Scientific Journal of KubSAU

In the Southern Federal University on the genetic basis of sunflower inbred line 3629, a collection of plastid mutants with varying degrees of chlorophyll deficiency was created by inducing Nnitrosomethylurea. Chlorophyll content was associated with their photosynthetic activity. It was found that the lower the chlorophylls content in mutant plastids, the lower the sugar concentration in plant tissues. For example, during the entire period of plant growth for whites (1.0-3.0 % chlorophylls a+b from control) var- 10, var-17 and yellows (6.0-9.5 % chlorophylls a+b from control) var-29, var-33 leaf areas of variegated mutants depending on the development phase and the content of green pigments are characterized by a low (2-7 fold) sugar content. Yellow-green (75.5% chlorophylls a + b from control) leaves of en:chlorina- 7 contain a higher level of carbohydrates, although it is 1.5-2 fold lower than at line 3629. Monosaccharides are products of hydrolytic reactions catalyzed by β- glycosidases. It was shown, that the activity level of β- galactosidase and β-glucosidase exceeded the corresponding indicators of the control at 1.5-2 and 2-7 fold, respectively. Similarly to enzymes from the water-soluble fraction, membrane-bound β- glycosidases also showed increased activity in the leaves of the investigated mutants, compared to the control green plants of 3629. Consequently, the activity of β-glycosidases increases dramatically in leaf tissues with deficiency of photosynthetic. Thus, chlorophyll mutations can lead to a change in the expression of nuclear genes, resulting in a significant increase in the activity of β-glycosidases in the mutant organelles themselves