gibberellins
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Potato represents the third most important crop worldwide and therefore to understand regulations of tuber onset is crucial from both theoretical and practical points of view. Photosynthesis and related carbohydrate status along with phytohormone balance belong to the essential factors in regulation of plant development including storage organ formation. In our work we used potato (Solanum tuberosum) cv. Lada and its spontaneously tuberizing mutant (ST plants) grown in vitro under low carbohydrate availability (non-inductive conditions). Small plant phenotype and readiness to tuberization of ST plants was, however, not accompanied by lower gibberellins levels, as determined by UHPLC-MS/MS. Therefore, we focused on the other inducing factor, carbohydrate status. Using HPLC, we followed changes in carbohydrate distribution under mixotrophic (2.5% sucrose in medium) and photoautotrophic conditions (no sucrose addition and higher gas and light availability) and observed changes in soluble carbohydrate allocation and starch deposition, favouring basal stem part in mutants. In addition, the determination of tuber-inducing marker gene expressions revealed increased levels of StSP6A in ST leaves. Collectively these data point towards the possibility of two parallel cross-talking pathways (carbohydrate - and gibberellin- dependent ones) with the power of both to outcompete the other one when its signal is for some reason extraordinary strong.
- MeSH
- geneticky modifikované rostliny genetika metabolismus MeSH
- gibereliny metabolismus MeSH
- hlízy rostlin genetika metabolismus MeSH
- metabolismus sacharidů genetika fyziologie MeSH
- regulace genové exprese u rostlin genetika fyziologie MeSH
- rostlinné proteiny genetika metabolismus MeSH
- Solanum tuberosum genetika metabolismus MeSH
- tandemová hmotnostní spektrometrie MeSH
- Publikační typ
- časopisecké články MeSH
We studied the effect of reducing the levels of the mitochondrial electron carrier cytochrome c (CYTc) in Arabidopsis thaliana. Plants with CYTc deficiency have delayed growth and development, and reach flowering several days later than the wild-type but with the same number of leaves. CYTc-deficient plants accumulate starch and glucose during the day, and contain lower levels of active gibberellins (GA) and higher levels of DELLA proteins, involved in GA signaling. GA treatment abolishes the developmental delay and reduces glucose accumulation in CYTc-deficient plants, which also show a lower raise in ATP levels in response to glucose. Treatment of wild-type plants with inhibitors of mitochondrial energy production limits plant growth and increases the levels of DELLA proteins, thus mimicking the effects of CYTc deficiency. In addition, an increase in the amount of CYTc decreases DELLA protein levels and expedites growth, and this depends on active GA synthesis. We conclude that CYTc levels impinge on the activity of the GA pathway, most likely through changes in mitochondrial energy production. In this way, hormone-dependent growth would be coupled to the activity of components of the mitochondrial respiratory chain.
- MeSH
- Arabidopsis růst a vývoj metabolismus MeSH
- cytochromy c nedostatek metabolismus fyziologie MeSH
- energetický metabolismus MeSH
- gibereliny metabolismus fyziologie MeSH
- glukosa metabolismus MeSH
- homeostáza MeSH
- mitochondrie metabolismus MeSH
- proteiny huseníčku metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- škrob metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A robust, reliable and high-throughput method for extraction and purification of gibberellins (GAs), a group of tetracyclic diterpenoid carboxylic acids that include endogenous growth hormones, from plant material was developed. The procedure consists of two solid-phase extraction steps (Oasis(®) MCX-HLB and Oasis(®) MAX) and gives selective enrichment and efficient clean-up of these compounds from complex plant extracts. The method was tested with plant extracts of Brassica napus and Arabidopsis thaliana, from which total recovery of internal standards of about 72% was achieved. A rapid baseline chromatographic separation of 20 non-derivatised GAs by ultra performance liquid chromatography is also presented where a reversed-phase chromatographic column Acquity CSH(®) and a mobile phase consisting of methanol and aqueous 10mM-ammonium formate is used. This method enables sensitive and precise quantitation of GAs by MS/MS in multiple-reaction monitoring mode (MRM) by a standard isotope dilution method. Optimal conditions, including final flow rate, desolvation temperature, desolvation gas flow, capillary and cone voltage for effective ionisation in the electrospray ion source were found. All studied GAs were determined as free acids giving dominant quasi-molecular ions of [M-H](-) with limits of detection ranging between 0.08 and 10 fmol and linear ranges over four orders of magnitude. Taking advantage of highly effective chromatographic separation of 20 GAs and very sensitive mass spectrometric detection, the presented bioanalytical method serves as a useful tool for plant biologists studying the physiological roles of these hormones in plant development.
- MeSH
- Arabidopsis chemie MeSH
- Brassica napus chemie MeSH
- chromatografie kapalinová metody MeSH
- extrakce na pevné fázi MeSH
- gibereliny analýza MeSH
- květy chemie MeSH
- rostlinné extrakty analýza MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- výhonky rostlin chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Termínem gibberellin-regulated proteins je označována skupina alergenů zkoumaná v posledních letech v souvislosti se zkříženými pylově potravinovými alergiemi (pollen/food allergy syndrome). Gibereliny jsou skupinou fytohormonů figurující v ochraně rostlin, mají baktericidní, virucidní a fungicidní účinky. Fungují jako růstové hormony a vylučují se při zrání, ale i při stresu rostlin. Jedná se o antimikrobiální peptidy o molekulové hmotnosti 7–8 kDa bohaté na cystein, jejichž struktura je obdobná v celé řadě vyšších rostlin. Díky vysokému obsahu cysteinu jsou termostabilní a acidorezistentní, proto jsou považovány za rizikové potravinové alergeny, schopné vyvolat závažné alergické reakce. Klinické projevy potravinové alergie na gibberellin-regulated proteiny jsou poměrně charakteristické, jsou jimi otok obličeje (zvláště očních víček) a laryngeální otok. Alergické reakce bývají se závažnějším průběhem zvláště tehdy, pokud jsou přítomny další faktory (tělesná náma- ha, léčba nesteroidními antiflogistiky, inhibitory proteinové pumpy, vliv alkoholu, infekce, menstruace apod.). Dosud bylo identifikováno 9 těchto alergenních proteinů různých rostlinných zdrojů pylových Cry j 7, Cup s 7, Jun a 7, potravinových Pru p 7, Pru m 7, Pun g 7, Cit s 7, Pru av 7, Cap a 7. Byly popsány i dvě nealergenní molekuly – applemaclein, snakin-1. K primární senzibilizaci dochází nejspíše prostřednictvím inhalační alergie na pyl cypřišovitých.
Gibberellin-regulated proteins are a group of allergens investigated in recent years in relation with pollen/food allergy syndrome. Gibberellins are a group of phytohormones, which play role in plant protection, have bactericidal, virucidal and fungicidal effects, function as growth hormones and are secreted during ripening process, but also during plant stress. These proteins are antimicrobial peptides with a molecular weight of 7–8 kDa, rich in cysteine, which stucture is very conserved across a wide number of higher plants. Due to their high cysteine content, they are thermostable and acidoresistant, which is why they are considered as a risky food allergens capable of causing serious allergic reactions. Clinical symptoms of gibberellin-regulated proteins allergy are quite characteristic, including facial swelling (especially eyelid oedema) a laryngeal tightness. Allergic reactions to GRPs tend to be more severe, especially if co-factors are present (exercise, nonsteroid – antiinflammatory drugs or proton pump inhibitors therapy, alcohol, infection, menstruation and others). So far 9 allergenic gibberellin-regulated proteins have been identified from different plant sources pollen Cry j 7, Cup s 7, Jun a 7 and food Pru p 7, Pru m 7, Pun g 7, Cit s 7, Pru av 7, Cap a 7 and 2 non-allergenic applemaclein, snakin-1. Most probably primary sensitization occurs through inha- lation allergy to cypress pollen.
In cereal grains, the maternal nucellar projection (NP) constitutes the link to the filial organs, forming a transfer path for assimilates and signals towards the endosperm. At transition to the storage phase, the NP of barley (Hordeum vulgare) undergoes dynamic and regulated differentiation forming a characteristic pattern of proliferating, elongating, and disintegrating cells. Immunolocalization revealed that abscisic acid (ABA) is abundant in early non-elongated but not in differentiated NP cells. In the maternally affected shrunken-endosperm mutant seg8, NP cells did not elongate and ABA remained abundant. The amounts of the bioactive forms of gibberellins (GAs) as well as their biosynthetic precursors were strongly and transiently increased in wild-type caryopses during the transition and early storage phases. In seg8, this increase was delayed and less pronounced together with deregulated gene expression of specific ABA and GA biosynthetic genes. We concluded that differentiation of the barley NP is driven by a distinct and specific shift from lower to higher GA:ABA ratios and that the spatial-temporal change of GA:ABA balances is required to form the differentiation gradient, which is a prerequisite for ordered transfer processes through the NP. Deregulated ABA:GA balances in seg8 impair the differentiation of the NP and potentially compromise transfer of signals and assimilates, resulting in aberrant endosperm growth. These results highlight the impact of hormonal balances on the proper release of assimilates from maternal to filial organs and provide new insights into maternal effects on endosperm differentiation and growth of barley grains.
- MeSH
- Ascomycota * MeSH
- farmakologie * MeSH
- gibereliny * MeSH
- Glycine max * MeSH
- metabolismus * MeSH
- výzkum * MeSH
- Publikační typ
- časopisecké články MeSH
