Evaluation of Effect of Exogenous Molybdenum and Tungsten on Seed Germinability and on Symptoms of Virus Infection in Plants

Abstract

Crop production is the basis of agriculture in Kazakhstan. Soils in Kazakhstan suffer from molybdenum deficiency. Molybdenum deficiency in plants is characterized by the stunted growth, poor seed setting, fruit deformation and reduced plant resistance to diseases. Molybdenum catalyzes key steps in the metabolism of nitrogen, carbon and sulfur. It promotes the biosynthesis of the phytohormones of abscisic acid and indole-3-butyric acid. An increase in molybdenum concentration leads to an increase in aldehyde oxidase activity. Aldehyde oxidase generates hydrogen peroxide during viral infection; hydrogen peroxide triggers a hypersensitive response, strengthens cell walls and prevents the spread of viral infection. Molybdenum is biologically inactive until a special complex called molybdenum cofactor is formed. For the formation of the latter it is necessary for molybdenum to be in the state of molybdate anion. There are five known plant molybdoenzymes: aldehyde oxidase, sulfite oxidase, nitrate reductase, xanthine dehydrogenase and mitochondrial amidoxime resuctase. The aim of this work is to find the optimal concentration of molybdenum for aldehyde oxidase activation. The objectives of the conducted experiment are: -to apply an efficient and cost-effective method to replenish molybdenum deficiency in the experimental plant; -to demonstrate the effect of molybdenum on the development of virus infection of the infected plant. As a result, it was proved that with the increase of concentration from 0.1 mM to 1 mM, the activity of aldehyde oxidase increases, which contributes to the increase of seed germination. The optimal concentration for seed germination is 1 Mm molybdenum concentration. As the concentration of molybdenum increases, the resistance of adult plants to virus infection also increases. Thus, 1 mМ molybdenum concentration is optimal for seed germination and resistance to virus infection.