Mechanistic Investigations of 1-Aminocyclopropane 1-Carboxylic Acid Oxidase with Alternate Cyclic and Acyclic Substrates†

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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New Derivatives of 3,4-Dihydroisoquinoline-3-carboxylic Acid with Free-Radical Scavenging, D-Amino Acid Oxidase, Acetylcholinesterase and Butyrylcholinesterase Inhibitory Activity

Molecules ◽

10.3390/molecules191015866 ◽

2014 ◽

Vol 19 (10) ◽

pp. 15866-15890 ◽

Cited By ~ 4

Author(s):

Jolanta Solecka ◽

Adam Guśpiel ◽

Magdalena Postek ◽

Joanna Ziemska ◽

Robert Kawęcki ◽

...

Keyword(s):

Free Radical ◽

Amino Acid ◽

Carboxylic Acid ◽

Inhibitory Activity ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Acid Oxidase ◽

Amino Acid Oxidase ◽

Derivatives Of

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Potamogeton pectinatus Is Constitutively Incapable of Synthesizing Ethylene and Lacks 1-Aminocyclopropane-1-Carboxylic Acid Oxidase

PLANT PHYSIOLOGY ◽

10.1104/pp.111.3.901 ◽

1996 ◽

Vol 111 (3) ◽

pp. 901-908 ◽

Cited By ~ 21

Author(s):

J. E. Summers ◽

LACJ. Voesenek ◽

CWPM. Blom ◽

M. J. Lewis ◽

M. B. Jackson

Keyword(s):

Carboxylic Acid ◽

Potamogeton Pectinatus ◽

Acid Oxidase

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

Molecules ◽

10.3390/molecules24061128 ◽

2019 ◽

Vol 24 (6) ◽

pp. 1128 ◽

Cited By ~ 2

Author(s):

Yanhua Tu ◽

Beixuan He ◽

Songyan Gao ◽

Dandan Guo ◽

Xinlei Jia ◽

...

Keyword(s):

Carboxylic Acid ◽

Biosynthetic Pathway ◽

Metabolic Flux ◽

Cellular Level ◽

Vital Role ◽

Acid Oxidase ◽

Hydroxysafflor Yellow A ◽

Flavonoid Biosynthetic Pathway ◽

Varying Environments ◽

Plant Acclimatization

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.

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