Water Deficit Affected Flavonoid Accumulation by Regulating Hormone Metabolism in Scutellaria baicalensis Georgi Roots

Abstract

The content of flavonoids especially baicalin and baicalein determined the medical quality of Scutellaria baicalensis which is a Chinese traditional medicinal plant. Here, we investigated the mechanism responsible for the content and composition of flavonoids in S. baicalensis under water deficit condition. The transcription levels of several genes which are involved in flavonoid biosynthesis were stimulated by water deficit. Under water deficit condition, fifteen up-regulated proteins, three down-regulated proteins and other six proteins were detected by proteomic analysis. The identified proteins include three gibberellin (GA)- or indoleacetic acid (IAA)-related proteins. Decreased endogenous GAs level and increased IAA level were observed in leaves of S. baicalensis which was treated with water deficit. Exogenous application of GA or α-naphthalene acelic acid (NAA) to plants grown under water deficit conditions led to the increase of endogenous GAs and the decrease of IAA and flavonoids, respectively. When the synthesis pathway of GA or IAA in plants was inhibited by application with the inhibitors, flavonoid levels were recovered. These results indicate that water deficit affected flavonoid accumulation might through regulating hormone metabolism in S. baicalensis Georgi.

Role of Temperature and Soil Moisture Conditions on Flavonoid Production and Biosynthesis-Related Genes in Ginkgo (Ginkgo biloba L.) Leaves

“…Similar observations of PAL increased expression were reported after exposure to low temperature in Arabidopsis thaliana leaves [30] and tomato (Solanum lycopersicum) plants [31]. Additionally, the unclear role of moisture effect on PAL gene expression was also supported by the conflicting observations in Camellia sinensis [32] and Scutellaria baicalensis [33] which showed decreased and increased PAL expression under water deficit conditions, respectively.…”

“…Suzanne) [31] showing increased CHS expression in response to lower temperatures. Our results also demonstrated the presence of consistent relationship between soil moisture and C4H expression and flavonoid content (i.e., higher expression under lower soil moisture) as well as the lack of relationship for CHS as expression was higher under high soil moisture, results are at variance with what has been reported in Camellia sinensis [32] and Scutellaria baicalensis [33] in which increased expression was reported under water deficit.…”

A Scutellaria baicalensis R2R3-MYB gene, SbMYB8, regulates flavonoid biosynthesis and improves drought stress tolerance in transgenic tobacco

“…The protein level of a putative R2R3-MYB transcription factor in S. baicalensis roots was increased under water deficit condition, and this R2R3-MYB is also involved in flavonoid biosynthesis in S. baicalensis under stress (Yuan et al 2012). GA 3 treatment increased the expression of SbMYB8 which have the similar expression pattern with SbCHS and SbC4H, indicating that SbMYB8 might be involved in the flavonoid biosynthesis in S. baicalensis based on subgroup classification and co-expression analysis (Yuan et al 2013b).…”

Development and validation of an HPLC-DAD analytical method to quantify 5-methoxyflavones in methanolic extracts of Vochysia divergens Pohl cultured under stress conditions

“…28 In another approach, Guidi and collaborators confirmed that water stress and solar irradiance affected the physiology and the concentrations of non-structural carbohydrates and phenylpropanoids in Ligustrum vulgare. 29 Yuan et al, 30 observed decreased levels of endogenous gibberellic acid (GA) and increased levels of indol acetic acid (IAA) in the leaves of Scutellaria baicalensis treated under conditions of water deficit. The water deficit probably affected the accumulation of flavonoids by regulating the metabolism of hormones in S. baicalensis.…”

“…The water deficit probably affected the accumulation of flavonoids by regulating the metabolism of hormones in S. baicalensis. 30 The development of endophytic symbiosis can help plants in terms of the composition of mineral nutrients, fixation of N 2 , hormonal balance, physical modification of the soil, and protection of the host against biotic and abiotic stress. 11,31 Beneficial plant-associated microorganisms may enhance resistance to abiotic stress among other factors, 31 but understanding of the relationship between endophytic fungi and their host plants is still very limited, and many symbiotic systems can only be understood in the context of natural adversity of the host.…”