colorimetric methods and GC-MS spectrometry. In the course of the rooting process in shoots the occurrence of glucose, fructose, sorbitol, inositol and a trace amount of galactose and ribose was observed, but not sacharose. The content of soluble saccharides in the first 10 days of rooting gradually increased and was related to the stage of intensive cell division at the bases of shoots. Particularly, the amount of fructose in the shoots was correlated with rooting ability. In the period of primordia differentiation and root elongation the content of soluble saccharides dropped to the level observed at the beginning in shoots having been taken for examinations. During rhizogenesis in shoots treated with auxin, the chlorophyll content decreased. The soluble proteins in that process varied, being slightly higher at the moment of primordia formation in conditions most favourable for rooting. No specific polypeptides synthesized de novo were found in that fraction of proteins. Slightly increased lipids accompanied the period of root primordia formation.