Ultrastrucrure and Histochemistry of Traumatic Gum Ducrs in the Wood of Azadiracht A Indica A. Juss.

Nair, Mahesh N.; Shah, J. J.; Subramanyam, S. V.

doi:10.1163/22941932-90000403

Cited by 11 publications

(14 citation statements)

References 18 publications

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“…For example, it is quite common to find the terms gum veins or ducts and gum used indiscriminately to refer to kino veins and kino (e.g. Greenwood and Morey 1979;Nair et al 1983;Rajput et al 2005;Setia 1984a, b). Usually, the description of the anatomy and physiology of internal secretory structures does not involve the chemical composition of the exudates.…”

Section: What Are Kino Veins?mentioning

confidence: 99%

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Holocrine secretion and kino flow in angiosperms: their role and physiological advantages in plant defence mechanisms

Cabrita¹

2020

Trees

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Key message Flow within internal secretory systems derived from autolyzing epithelia in kino-producing angiosperms may have lower metabolic energy costs. This presents physiological advantages and possibly constitutes an evolutionary step of these species compared to resin flow in conifers in using internal secretory systems in plant defence mechanisms. Abstract Kino is a plant exudate, rich in polyphenols, produced by several angiosperms in reaction to injury of the cambium. It flows out of kino veins, which compose an anatomically distinct continuous system of tangentially anastomosing canals produced by the cambium upon damage, encircling plant stems and branches. Kino is loaded into the vein lumen by autolysis of a cambiform epithelium lined by suberized cells that separate kino veins from the surrounding axial parenchyma. A model describing kino flow is presented to investigate how vein distribution and structure, as well as the loading, solidification, and viscosity of kino affect flow. Considering vein anatomy, viscosity, and a time-dependent loading of kino, the unsteady Stokes equation was applied. Qualitatively, kino flow is similar to resin flow observed on conifers. There is an increase in flow towards the vein open end, with both pressure and flow depending on the vein dimensions, properties, and loading of kino. However, kino veins present a much smaller specific resistance to flow compared to resin ducts. Also, unlike resin loading in conifers, the loading of kino is not pressure-driven. The pressure and pressure gradient required to drive an equally fast flow are smaller than what is observed on the resin ducts of conifers. These results agree with previous observations on some angiosperms and suggest that flow within internal secretory systems derived from autolysing epithelia may have lower metabolic energy costs; thus presenting physiological advantages and possibly constituting an evolutionary step of angiosperms in using internal secretory systems in plant defence mechanisms compared to resin flow in conifers. Understanding of how these physiological and morphological parameters affect kino flow might be useful for selecting species and developing more sustainable and economically viable methods of tapping gum and gum resin in angiosperms.

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Section: What Are Kino Veins?mentioning

confidence: 99%

“…Acacia nilotica (L.) Delile (Subrahmanyam 1981), Azadirachta indica A.Juss. (Rajput et al 2005;Nair et al 1983), Bombax ceiba L. (Babu and Shah 1987), Eucalyptus nitens (H. Deane & Maiden) Maiden (Eyles andMohammed 2002, 2003), Kydia calycina Roxb. (Venkaiah 1982), Moringa oleifera Lam.…”

Section: The Development Of Kino Veinsmentioning

confidence: 99%

Holocrine secretion and kino flow in angiosperms: their role and physiological advantages in plant defence mechanisms

Cabrita¹

2020

Trees

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“…Some of the dictyosomal vesicles have a granular core o r fibrillar material, resembling the material of the inner tangential wall. Dictyosomes are reported to produce both acid and neutral polysaccharides in mucilage ducts (BOUCHET & DEYSSON 1974) and in traumatic gum ducts (NAIR et al 1983). In general, my observations agrce with this view, it appears that the dictyosome-derived vesicles are involved in gum production, according to my morphological observations.…”

Section: Discussionmentioning

confidence: 99%

“…Such occurrence of lysis of epithelial cells at the end of secretion in a schizogenously and lysigenously differentiated duct is common. Darkening of cells is reported in the epithelial cells of resin ducts in the primary phloem of Mang$era indicn (JOEL & FAHN 1980) and in Anacardium occidenrale (NAIR et al 1983); and in secretory hairs of Inula viscosa (WERKER & FAHN 1981).…”

Section: Discussionmentioning

confidence: 99%

Ultrastructure of gum‐resin ducts in Ailanthus excelsaROXB

Venkaiah

1990

Feddes Repertorium

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In Ailanthus excelsa ROXB., the gum‐resin duct in the pith of the stem develop schizogenously. It is suggested that dictyosomes are involved in dissolution of the middle lamella of radial walls of epithelial cells by secretion of lytic enzymes into the cell walls. In epithelial cells of young ducts osmiophilic droplets are observed in plastids and mitochondria. Epithelial cells resemble transfer cells in having few wall ingrowths. The cytoplasm of the epithelial cells of active ducts is rich in rough and smooth ER, free ribosomes, polysomes, mitochondria with swollen cristae, plastids with osmiophilic droplets, dictyosomes and vesicles. Upto and through active duct a dense, osmiophilic material is synthesized in plastids and mitochondria, and then appears to be transported through the plasmalemma by granulocrine secretion. Dictyosome‐derived vesicles appear to be involved in the secretion of gum polysaccharides. Epithelial cell walls facing the duct lumen are loose appearance and sloughed off wall material. After the secretory phase, the cytoplasm of the epithelial cell disintegrates.

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“…Some of the samples were fixed in FAA (formalin : glacial acetic acid : 50% ethanol, 1 : 1 : 8), and sections were cut on a sliding microtome and stained in toluidine blue 0 (O 'Brien, Feder & McCully, 1964) for histological observations. Sections, 0.5-1.0 pm thick, of different regions of the wood were cut with a Dupont JB4 microtome using glass knives after processing and embedding the material in Spurr (Nair, Shah & Subramanyam, 1983).…”

Section: Methodsmentioning

confidence: 99%

Wood anatomy and heartwood formation in Neem (Azadirachta indica A. Juss.)

Nair¹

1988

Botanical Journal of the Linnean Society

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The wood of Azadirachta indica is diffuse porous. Axial parenchyma is paratracheal banded or vasicentric. Rays are uniseriate to multiseriate and heterocellular with procumbent and upright cells. There is a strong negative correlation between vessel member length and diameter. The vulnerability and mesomorphic values are different in two trees of almost the same age growing in the same locality. The vessel member wall has spiral thickenings on its inner surface. Axial and ray parenchyma cells and sometimes vessels and fibres of the heartwood show the presence of extractives. The necrobiosis of the parenchyma cells occurs at the heartwood boundary. Senescence and death of parenchyma cells are associated with depletion of starch grains and accumulation of extractives. There is a climacteric rise in succinate dehydrogenase and acid phosphatase activities at the sapwood‐heartwood interface which may be associated with heartwood formation. Peroxidase activity is greater near the cambial zone, indicating its probable role in lignification.

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Ultrastrucrure and Histochemistry of Traumatic Gum Ducrs in the Wood of Azadiracht A Indica A. Juss.

Cited by 11 publications

References 18 publications

Holocrine secretion and kino flow in angiosperms: their role and physiological advantages in plant defence mechanisms

Holocrine secretion and kino flow in angiosperms: their role and physiological advantages in plant defence mechanisms

Ultrastructure of gum‐resin ducts in Ailanthus excelsaROXB

Wood anatomy and heartwood formation in Neem (Azadirachta indica A. Juss.)

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