Radio-Protective Effects of Stigmasterol on Wheat (Triticum aestivum L.) Plants

Effect of stigmasterol and polyglycerol polyricinoleate concentrations on the preparation and properties of rapeseed oil-based gel emulsions

Emulsion gels mimic the rheological properties of solid and semi-solid fats, offering a viable solution to replace conventional fats in low-fat food formulations. In this study, gel emulsions stabilized with stigmasterol (ST) and polyglycerol polyricinoleate (PGPR) complexes were prepared. Initially, we examined the effect of the ST/PGPR complex on the mechanism of gel emulsion stabilization. Our findings revealed that the gel emulsion formulated with 3% PGPR and ST exhibited a robust structure, effectively stabilizing the entire system and ensuring uniform distribution, and increasing ST concentration led to greater stability of the gel emulsion system. Stability assessments demonstrated that gel emulsions containing 3% PGPR and varying ST concentrations exhibited remarkable thermal stability and effectively delayed oil oxidation. These results underscore the high stability of gel emulsions stabilized with the ST/PGPR complex, highlighting their potential as a margarine substitute.

Overexpression of the OsFes1A increased the phytosterols content and enhanced drought and salt stress tolerance in Arabidopsis

MAIN CONCLUSION

Overexpression of the rice gene, OsFes1A, increased phytosterol content and drought and salt stress tolerance in Arabidopsis. Phytosterols are key components of the phospholipid bilayer membrane and regulate various processes of plant growth and response to biotic and abiotic stresses. In this study, it was demonstrated that the overexpression of OsFes1A (Hsp70 nucleotide exchange factor Fes1) increased phytosterols content and enhanced tolerance to salt and drought stress in Arabidopsis. In transgenic plants, the average content of campesterol was 17.6% higher than that of WT, and the average content of β-sitosterol reached 923.75 μg/g, with an increase of 1.33-fold. In fes1a seeds, the contents of campesterol and β-sitosterol reduced by 20% and 10.93%, respectively. In OsFes1A transgenic seeds, the contents of campesterol and β-sitosterol increased by 1.38-fold and 1.25-fold respectively. Furthermore, the germination rate of transgenic Arabidopsis was significantly higher than WT under stress (salt, ABA, and drought treatment). Under salt stress, transgenic plants accumulated a lower MDA content, higher chlorophyll content, and POD activity relative to the wild type, while the mutants showed the opposite pattern Our study found multiple other functions of OsFes1A beyond the defined role of Fes1 in regulating Hsp70, contributing to the better understanding of the essential roles of Fes1 in plants. Meanwhile, it provides the theoretical basis for developing high phytosterol crop varieties.

Tomato Sterol 22-desaturase Gene CYP710A11: Its Roles in Meloidogyne incognita Infection and Plant Stigmasterol Alteration

Sterols are isoprenoid-derived lipids that play essential structural and functional roles in eukaryotic cells. Plants produce a complex mixture of sterols, and changes in plant sterol profiles have been linked to plant-pathogen interactions. β-Sitosterol and stigmasterol, in particular, have been associated with plant defense. As nematodes have lost the ability to synthesize sterols de novo, they require sterols from the host. Tomato (Solanum lycopersicum) plants infected by the plant parasitic nematode Meloidogyne incognita show a reduced level of stigmasterol and a repression of the gene CYP710A11, encoding the sterol C-22 desaturase that is responsible for the conversion of β-sitosterol to stigmasterol. In this study, we investigated the role of the tomato sterol C-22 desaturase gene CYP710A11 in the response to infection by M. incognita. We explored the plant-nematode interaction over time by analyzing the plant sterol composition and CYP710A11 gene regulation in S. lycopersicum after M. incognita infection. The temporal gene expression analysis showed that 3 days after inoculation with M. incognita, the CYP710A11 expression was significantly suppressed in the tomato roots, while a significant decrease in the stigmasterol content was observed after 14 days. A cyp710a11 knockout mutant tomato line lacking stigmasterol was analyzed to better understand the role of CYP710A11 in nematode development. M. incognita grown in the mutant line showed reduced egg mass counts, presumably due to the impaired growth of the mutant. However, the nematodes developed as well as they did in the wild-type line. Thus, while the suppression of CYP710A11 expression during nematode development may be a defense response of the plant against the nematode, the lack of stigmasterol did not seem to affect the nematode. This study contributes to the understanding of the role of stigmasterol in the interaction between M. incognita and tomato plants and shows that the sterol C-22 desaturase is not essential for the success of M. incognita.