scholarly journals CtACO1 Overexpression Resulted in the Alteration of the Flavonoids Profile of Safflower

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1128 ◽  
Author(s):  
Yanhua Tu ◽  
Beixuan He ◽  
Songyan Gao ◽  
Dandan Guo ◽  
Xinlei Jia ◽  
...  

Background: Flavonoids with various structures play a vital role in plant acclimatization to varying environments as well as in plant growth, development, and reproduction. Exogenous applications of ethylene and 1-aminocyclopropane carboxylic acid (ACC), could affect the accumulation of flavonoids. Very few attempts have been made to investigate the effect of 1-aminocyclopropane carboxylic acid oxidase (ACO), a unique enzyme that catalyzes ACC to ethylene, on genes and metabolites in the flavonoid biosynthetic pathway. In this study, two ACOs in safflower (CtACOs) were cloned, and then transgenic safflower with overexpressed CtACO1 was generated through the Agrobacterium-mediated floral dipping method. Results: CtACO1 and CtACO2 were both characterized by the 2-oxoglutarate binding domain RxS and the ferrous iron binding site HxDxnH as ACOs from other plants. However, the transcript levels of CtACO1 in flowers at stages I, II, III, and IV were all higher than those of CtACO2. At the cellular level, by using electroporation transformation, CtACO1 was found to be localized at the cytomembrane in onion epidermal cells. CtACO1 overexpression had varying effects on genes involved in the ethylene and flavonoid biosynthetic pathways. The metabolites analysis showed that CtACO1 overexpression lines had a higher accumulation of quercetin and its glycosylated derivatives (quercetin 3-β-d-glucoside and rutin). In contrast, the accumulation of quinochalcones (hydroxysafflor yellow A and carthamin), kaempferol glycosylated derivatives (kaempferol-3-O-β-rutinoside and kaempferol-3-O-β-d-glucoside), apigenin, and luteolin in CtACO1 overexpression lines were decreased. Conclusion: This study confirmed the feasibility of applying the floral dipping method to safflower and showed a novel regulatory effect of CtACO1 in the flavonoid biosynthetic pathway. It provides hypothetical and practical groundwork for further research on regulating the overall metabolic flux of flavonoids in safflower, particularly hydroxysafflor yellow A and other quinochalcones, by using appropriate genetic engineering strategies.

2021 ◽  
Vol 12 ◽  
Author(s):  
Ghulam Kubra ◽  
Maryam Khan ◽  
Faiza Munir ◽  
Alvina Gul ◽  
Tariq Shah ◽  
...  

Drought is one of the hostile environmental stresses that limit the yield production of crop plants by modulating their growth and development. Peanut (Arachis hypogaea) has a wide range of adaptations to arid and semi-arid climates, but its yield is prone to loss due to drought. Other than beneficial fatty acids and micronutrients, peanut harbors various bioactive compounds including flavonoids that hold a prominent position as antioxidants in plants and protect them from oxidative stress. In this study, understanding of the biosynthesis of flavonoids in peanut under water deficit conditions was developed through expression analysis and correlational analysis and determining the accumulation pattern of phenols, flavonols, and anthocyanins. Six peanut varieties (BARD479, BARI2011, BARI2000, GOLDEN, PG1102, and PG1265) having variable responses against drought stress have been selected. Higher water retention and flavonoid accumulation have been observed in BARI2011 but downregulation has been observed in the expression of genes and transcription factors (TFs) which indicated the maintenance of normal homeostasis. ANOVA revealed that the expression of flavonoid genes and TFs is highly dependent upon the genotype of peanut in a spatiotemporal manner. Correlation analysis between expression of flavonoid biosynthetic genes and TFs indicated the role of AhMYB111 and AhMYB7 as an inhibitor for AhF3H and AhFLS, respectively, and AhMYB7, AhTTG1, and AhCSU2 as a positive regulator for the expression of Ah4CL, AhCHS, and AhF3H, respectively. However, AhbHLH and AhGL3 revealed nil-to-little relation with the expression of flavonoid biosynthetic pathway genes. Correlational analysis between the expression of TFs related to the biosynthesis of flavonoids and the accumulation of phenolics, flavonols, and anthocyanins indicated coregulation of flavonoid synthesis by TFs under water deficit conditions in peanut. This study would provide insight into the role of flavonoid biosynthetic pathway in drought response in peanut and would aid to develop drought-tolerant varieties of peanut.


Author(s):  
Zhi-Jiao Sun ◽  
Jia-Zhang Lian ◽  
Li Zhu ◽  
Yi-Qi Jiang ◽  
Guo-Si Li ◽  
...  

Ergosterol, a terpenoid compound produced by fungi, is an economically important metabolite serving as the direct precursor of steroid drugs. Herein, ergsosterol biosynthetic pathway modification combined with storage capacity enhancement was proposed to synergistically improve the production of ergosterol in Saccharomyces cerevisiae. S. cerevisiae strain S1 accumulated the highest amount of ergosterol [7.8 mg/g dry cell weight (DCW)] among the wild-type yeast strains tested and was first selected as the host for subsequent metabolic engineering studies. Then, the push and pull of ergosterol biosynthesis were engineered to increase the metabolic flux, overexpression of the sterol acyltransferase gene ARE2 increased ergosterol content to 10 mg/g DCW and additional overexpression of a global regulatory factor allele (UPC2-1) increased the ergosterol content to 16.7 mg/g DCW. Furthermore, considering the hydrophobicity sterol esters and accumulation in lipid droplets, the fatty acid biosynthetic pathway was enhanced to expand the storage pool for ergosterol. Overexpression of ACC1 coding for the acetyl-CoA carboxylase increased ergosterol content from 16.7 to 20.7 mg/g DCW. To address growth inhibition resulted from premature accumulation of ergosterol, auto-inducible promoters were employed to dynamically control the expression of ARE2, UPC2-1, and ACC1. Consequently, better cell growth led to an increase of ergosterol content to 40.6 mg/g DCW, which is 4.2-fold higher than that of the starting strain. Finally, a two-stage feeding strategy was employed for high-density cell fermentation, with an ergosterol yield of 2986.7 mg/L and content of 29.5 mg/g DCW. This study provided an effective approach for the production of ergosterol and other related terpenoid molecules.


2021 ◽  
Vol 22 (23) ◽  
pp. 12824
Author(s):  
Weixin Liu ◽  
Yi Feng ◽  
Suhang Yu ◽  
Zhengqi Fan ◽  
Xinlei Li ◽  
...  

Flavonoids are an important class of secondary metabolites widely found in plants, contributing to plant growth and development and having prominent applications in food and medicine. The biosynthesis of flavonoids has long been the focus of intense research in plant biology. Flavonoids are derived from the phenylpropanoid metabolic pathway, and have a basic structure that comprises a C15 benzene ring structure of C6-C3-C6. Over recent decades, a considerable number of studies have been directed at elucidating the mechanisms involved in flavonoid biosynthesis in plants. In this review, we systematically summarize the flavonoid biosynthetic pathway. We further assemble an exhaustive map of flavonoid biosynthesis in plants comprising eight branches (stilbene, aurone, flavone, isoflavone, flavonol, phlobaphene, proanthocyanidin, and anthocyanin biosynthesis) and four important intermediate metabolites (chalcone, flavanone, dihydroflavonol, and leucoanthocyanidin). This review affords a comprehensive overview of the current knowledge regarding flavonoid biosynthesis, and provides the theoretical basis for further elucidating the pathways involved in the biosynthesis of flavonoids, which will aid in better understanding their functions and potential uses.


2019 ◽  
Vol 20 (5) ◽  
pp. 1047 ◽  
Author(s):  
Jian Yu ◽  
Lijuan Niu ◽  
Jihua Yu ◽  
Weibiao Liao ◽  
Jianming Xie ◽  
...  

Calcium and ethylene are essential in plant growth and development. In this study, we investigated the effects of calcium and ethylene on adventitious root formation in cucumber explants under salt stress. The results revealed that 10 μM calcium chloride (CaCl2) or 0.1 μM ethrel (ethylene donor) treatment have a maximum biological effect on promoting the adventitious rooting in cucumber under salt stress. Meanwhile, we investigated that removal of ethylene suppressed calcium ion (Ca2+)-induced the formation of adventitious root under salt stress indicated that ethylene participates in this process. Moreover, the application of Ca2+ promoted the activities of 1-aminocyclopropane-l-carboxylic acid synthase (ACS) and ACC Oxidase (ACO), as well as the production of 1-aminocyclopropane-l-carboxylic acid (ACC) and ethylene under salt stress. Furthermore, we discovered that Ca2+ greatly up-regulated the expression level of CsACS3, CsACO1 and CsACO2 under salt stress. Meanwhile, Ca2+ significantly down-regulated CsETR1, CsETR2, CsERS, and CsCTR1, but positively up-regulated the expression of CsEIN2 and CsEIN3 under salt stress; however, the application of Ca2+ chelators or channel inhibitors could obviously reverse the effects of Ca2+ on the expression of the above genes. These results indicated that Ca2+ played a vital role in promoting the adventitious root development in cucumber under salt stress through regulating endogenous ethylene synthesis and activating the ethylene signal transduction pathway.


2019 ◽  
Vol 20 (15) ◽  
pp. 3731 ◽  
Author(s):  
Emilia Wilmowicz ◽  
Agata Kućko ◽  
Sebastian Burchardt ◽  
Tomasz Przywieczerski

The drought is a crucial environmental factor that determines yielding of many crop species, e.g., Fabaceae, which are a source of valuable proteins for food and feed. Herein, we focused on the events accompanying drought-induced activation of flower abscission zone (AZ)—the structure responsible for flower detachment and, consequently, determining seed production in Lupinus luteus. Therefore, detection of molecular markers regulating this process is an excellent tool in the development of improved drought-resistant cultivars to minimize yield loss. We applied physiological, molecular, biochemical, immunocytochemical, and chromatography methods for a comprehensive examination of changes evoked by drought in the AZ cells. This factor led to significant cellular changes and activated AZ, which consequently increased the flower abortion rate. Simultaneously, drought caused an accumulation of mRNA of genes inflorescence deficient in abscission-like (LlIDL), receptor-like protein kinase HSL (LlHSL), and mitogen-activated protein kinase6 (LlMPK6), encoding succeeding elements of AZ activation pathway. The content of hydrogen peroxide (H2O2), catalase activity, and localization significantly changed which confirmed the appearance of stressful conditions and indicated modifications in the redox balance. Loss of water enhanced transcriptional activity of the abscisic acid (ABA) and ethylene (ET) biosynthesis pathways, which was manifested by elevated expression of zeaxanthin epoxidase (LlZEP), aminocyclopropane-1-carboxylic acid synthase (LlACS), and aminocyclopropane-1-carboxylic acid oxidase (LlACO) genes. Accordingly, both ABA and ET precursors were highly abundant in AZ cells. Our study provides information about several new potential markers of early response on water loss, which can help to elucidate the mechanisms that control plant response to drought, and gives a useful basis for breeders and agronomists to enhance tolerance of crops against the stress.


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