Integrated Signaling in Flower Senescence An Overview

• Published in: Plant signaling & behavior Vol. 2; no. 6; pp. 437 - 445
• Main Authors: Tripathi, Siddharth Kaushal, Tuteja, Narendra
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.11.2007; Landes Bioscience
• Subjects: abiotic stress; abscisic acid; Binding; Biology; Bioscience; Calcium; Cancer; Cell; cell membranes; corolla; Cycle; DNA; drought; ethylene; Landes; membrane permeability; nucleases; organelles; Organogenesis; pollination; proteinases; Proteins; Review; RNA; wilting; senescence; flowers; environmental factors; pollination; plant hormones; programmed cell death; ethylene; petals; senescence-associated genes
• ISSN: 1559-2316; 1559-2324; 1559-2324
• DOI: 10.4161/psb.2.6.4991

Flower senescence is the terminal phase of developmental processes that lead to the death of flower, which include, flower wilting, shedding of flower parts and fading of blossoms. Since it is a rapid process as compared to the senescence of other parts of the plant therefore it provides excellent model system for the study of senescence. During flower senescence, developmental and environmental stimuli enhance the up-regulation of catabolic processes causing breakdown and remobilization of cellular constituents. Ethylene is well known to play regulatory role in ethylene-sensitive flowers while in ethylene-insensitive flowers abscisic acid (ABA) is thought to be primary regulator. Subsequent to perception of flower senescence signal, death of petals is accompanied by the loss of membrane permeability, increase in oxidative and decreased level of protective enzymes. The last stages of senescence involve the loss of of nucleic acids (DNA and RNA), proteins, and organelles, which is achieved by activation of several nucleases, proteases and wall modifiers. Environmental stimuli such as pollination, drought and other stresses also affect senescence by hormonal imbalance. In this article we have covered the followings: perception mechanism and specificity of flower senescence, flower senescence-associated events, like degradation of cell membranes, proteins and nucleic acids, environmental/external factors affecting senescence, like pollination and abiotic stress, hormonal and non-hormonal regulation of flower/petal senescence, and finally the senescence associated genes (SAGs) have also been described.