The application of biostimulants Regoplant and Stimpo to increase wheat resistance to salinity conditions

aim. Investigation of bioprotective action of polycomponent biostimulants of natural origin Regoplant and Stimpo according to physiological and molecular genetic parameters of resistance of winter wheat plants (Triticum aestivum L.) varieties Antonivka ta Hoduval'nytsya odes'ka to the salinity conditions. Methods. The physiological parameters of resistance of experimental wheat plants obtained from seeds treated and untreated with solutions of Regoplant and Stimpo biostimulants used at concentrations of 50 μl/L and 75 μl/L grown under salt stress on 0,1 M sodium chloride solution were studied. Using Dot blotting method the degree of hybridization between cytoplasmic si/miRNA isolated from cells of experimental wheat plants grown under salinity conditions and mRNA of control plants grown in the absence of salinity conditions was determined. In the wheat embryo cell-free system of protein synthesis in vitro the silencing activity of si/miRNA on the template of mRNA isolated from cells of experimental wheat plants grown under salt stress conditions and control plants was studied. Results. It was found that the use of biostimulants Regoplant and Stimpo by soaking the seeds of wheat plants for 24 hours at concentrations of 50 μl/L and 75 μl/L improved the physiological parameters of wheat plants grown under salt stress conditions, which increased on average: seed germination – up to 69-75%, the length of seedlings – up to 28-37%, the length of roots – up to 41-42%, leaf area – up to 25-38%, the raw weight of seedlings – up to 48-53%, the dry weight of seedlings – up to 37-46 %, respectively, compared to control. The Dot-blot hybridization method showed that the largest decrease in the percentage of hybridized mRNA and si/miRNA molecules was observed in experimental wheat plants grown from seeds treated with Regoplant and Stimpo biostimulants under salt stress conditions - up to 66-75%, respectively, compared to control. The increase of silencing activity of si/miRNA on the template of mRNA isolated from experimental wheat plants obtained from seeds treated with Regoplant and Stimpo biostimulants and grown under salt stress conditions was shown to be 39-42%, respectively, compared to control. Conclusions. The use of biostimulants Regoplant and Stimpo in concentrations of 50 μl/L and 75 μl/L for presowing seed treatment contributes to the increase of the resistance of winter wheat plants to salinity conditions. Keywords: Triticum aestivum L., polycomponent biostimulants, resistance of wheat to salinity conditions, RNA interference.

Digestive characteristics and peptide release from wheat embryo proteins in vitro

The nutritional repair function of wheat embryo protein is determined by its digestive fate.

Wheat Germination Is Dependent on Plant Target of Rapamycin Signaling

Germination is a process of seed sprouting that facilitates embryo growth. The breakdown of reserved starch in the endosperm into simple sugars is essential for seed germination and subsequent seedling growth. At the early stage of germination, gibberellic acid (GA) activates transcription factor GAMYB to promote de novo synthesis of isoforms of α-amylase in the aleurone layer and scutellar epithelium of the embryo. Here, we demonstrate that wheat germination is regulated by plant target of rapamycin (TOR) signaling. TOR is a central component of the essential-nutrient–dependent pathway controlling cell growth in all eukaryotes. It is known that rapamycin, a highly specific allosteric inhibitor of TOR, is effective in yeast and animal cells but ineffective in most of higher plants likely owing to structural differences in ubiquitous rapamycin receptor FKBP12. The action of rapamycin on wheat growth has not been studied. Our data show that rapamycin inhibits germination of wheat seeds and of their isolated embryos in a dose-dependent manner. The involvement of Triticum aestivum TOR (TaTOR) in wheat germination was consistent with the suppression of wheat embryo growth by specific inhibitors of the TOR kinase: pp242 or torin1. Rapamycin or torin1 interfered with GA function in germination because of a potent inhibitory effect on α-amylase and GAMYB gene expression. The TOR inhibitors selectively targeted the GA-dependent gene expression, whereas expression of the abscisic acid-dependent ABI5 gene was not affected by either rapamycin or torin1. To determine whether the TaTOR kinase activation takes place during wheat germination, we examined phosphorylation of a ribosomal protein, T. aestivum S6 kinase 1 (TaS6K1; a substrate of TOR). The phosphorylation of serine 467 (S467) in a hydrophobic motif on TaS6K1 was induced in a process of germination triggered by GA. Moreover, the germination-induced phosphorylation of TaS6K1 on S467 was dependent on TaTOR and was inhibited by rapamycin or torin1. Besides, a gibberellin biosynthesis inhibitor (paclobutrazol; PBZ) blocked not only α-amylase gene expression but also TaS6K1 phosphorylation in wheat embryos. Thus, a hormonal action of GA turns on the synthesis of α-amylase in wheat germination via activation of the TaTOR–S6K1 signaling pathway.

Optimization of Wheat Embryo Globulin Fermenting Process and Variation in Properties during Fermentation

In this study, an efficient preparation technology of fermented wheat embryo globulin (FWEG) was developed, and the changes of nutritional characteristics and structure of FWEG were studied during the fermentation process. Protein concentration was selected as the evaluation index, and Box-Behnken experiment design was employed for optimizing the preparation conditions of FWEG. The nutritional characteristics of FWEG during fermentation were dissected through SDSPAGE and free amino acid assay. The structural changes of FWEG during fermentation were analyzed through circular dichroism, sulfhydryl detection, and electron microscope scanning. The optimum fermentation conditions were determined. The protein concentration of FWEG reached 2.09 ± 0.15 mg mL-1 under the optimal conditions. Acidity, contents of protein and protease increased while the content of FWEG decreased in the fermentation. The concentration of small molecule protein and free amino acids went up along with the fermentation. Due to changes in the secondary structure of FWEG and massive released of sulfhydryl groups, the surface of FWEG became uneven during the fermentation. The optimal fermentation process was noticed after Baker's yeast fermentation, lasting for 3.2 h; Lactobacillus plantarum was inoculated, and the fermentation continuous for 14.8 h, in which the ratio of baker's yeast to L. plantarum (V:V) was 1:2. The nutritional quality of wheat embryo globulin was improved, and its structure was changed during fermentation, which increased the absorption of FWEG and enhanced its suitability as a food ingredient. © 2019 Friends Science Publishers