Morphogenesis, pigment content, phytohormones and productivity of sweet pepper under the action of gibberellin and tebuconazole

Abstract

One of the main tasks of modern plant physiology is regulation of growth and development of cultivated plants in order to optimize the productive process. The attention of the scientific community is focused on the use of natural activators and growth inhibitors. We investigated the effect of foliar treatment with 0.005% solution of gibberellic acid (GA3) and 0.025% solution of the antigibberellic preparation tebuconazole (EW-250) on morphogenesis, leaf mesostructure, the content of photosynthetic pigments, the balance of endogenous phytohormones and productivity of Capsicum annuum L., Antey variety. The vegetation experiment was carried out in the conditions of soil-sand culture in vessels with a volume of 10 L. Treatment of plants was carried out in the budding phase. Morphometric parameters were determined every 10 days. The mesostructure of the middle tier leaves was studied in the fruit formation phase, and the chlorophyll content was determined in the raw material by spectrophotometric method. Analytical determination of endogenous phytohormones – indolyl-3-acetic (IAA), gibberellic (GA3) and abscisic (ABA) acids and cytokinins – zeatin (Z), zeatin-O-glucoside (ZG), zeatinribozide (ZR), isopentenyladenine (iP) and isopentenyladenosine (iPA) were performed by high performance liquid chromatography – mass spectrometry (HPLC-MS). With GA3 treatment, plant height increased considerably, while with EW-250, it decreased. Both regulators led to an increase in the number of leaves on the plant, the leaf raw biomass, stems and roots and the dry matter of the whole plant, the area of a single leaf blade and the total area of leaves on the plant. Under the action of EW-250, the chlorophyll content in the leaves surged, while under the action of GA3 it tended to decrease or did not change at all. Both regulators thickened the chlorenchyma and boosted the volume of the columnar parenchyma cells. GA3 treatment induced a rise in the thickness of the upper and lower epidermis, and EW-250 led, on the contrary, to a decrease. It is shown that after treatment with exogenous GA3, the content of endogenous IAA and ABA decreased and GA3 in plant stems increased. Instead, EW-250 caused a decrease in the levels of GA3, IAA and ABA in the stems. Exogenous GA3 enhanced the accumulation of endogenous GA3 and IAA and inhibited ABA in the leaves. Under the action of the retardant, the level of ABA in the leaves did not change, while GA3 and IAA decreased. Treatment of plants with the studied growth regulators caused a decrease in the pool of cytokinins (CK) in stems. EW-250 showed a significant rise in the hormone content in the leaves. After spraying with GA3 solution, the level of ZG, Z and ZR grew. Under the action of the retardant, the increase in the CK pool occurred exclusively due to the iP. Growth regulators optimized the productivity of sweet pepper plants: under the action of GA3 there was an increase in the number of fruits per plant, and after the use of EW-250 there was a rise in the average weight of one fruit. The obtained results showed that anatomical-morphological and structural-functional rearrangements of sweet pepper plants under the action of exogenous gibberellic acid and EW-250 took place against the background of changes in the balance and distribution of endogenous hormones. Increased photosynthetic activity, stimulation of growth processes of some plant organs and inhibition of others enlarged biological productivity of the culture.

Morphogenesis, pigment content, phytohormones and yield of tomatoes under the action of gibberellin and tebuconazole

“…It is found that there was a relatively low content of GA 3 in the control and experimental variants against the background of a sufficiently high level of ABA in tomato stems and leaves. The results obtained are similar to our previous ones (Rogach et al, 2020(Rogach et al, , 2021 and those of other authors (Ahmad et al, 2017), in particular when using similar regulators on tomato plants (Khalloufi et al, 2017) and flax (Kim et al, 2018).…”

“…Bobcat (ng/g of raw matter, n = 9 (3 (biological) × 3 (analytical)), x ± SE) mones under the influence of exogenous gibberellins were observed in the organs of tomato plants (Khalloufi et al, 2017) and zucchini (Song et al, 2019). It is found that the application of exogenous GA 3 and EW-250 led to significant changes in the growth rate of tomato plants, as indicated by our previous studies (Rogach et al, 2020(Rogach et al, , 2021. The increase in the linear shoot size of GA 3 -treated plants and the raw material masses of stem and leaf roots correlated with the increase in the content of endogenous growth stimulating hormones GA 3 and IAA in stems and leaves.…”

“…The application of this preparation in sweet pepper culture caused a decrease in the levels of GA 3 , IAA and ABA in the stems. Under the action of the retardant, the level of ABA in the leaves did not change, while GA 3 and IAA decreased it (Rogach et al, 2021).…”

“…It is shown that after treatment with exogenous GA 3 , the content of endogenous IAA and ABA decreased while GA 3 increased in the stems of sweet pepper plants. Native phytohormone enhanced the accumulation of endogenous GA 3 and IAA and inhibited ABA in sweet pepper leaves (Rogach et al, 2021).…”

“…Under the action of the growth stimulant, the chlorenchyma thickened, the cell volume of the columnar parenchyma increased, but the chlorophyll content in the leaves decreased. Such changes in the leaf apparatus under the action of GA 3 led to an increase in the quantitative indicators of the productivity elements of eggplant and peppers (Rogach et al, 2020(Rogach et al, , 2021.…”