Role of other plant organs in gibberellic acid-induced delay of leaf senescence in alstroemeria cut flowers

Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in senescing plants and propose a critical role of its NH2-terminal chloroplast transit peptide. The 13-LOX enzyme identified here accumulated in the plastid envelope and catalyzed the dioxygenation of unsaturated membrane fatty acids, leading to a selective destruction of the chloroplast and the release of stromal constituents. Because 13-LOX pathway products comprise compounds involved in insect deterrence and pathogen defense (volatile aldehydes and oxylipins), a mechanism of unmolested nitrogen and carbon relocation is suggested that occurs from leaves to seeds and roots during fall.

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The Possible Protective Role of N-acetylcysteine Against Gibberellic Acid-Induced Lung Structural Changes of the Adult Albino Rat

Egyptian Journal of Histology ◽

10.21608/ejh.2022.102176.1578 ◽

2022 ◽

Vol 0 (0) ◽

pp. 0-0

Author(s):

Reneah Bushra ◽

Merry Shenouda

Keyword(s):

Gibberellic Acid ◽

Structural Changes ◽

Protective Role ◽

Albino Rat

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Role of Histones During Leaf Senescence

Senescence Signalling and Control in Plants ◽

10.1016/b978-0-12-813187-9.00011-1 ◽

2019 ◽

pp. 187-197 ◽

Cited By ~ 1

Author(s):

Bhubaneswar Pradhan ◽

Krishna Kumar Jangid ◽

Maryam Sarwat ◽

Sujit Kumar Bishi

Keyword(s):

Leaf Senescence

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The role of gibberellic acid in the hydrolysis of endosperm reserves in Zea mays

Planta ◽

10.1007/bf00384007 ◽

1974 ◽

Vol 121 (1) ◽

pp. 67-74 ◽

Cited By ~ 14

Author(s):

B. M. R. Harvey ◽

Ann Oaks

Keyword(s):

Zea Mays ◽

Gibberellic Acid ◽

Hydrolysis Of

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Induction of Changes in Internal Gas Pressure of Bulky Plant Organs by Temperature Gradients

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.2.308 ◽

1990 ◽

Vol 115 (2) ◽

pp. 308-312 ◽

Cited By ~ 8

Author(s):

Kenneth A. Corey ◽

Zhi-Yi Tan

Keyword(s):

Bath Temperature ◽

Ideal Gas ◽

Gas Pressure ◽

Temperature Gradients ◽

Maximum Pressure ◽

Plant Organs ◽

Ideal Gas Law ◽

Increasing Temperature ◽

Pressure Changes

Water manometers were connected to fruits of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and then fruits were submerged in water baths providing initial temperature gradients between fruit and water of 0 to 19C. Apple (Malus domestics Borkh.) fruits, carrot (Daucus carota L.) roots, witloof chicory (Cichorium intybus L.) roots, rhubarb Rheum rhabarbarum L.) petioles, and pokeweed (Phytolacca americana L.) stems were subjected to water bath temperature gradients of 5C. Internal partial vacuums developed in all organs within minutes of imposing the gradients. The maximum partial vacuums in tomato and pepper fruits increased with increasing temperature gradients. Uptake of water accompanied changes in internal pressure reaching maxima of 17% (w/w) and 2% (w/w) of pepper and tomato fruits, respectively, after 22 hours. Maximum pressure changes achieved in bulky organs deviated from those predicted by the ideal gas law, possibly due to concomitant changes in gas pressure upon replacement of intercellular spaces with water and dissolution of CO2. Partial vacuums also developed in pepper fruits, rhubarb petioles, and pokeweed stems following exposure to air 15C cooler than initial organ temperatures. Results point to the role of temperature gradients in the transport of liquids and gases in plant organs.

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Role of spermidine in the stabilization of the apoprotein of the light-harvesting chlorophyll a/b-protein complex of photosystem II during leaf senescence process

Acta Physiologiae Plantarum ◽

10.1007/s11738-999-0066-0 ◽

1999 ◽

Vol 21 (2) ◽

pp. 127-132 ◽

Cited By ~ 34

Author(s):

Jolanta Legocka ◽

Irena Zajchert

Keyword(s):

Photosystem Ii ◽

Chlorophyll A ◽

Leaf Senescence ◽

Protein Complex ◽

Light Harvesting

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Characters and origin of vessels with heterogenous structure in leaf and flower abscission zones

Canadian Journal of Botany ◽

10.1139/b98-213 ◽

1999 ◽

Vol 77 (2) ◽

pp. 253-261 ◽

Cited By ~ 5

Author(s):

JP André ◽

A M Catesson ◽

M Liberman

Keyword(s):

Cell Differentiation ◽

Lycopersicon Esculentum ◽

Secondary Xylem ◽

Abscission Zone ◽

Leaf Abscission ◽

Cell Maturation ◽

Casting Method ◽

Plant Organs ◽

Flower Abscission

The lifetime of many plant organs does not exceed a few weeks or a few months. These organs separate from the plant at the level of specialized abscission zones. The observation of xylem vasculature in abscission zones, a largely neglected subject, revealed original features when a vessel casting method was used. In all species of dicotyledons examined so far, flower and leaf abscission zones possessed heterogenous metaxylem vessels adjoining protoxylem and secondary xylem vessels with homogenous patterns of lignified thickenings. Heterogenous metaxylem vessel thickenings were helical, reticulate, or scalariform elements when in the abscission zone and pitted elements on the proximal and the distal sides. The origin and possible role of these vessels are considered. Data obtained on the flower abscission zone of tomato (Lycopersicon esculentum Mill.) suggest that formation of heterogenous vessels results from localized changes in the rhythm of cell differentiation and cell maturation inside the procambium-cambium continuum.Key words: abscission zone, cambium, differentiation, heterogenous vessels, procambium, vessel cast.

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