Increased Sucrose in the Hypocotyls of Radish Sprouts Contributes to Nitrogen Deficiency-Induced Anthocyanin Accumulation

Abstract

Effects of nitrogen (N) deficiency and sucrose (Suc) addition on regulation of anthocyanin biosynthesis and their relationship were investigated in this study. Radish sprouts subjected to N deficiency had 50% higher anthocyanin accumulation than when grown in Hoagland solution (a nutrient medium with all macronutrients). The contents of endogenous soluble sugars (Suc, fructose, and glucose) in the hypocotyls were also markedly increased by N limitation, with Suc showing the highest increase. Inhibition of carbohydrate biosynthesis by addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) also eliminated N deficiency-induced anthocyanin accumulation. The latter was further supported by the expression of anthocyanin biosynthesis related genes and decreased activities of nitrate reductase in the presence of Suc. Together our results indicate that N deficiency-induced anthocyanin accumulation was, at least partly, dependent on the increase of the soluble sugar, especially Suc. This work is the first comprehensive study on relationship between N deficiency and sugar content on anthocyanin accumulation in the hypocotyls of radish sprouts.

Role of sucrose in modulating the low‐nitrogen‐induced accumulation of phenolic compounds in lettuce (Lactuca sativa L.)

“…In particular, low nitrogen availability has been shown to significantly increase the accumulation of phenolic compounds by regulating the expression of major enzymes related to phenolic biosynthesis and positive and negative transcription factors, such as MYBs. 8,12,13 We have previously shown that cultivation under low nitrogen conditions increases the transcriptional levels of genes or enzyme activities related to the phenolic synthesis pathway in lettuce, resulting in higher phenolic accumulation. [14][15][16] Interestingly, reduction of nitrogen supply may also have human and environmental benefits through decreasing the nitrate accumulation in vegetables and limiting nitrogen loss in the environment, respectively.…”

“…[17][18][19] Several studies have found that the foliar or root application of Suc can significantly increase the accumulation of phenolic compounds in plants, which was linked to changes in the expression of genes involved in phenolic biosynthesis. 12,[20][21][22] Interestingly, increased Suc production has frequently been observed in plants grown in low-nitrogen conditions. 12,[23][24][25] Taken together, these results suggest that Suc may play an important role in regulating the low-nitrogeninduced accumulation of phenolic compounds in vegetables.…”

“…12,[20][21][22] Interestingly, increased Suc production has frequently been observed in plants grown in low-nitrogen conditions. 12,[23][24][25] Taken together, these results suggest that Suc may play an important role in regulating the low-nitrogeninduced accumulation of phenolic compounds in vegetables.…”

MdATG18a overexpression improves tolerance to nitrogen deficiency and regulates anthocyanin accumulation through increased autophagy in transgenic apple

“…positively regulates anthocyanin structural genes (Wan, Zhang, Song, Tian, & Yao, ). In the hypocotyls of Raphanus sativus , an increase in the level of soluble sugars, especially sucrose, contributes to an accumulation of anthocyanin that results from an N‐deficit (Su, Wu, & Jin, ).…”

Sugar Signaling Under Abiotic Stress in Plants

“…Nitrogen deficiency impairs plant growth, whereas photosynthesis may still occur at a relatively high rate. For example, sugar accumulation was reported for barley leaves (Wang and Tillberg, 1996), barley seedlings (Comadira et al, 2015), and radish hypocotyls (Su et al, 2016) under N deficiency. Also phosphorus, potassium, and magnesium deficiencies were found to result in Suc accumulation in leaves, in parallel with a decrease of this sugar in phloem, which is indicative of growth impairment (Marschner et al, 1996).…”