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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #350472
Title: Polyamine as signaling molecules and leaf senescence

Author
item Mattoo, Autar
item SOBIESZCZUK-NOWICKA, EWA - Adam Mickiewicz University

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 2/15/2018
Publication Date: 12/10/2018
Citation: Mattoo, A.K., Sobieszczuk-Nowicka, E. 2018. Polyamine as signaling molecules and leaf senescence. In: Sarwat, M., Tuteja, N., editors. Senescence Signalling and Control in Plants. New York, NY: Elsevier. p. 125-138.

Interpretive Summary: Leaf senescence that causes leaf color changes during autumn and occurs prior to the excision of the leaves from the parent plant, involves complex transcriptional and hormonal regulatory networks. It is important to study because much of the senescence-mediated metabolites are exported to younger leaves and in some cases for seed development. Some of the molecular and physiological processes involved in this process have been revealed using cytological and biotechnological techniques. In addition to the elucidation of phenomenology, various transcription factors have been identified as regulatory genes controlling senescence but crosstalk among them and their downstream factors is still in infancy and needs to be fully explored. This invited book chapter provides a review of recent progress made in understanding leaf senescence induced by long duration of darkness of plants, involvement of biogenic amine oxidation in this process, and a perspective on a possible nexus between nitrous oxide, polyamines and hydrogen peroxide as a signaling triad that may regulate leaf senescence. This information will be useful to agricultural scientists and plant technologists.

Technical Abstract: Leaf senescence is a regulated developmental program, an endogenous process which is also induced by changes in the environmental factors including darkness, nutrient deficiency, pathogens or abiotic stresses. Research into biochemical and molecular processes involved in the senescence phenomenon has revealed interesting phenomenology and added to our understanding of this cellular phenomenon. Leaf senescence is divided generally into three phases: initiation, cellular degradation, and final termination that leads to cell death and leaf fall. Hormones ethylene, abscisic acid (ABA), brassinosteroids, salicylic acid and jasmonates (MeJa), are considered as promoters while cytokinins and gibberellins as inhibitors of leaf senescence. One of the recently recognized regulators of leaf senescence is a group of the biogenic amines, called polyamines (PAs). PAs constitute diamine putrescine, triamine spermidine, and tetra-amine spermine/thermo-spermine. Since the latter are found in all compartments of a plant cell, they may participate in regulating a specific, or series of, function(s) in any cellular compartment. Recent identification of thermo-spermine (T-Spm), first discovered in thermophilic bacteria, as a stress regulator has attracted attention. In this review we provide a window into the role of PAs in induced-senescence phenomenon, with special reference to barley. We discuss subject matter related to the sensing of cellular fluctuations in PA concentrations; cross-talk between PAs and plant hormones in terms of signaling; nexus between PA catabolism, H2O2, GABA and senescence; PA oxidation-derived H2O2 as a signal generated in the chloroplasts; and finally a perspective on a possible nexus between nitrous oxide (NO), PA and H2O2 as a signaling triad that may regulate leaf senescence.