Polyamines - a new metabolic switch: Crosstalk with networks involving senescence, crop improvement, and mammalian cancer therapy

Authors: SOBIESZCZUK-NOWICKA, EWA - Adam Mickiewicz University; PALUCH-LUBAWA, EWELINA - Adam Mickiewicz University; Mattoo, Autar; JELONEK, MAGDALENA - Adam Mickiewicz University; GREGERSEN, PER - Aarhus University; PACAK, ANDRZEJ - Adam Mickiewicz University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2019
Publication Date: 7/3/2019
Citation: Sobieszczuk-Nowicka, E., Paluch-Lubawa, E., Mattoo, A.K., Jelonek, M.A., Gregersen, P.L., Pacak, A. 2019. Polyamines - a new metabolic switch: Crosstalk with networks involving senescence, crop improvement, and mammalian cancer therapy. Frontiers in Plant Science. 10:1-12. https://doi.org/10.3389/fpls.2019.00859.
DOI: https://doi.org/10.3389/fpls.2019.00859

Interpretive Summary: All types of stresses limit plant growth and crop productivity. Achieving global food security whilst reconciling with the changing environment is a major challenge faced today by mankind. Thus, it is critical to increase plant productivity, improve food quality and enhance agricultural sustainability of crops. In this regard, our research on the anabolism/catabolism of ubiquitous growth hormone, the biogenic amine polyamine (PA), has shown that PAs play a role in reprogramming metabolic switches such that plant leaf senescence can be altered and reversed for a particular pro-growth phenotype or where organ death is enhanced without affecting the energy-use efficiency of plants. Also, exogenous application of natural and synthetic PAs can help plants to improve their tolerance against a broad spectrum of stress factors which, in turn, can lead to higher plant productivity as well as extend the boundaries of crop cultivation. Our research in the polyamine science arena has made inroads into PA omic profiling, developing novel germplasm by genetic engineering, and unraveling the interactions between polyamines, other hormones and stress- responsive molecules such as nitic oxide (NO). Such studies should bring new insights to our understanding of PA-related stress induced-senescence and cell death mechanism(s). This manuscript highlights and updates recent advances in these areas. Its contents will be of interest to biologists, nutritionists, academicians, industry, mammalian biologists and scientists.

Technical Abstract: Polyamines (PAs) are low molecular weight organic cations comprising biogenic amines that play multiple roles in plant growth and senescence. Our model plant for studying PA regulation in plants is barley. We have previously demonstrated that PA metabolism plays a central role in metabolic and genetic reprogramming during dark-induced leaf senescence (DILS). Also, there is evidence that robust PA catabolism can influence the rate of senescence progression in plants. Therefore, we opine that it is important to decipher senescence-dependent polyamine-based multidirectional metabolic crosstalks to determine mechanisms of PA-mediated regulation and involvement in plant death, particularly in relation to the re-mobilization of nutrients during senescence. The need is for optimizing application of PA biosynthesis inhibitors, developing transgenic approaches to over-express or silence the rate-limiting PA biosynthetic and catabolic genes, and developing barley germplasm having pro- and anti-senescence traits. Thus, PA-mediated delay in the onset of senescence would extend the photosynthesizing capacity and increase grain starch content in malting grains. On the other hand, accelerating the onset of senescence can increase nitrogen content in grains for animal feed. Unravelling the ‘polyamine metabolic switch’ in senescence biology would provide an element of novelty in understanding the mechanisms of cell regulation both in plants and other model systems. Delineation of the roles of PAs in induced-senescence and senescence-related autophagy mechanisms should further our knowledge about senescence and autophagy at cellular and molecular levels not only in plant systems but also in mammalian systems. For instance, a number of studies have utilized the inhibitors of PA biosynthesis to block cell viability in animal model systems (cell tumor lines) to control some cancers by leading proliferative cancer cells towards cell death. Also, polyamine conjugates have been used as signal carriers for slow release of regulatory molecules, such as nitric oxide (NO), in the targeted cells. Such an outcome could lead to the development of novel therapeutics for human health wellness and plant resistance/tolerance to stress stimuli.