Microtubule cytoskeleton participates in realization of autophagy, which is crucial for cell surviving under the influence of stressful stimuli in Arabidopsis thaliana

Abstract

Aim. Significant role of microtubules (MTs) in the regulation of autophagy development is widely described. In yeasts and animal cells, MTs provide processes of maturation and traffic of autophagosomes. In plants, autophagic mechanisms still poorly understood despite its fundamental role for cellular functioning. We investigated an involvement of microtubule cytoskeleton in the realization of autophagy, a process, which is essential for cell surviving under stress conditions. Methods. Arabidopsis thaliana seedlings were subjected to metabolic- and salt stresses, as well as ultraviolet B irradiation as well as to synergistic action of stressful stimuli and E-64 inhibitor of autophagy-related cysteine proteases. The interrelation between MTs and stress-induced autophagy was investigated via performing of expression profiling of α-tubulin and atg8 isotypes. Results. It was shown that synergistic action of stressful factors and autophagy inhibition was realized in decreased cell viability that confirms the role of autophagy in the mediation of abiotic stress influences. Obtained results suggest stress-specific involvement of certain isotypes of atg8 and α-tubulin in autophagy development at the transcriptional level. Conclusions. Our work underlines the role of microtubule cytoskeleton in realization of autophagy, as an adaptive process, under adverse abiotic influences.

Keywords: autophagy, stressful stimuli, Arabidopsis thaliana, α-tubulin, atg8, programmed cell death.