EFFECT OF CHITOSAN FORMULATIONS OF DIFFERENT BIOLOGICAL ORIGIN ON TOBACCO (NICOTIANA TABACUM L.) PR-GENES EXPRESSION

Abstract

During the life cycle, plants sustain a significant impact of external abiotic and biotic stress factors. Their reactions to the factors are complex and multi-level; they include changes in the transcriptomic, cellular, and physiological levels. The effect of chitosan formulations of different biological origin and molecular weight on the relative expression pattern of five pathogenesis-related (PR-)genes of tobacco (PR1a, PR2a, PR2b, PR3a and PR3b) was studied. Based on the analysis of nucleotide sequences deposited in the GenBank, specific primers for the amplification of exon regions of the five PR-genes were designed and the optimal conditions for real-time PCR, using SYBR Green dye determined. The relative expression pattern of the genes under study was influenced by the molecular weight of the chitosan used, the time passed after treatment and the very gene; The expression was generally higher when low-molecular chitosan fractions were used. Regardless of the biological origin of the elicitor, the formulations had the smallest effect on the expression of gene PR1a and the highest effect on the expression of the main chitinase gene (PR3b). Nicotiana tabacum L. leaves possess sensory systems triggering response reactions on the transcriptional level. The nature of the interaction between chitosan and cell sensor may differ, however, depending on the biological origin of chitosan, its molecular weight and the degree of deacetylation. The obtained results prove high sensitivity of defensive plant systems to the tested chitosan formulations and the ability of these formulations to penetrate tissues and interact with the relevant cellular sensors.