Effect of gibberellin on the use of reserve substances deposited in Vicia faba L. seeds at the phase of heterotrophic development under the conditions of photo- and skotomorphogenesis

Abstract

Under conditions of a combination of an external (light/dark) factor and a hormonal factor (gibberellic acid) during germination, changes in the functioning of the source-sink system in heterotrophic phase of horse beans development were studied. The increase in the epicotyl, root and seedling length, both in light and dark, as well as in the dry matter of the mass of the seedling organs, was found under drug action. Reserve substances were used more intensively under gibberellin and skotomorphogenesis influence. It is evidenced by the minimum dry matter of cotyledons and higher reserve utilization rates for root and epicotyl formation. Gibberellin stimulated starch breakdown in both, but during germination in dark, the rate of starch use was higher. Other content of sugars in skotomorphic seeds was associated with more intensive outflow for organogenesis needs: formation of root and epicotyl structures. The changes in the content of starch were higher than the changes in nitrogen content in skotomorphic and photomorphic seedlings. This indicates that gibberellin stimulates hydrolysis of reserve protein only after starch hydrolysis in dark. No specific gibberellin regulation of phosphorus and potassium outflow from seeds for organogenesis needs was found, suggesting sufficient mineral nutrients supply to ensure their re-utilization during germination, photo- and skotomorphogenesis processes.

Utilization of spare substances of Zea mays L. seeds during germination under the combined effect of growth regulators and presence or absence of light

“…Previously, a lower content of protein nitrogen under conditions of skotomorphogenesis in control seedlings of horse beans than in photomorphic ones was found. The content of protein nitrogen decreased and the content of non-protein form significantly increased under gibberellin action (Kuryata et al, 2020).…”

“…Furthermore, the issues of the source-sink system functioning during heterotrophic phase of plant development as the period of seed germination and formation of other organs remain practically unspecified. The peculiarities of the usage of deposited spare substances of various chemical structures and nutrients for the needs of organogenesis are also little known (Poprotska et al, 2019; Kuryata et al, 2020).…”

“…Changes in the intensity of growth of different organs of seedling under conditions of photo-and skotomorphogenesis are obviously accompanied by differences in the intensity of use of deposited spare substances, resulting in changes in the degree of tension between source and sink activity. In some works, data represent the possibility of regulating the rate of utilization of spare compounds for growth and development by external and internal factors (Kutscherа, Briggs, 2003; Kuryata, Polyvanyi, 2018; Kuryata et al, 2020). Therefore, the aim of our study was to establish the effect of gibberellin and its antagonist tebuconazole on the functioning of the "depot of assimilates -growth" system during the germination of maize seeds under photo-and skotomorphogenesis conditions.…”

Peculiarities of mesostructure and pigment complex formation in leaves of scoto- and photomorphic seedlings of horse beans under the gibberellin and tebuconazole impact

“…Cytogenesis and histogenesis occur due to reserve compounds that are localized in the cotyledons. In our previous work, gibberellic acid stimulated the use of reserve carbohydrates and nitrogen-containing compounds for ontogenetic needs of seedlings, and the use of gibberellin biosynthesis inhibitor tebuconazole, in contrast, retarded the use of seed reserves [31,32]. However, in the literature there are only single data on seedlings lipid metabolism under conditions of scoto-and photomorphogenesis under the action of gibberellins [33].…”

Anatomic-physiological changes in horse bean seedlings under the influence of gibberellin and tebuconazole at conditions of photo- and scotomorphogenesis

“…Changes in the growth rate of different seedling organs under conditions of photo-and scotomorphogenesis are obviously accompanied by differences in the rate of use of reserve substances deposited in the cotyledons, resulting in changes in the degree of tension between source and sink activity. In some works, data are presented that indicate the possibility of regulating the rate of reserve compounds utilization for the needs of growth and development by external and internal factors [7,15,16].…”