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Improving nutritional fruit quality and impacts important agro-traits such as biotic or abiotic stresses are extremely important for human civilization. Our previous study reported that manipulation of SlMX1 gene enhanced carotenoids accumulation and drought resistance in tomato. Here, RNA-Seq analysis proved to be a very useful tool to provide insights into the regulatory mechanisms of SlMX1 involved in stress resistance and enhanced secondary metabolites. Physiological analysis showed that over-expression of SlMX1 results in substantially increased broad-spectrum tolerance to a wide-range of abiotic and biotic (fungus, bacteria, virus and insects) stresses in tomato. This research appears to be of remarkable interest because enhanced terpenoids content has been achieved by increasing trichome density. In addition, we reported two types of trichome which seems to be aberrant types in tomato. This study unravels the mechanism of regulation of SlMX1, which simultaneously modulates resistance and metabolic processes through regulating key structural and regulatory genes of the corresponding pathways.

Plants are the ultimate source of nutrients in the human diet. To ensure adequate availability of high quality food for an increasing world population, traits including improved tolerance of stresses and nutrient levels need to be selected in crops, both individually and in combination. Here we report the identification of SlMX1 encoding a MIXTA-like MYB transcription factor in tomato that simultaneously modulates drought resistance and metabolic processes through regulating key structural and regulatory genes of the corresponding pathways. Over-expression of SlMX1 results in substantially increased drought tolerance and improved fruit quality, while knocking down SlMX1 resulted in the opposite phenotypes. Our study indicates an effective way with multiple beneficial traits by genetic engineering of a single regulatory gene and can be a novel approach to breeding crops.

Citrus is a perennial woody crop of global economic importance. However, the regulatory mechanism of fruit ripening in citrus remains poorly understood. To explore the regulatory roles of transcription factors in fruit ripening, CgDREB ( d ehydration r esponsive e lement b inding) gene was characterized and was functionally overexpressed in tomato ( Solanum lycopersicum, cv. Ailsa Craig), resulting in smaller fruit size. Therefore, two independent lines with the highest expression of CgDREB were selected to study the metabolite profile in the flesh and peel of tomato fruits during ripening using gas chromatography–mass spectrometry. The results revealed that the levels of organic acids and sugars generally increased in both the flesh and peel of tomato. In addition, a significant increase of ethylene production was observed at the breaker stage, indicating a strong correlation between fruit ripening and ethylene release. Taken together, our results provide insights into the important role of CgDREB gene in regulating fruit ripening properties.