Search

Tomato is one of the major economically domesticated crops, and it is extensively used in different ways and purposes worldwide. Cell metabolism is the central core of all the biological processes to sustain life including cell growth, differentiation, maintenance, and response to environmental stress. To evaluate how genetic engineering can improve tomato fruit metabolome, the transcriptomic and metabolomic datasets of two transgenic tomatoes (SlMX1 overexpression and RNAi lines) have been compared with wild-type. The combined results demonstrated that the constitutive expression of SlMX1 not only increased trichome formation, carotenoids, and terpenoids as has been stated in several studies, but has also up- and down-regulated the expression of multiple genes related to cell growth (cell wall turnover), primary (carbohydrates, vitamins, and phytohormones), and secondary (phenylpropanoids, carotenoids, and terpenoids) metabolism, cell signaling, and stress responses. These changes in gene expression due to the constitutive expression of SlMX1 promote the most important agroeconomic traits such as fruit yield and quality, biosynthesis of health-promoting phytochemicals (including phenolic acids, flavonoids, and anthocyanins), and finally, activate resistance to Botrytis cinerea and repress the expression of over-ripening-related genes, thus extending the fruit shelf-life. In conclusion, the traits improvement achieved by SlMX1 overexpression can be harnessed in molecular breeding programs to engineer fruit size and yield, induce health-promoting secondary metabolites, promote fungal resistance, and finally extend the fruit shelf-life.

Salt stress hinders plant growth and disrupts many physio-biochemical and molecular processes. The present study evaluated the potential role of foliar applied 24-epibrassinolide (EBR) for mitigating the adverse effects of salinity in rice plants. Our findings showed that salt stress reduced several growth and physiological parameters, and substantially increased oxidative stress in rice seedlings. The foliar application of EBR replenished the negative effects of salt stress by improving plant growth and physiological attributes in rice plants. Moreover, application of EBR substantially reduced oxidative injuries by enhancing antioxidant enzymes and phenolic compounds in rice plants during salt stress. Interestingly, the endogenous ABA levels were declined in stressed plants by EBR treatment, also validated by expression analysis of ABA-related genes. In addition, application of EBR upregulated carotenoids and flavonoids pathway genes, thus showing its function to activate secondary metabolism in rice plants during salt stress. The principal component analysis (PCA) indicated that, under salt stress, the response of EBR-treated rice plants was strongly correlated with the accumulation of phenolic compounds and flavonoids. Collectively, this study presents useful insight into the distinct role of EBR by activating underlying enzymatic and non-enzymatic defense mechanisms to mitigate salinity in rice plants.