Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pa...Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pathogens, insects and other plant pests and some are toxic to humans at high levels. Although the levels of FCs in grapefruits are non-toxic to humans, they inhibit the intestinal enzyme CYP3A, thus preventing degradation of medicines, such as statins, and causing dangerous overdose effects. This overdosing can cause devastating side effects, ranging from stomach bleeding to kidney problems, muscle aches and irregular heartbeats. In the present study, we utilize LC/MS to characterize the levels of FCs pathway intermediates and end products in twelve citrus cultivars, including mandarin (Citrus reticulata), orange [Citrus sinensis (L.) Osbeck], Pummelo [Citrus maxima (Burm.) Merr.], grapefruit (Citrus paradisi Macf.), and two newly selected grapefruit like varieties [(Citrus reticulate) X [Citrus maxima (Burm.) Merr]. The orange and mandarin varieties do not contain FCs or FCs precursor compounds suggesting that this biosynthetic pathway is absent or inactive in mandarins and oranges and therefore a good genetic source for null alleles to FCs biosynthesis. We report the selection and characterization of two new low FCs and seedless grapefruit-like varieties, “Aliza” and “Coocki”, developed by a cross between pummelo and mandarin. Fruits of these varieties resemble grapefruit and contain high levels of the flavanone naringin, typical of grapefruit, but contain only trace amounts of FCs (based on LCMS analysis). Based on the variability of FCs content and inheritance in citrus species, the results suggest that future development of new low-FCs grapefruit varieties is an achievable objective.展开更多
Mango fruit exposed to sunlight develops red skin and are more resistant to biotic and abiotic stresses.Here we show that harvested red mango fruit that was exposed to sunlight at the orchard is more resistant than gr...Mango fruit exposed to sunlight develops red skin and are more resistant to biotic and abiotic stresses.Here we show that harvested red mango fruit that was exposed to sunlight at the orchard is more resistant than green fruit to Colletotrichum gloeosporioides.LCMS analysis showed high amounts of antifungal compounds,as glycosylated flavonols,glycosylated anthocyanins,and mangiferin in red vs.green mango skin,correlated with higher antioxidant and lower ROS.However,also the green side of red mango fruit that has low levels of flavonoids was resistant,indicated induced resistance.Transcriptomes of red and green fruit inoculated on their red and green sides with C.gloeosporioides were analyzed.Overall,in red fruit skin,2,187 genes were upregulated in response to C.gloeosporioides.On the green side of red mango,upregulation of 22 transcription factors and 33 signaling-related transcripts indicated induced resistance.The RNA-Seq analysis suggests that resistance of the whole red fruit involved upregulation of ethylene,brassinosteroid,and phenylpropanoid pathways.To conclude,red fruit resistance to fungal pathogen was related to both flavonoid toxicity and primed resistance of fruit that was exposed to light at the orchard.展开更多
文摘Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pathogens, insects and other plant pests and some are toxic to humans at high levels. Although the levels of FCs in grapefruits are non-toxic to humans, they inhibit the intestinal enzyme CYP3A, thus preventing degradation of medicines, such as statins, and causing dangerous overdose effects. This overdosing can cause devastating side effects, ranging from stomach bleeding to kidney problems, muscle aches and irregular heartbeats. In the present study, we utilize LC/MS to characterize the levels of FCs pathway intermediates and end products in twelve citrus cultivars, including mandarin (Citrus reticulata), orange [Citrus sinensis (L.) Osbeck], Pummelo [Citrus maxima (Burm.) Merr.], grapefruit (Citrus paradisi Macf.), and two newly selected grapefruit like varieties [(Citrus reticulate) X [Citrus maxima (Burm.) Merr]. The orange and mandarin varieties do not contain FCs or FCs precursor compounds suggesting that this biosynthetic pathway is absent or inactive in mandarins and oranges and therefore a good genetic source for null alleles to FCs biosynthesis. We report the selection and characterization of two new low FCs and seedless grapefruit-like varieties, “Aliza” and “Coocki”, developed by a cross between pummelo and mandarin. Fruits of these varieties resemble grapefruit and contain high levels of the flavanone naringin, typical of grapefruit, but contain only trace amounts of FCs (based on LCMS analysis). Based on the variability of FCs content and inheritance in citrus species, the results suggest that future development of new low-FCs grapefruit varieties is an achievable objective.
基金The Chief Scientist of the Ministry of Agriculture and Rural Development(Grant no.20-14-0019).
文摘Mango fruit exposed to sunlight develops red skin and are more resistant to biotic and abiotic stresses.Here we show that harvested red mango fruit that was exposed to sunlight at the orchard is more resistant than green fruit to Colletotrichum gloeosporioides.LCMS analysis showed high amounts of antifungal compounds,as glycosylated flavonols,glycosylated anthocyanins,and mangiferin in red vs.green mango skin,correlated with higher antioxidant and lower ROS.However,also the green side of red mango fruit that has low levels of flavonoids was resistant,indicated induced resistance.Transcriptomes of red and green fruit inoculated on their red and green sides with C.gloeosporioides were analyzed.Overall,in red fruit skin,2,187 genes were upregulated in response to C.gloeosporioides.On the green side of red mango,upregulation of 22 transcription factors and 33 signaling-related transcripts indicated induced resistance.The RNA-Seq analysis suggests that resistance of the whole red fruit involved upregulation of ethylene,brassinosteroid,and phenylpropanoid pathways.To conclude,red fruit resistance to fungal pathogen was related to both flavonoid toxicity and primed resistance of fruit that was exposed to light at the orchard.
