Leaf Blackening

Hoffman, E. W.; Vardien, Waafeka; Jacobs, G.; Windell, Nicole E.

doi:10.1002/9781119431077.ch3

Cited by 4 publications

(1 citation statement)

References 52 publications

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“…Tannins are usually water-insoluble and can be found as precipitate complexes [91]. Therefore, leaf blackening is usually minimized by using chemicals such as lead acetate and phenyl mercuric acetate, which have been used to precipitate these phenolic compounds from a vase solution [92]. Apart from these processes, microbial growth promoted by the leaching of these compounds also results in vascular blockage [90].…”

Section: Tanninsmentioning

confidence: 99%

Postharvest Chemical Treatment of Physiologically Induced Stem End Blockage Improves Vase Life and Water Relation of Cut Flowers

Manzoor,

Bashir,

Naveed

et al. 2024

Horticulturae

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Wound-induced xylem occlusion significantly affects the vase life of cut flowers, as oxidative stress and the polymerization of phenolic compounds lead to the deposition of phenolic compounds/secondary metabolites in the stem ends of cut flowers to heal open tissues of freshly cut stems and prevent microbial invasion. However, this deposition causes blockage of vessels, reduced water uptake, and shortened vase life. The physiological plugging of vessels is linked with various oxidative enzymes’ (PAL, PPOs, LACs, and COs) actions taken to increase the synthesis of different compounds, e.g., lignin, suberin, tyloses, gel, and latex, in wounded areas. The use of chemical preservatives/enzyme inhibitors is one of the safest and most efficient techniques employed to minimize vascular blockage and inhibit phenolic compounds deposition and exudation. This review mainly discusses the types of oxidative enzymes, their pathways and biochemistry along with production of secondary metabolites, their biosynthesis, and their modes of action involved in vascular blockage. It also summarizes the different types of preservatives used in postharvest treatments to improve relative water uptake, flower fresh weight, petal protein content, and hydraulic conductance and prolong the vase life of cut flowers during storage. It is hoped that this elaborate study will help researchers in designing new studies concerning occlusion caused by the accumulation of phenolic compounds in vessels.

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Section: Tanninsmentioning

confidence: 99%

Postharvest Chemical Treatment of Physiologically Induced Stem End Blockage Improves Vase Life and Water Relation of Cut Flowers

Manzoor,

Bashir,

Naveed

et al. 2024

Horticulturae

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Application of Metabolomics Tools to Determine Possible Biomarker Metabolites Linked to Leaf Blackening in Protea

Masike

Villiers

Hoffman

et al. 2020

J. Agric. Food Chem.

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The postharvesting disorder leaf blackening is the main cause of product rejection in Protea during export. In this study, we report an investigation into metabolites associated with leaf blackening in Protea species. Methanol extracts of leaf and involucral bract tissue were analyzed by liquid chromatography hyphenated to photodiode array and high-resolution mass spectrometry (LC−PDA−HRMS), where 116 features were annotated. Analytical data obtained from 37 Protea species, selections, and hybrids were investigated using metabolomics tools, which showed that stems susceptible to leaf blackening cluster together and contained features identified as benzenetriol-and/or hydroquinone-derived metabolites. On the other hand, species, selections, and cultivars not prone to blackening were linked to metabolites with known protective properties against biotic and abiotic stressors. During the browning process, susceptible cultivars also produce these protective metabolites, yet at innately low levels, which may render these species and cultivars more vulnerable to blackening. Metabolites that were found to be correlated to the instigation of the browning process, all comprising benzenetriol-and hydroquinone-glycoside derivatives, are highlighted to provide preliminary insights to guide the development of new Protea cultivars not susceptible to leaf blackening.

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Detailed Phenolic Characterization of Protea Pure and Hybrid Cultivars by Liquid Chromatography–Ion Mobility–High Resolution Mass Spectrometry (LC-IM-HR-MS)

Masike

Villiers

Hoffman

et al. 2019

J. Agric. Food Chem.

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In this study we report a detailed investigation of the polyphenol composition of Protea pure (P. cynaroides and P. neriifolia) and hybrid cultivars (Black beauty and Limelight). Aqueous methanol extracts of leaf and bract tissues were analyzed by ultrahigh pressure liquid chromatography hyphenated to photodiode array and ion mobility-high resolution mass spectrometric (UHPLC-PDA-IM-HR-MS) detection. A total of 67 metabolites were characterized based on their relative reversed phase (RP) retention, UV−vis spectra, low and high collision energy HR-MS data, and collisional cross section (CCS) values. These metabolites included 41 phenolic acid esters and 25 flavonoid derivatives, including 5 anthocyanins. In addition, an undescribed hydroxycinnamic acid-polygalatol ester, caffeoyl-O-polygalatol (1,5-anhydro-[6-O-caffeoyl]-sorbitol(glucitol)) was isolated and characterized by 1D and 2D NMR for the first time. This compound and its isomer are shown to be potential chemo-taxonomic markers.

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Leaf Blackening

Cited by 4 publications

References 52 publications

Postharvest Chemical Treatment of Physiologically Induced Stem End Blockage Improves Vase Life and Water Relation of Cut Flowers

Postharvest Chemical Treatment of Physiologically Induced Stem End Blockage Improves Vase Life and Water Relation of Cut Flowers

Application of Metabolomics Tools to Determine Possible Biomarker Metabolites Linked to Leaf Blackening in Protea

Detailed Phenolic Characterization of Protea Pure and Hybrid Cultivars by Liquid Chromatography–Ion Mobility–High Resolution Mass Spectrometry (LC-IM-HR-MS)

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