Changes in free polyamine concentration induced by salt stress in seedlings of different species

Abstract

Growth rate, mineral composition and changes in polyamine concentration induced in response to salinity were studied in six crop species: spinach, lettuce, bean, pepper, beetroot and tomato. Salinity decreased growth rate, but sensitivity differed amongst the species: pepper being the most sensitive, followed by bean, tomato, lettuce and spinach, with beetroot being the most tolerant. The increase of Na + and total cation with salinity in shoots was the highest in spinach and beetroot, the most tolerant species, while in pepper it was the lowest. Changes in putrescine (Put) concentration in shoots were related to salinity tolerance (increased in the most sensitive), while changes in spermidine (Spd; decreases) and spermine (Spm; increases) were similar with most species, except for pepper in which salinity strongly increased Put, Spd and Spm. Therefore, total polyamine concentration increased in pepper shoot, while it decreased in the other species. Thus, results show that Put accumulation was a consequence of salt stress in the most sensitive species, while salt tolerant species (beetroot) showed little change in polyamine concentration, and higher concentration in both Na + and total cations. The role of polyamines or cation increased concentration after saline treatment in species with different salt tolerance is discussed.

Polyamines Interact with Hydroxyl Radicals in Activating Ca2+ and K+ Transport across the Root Epidermal Plasma Membranes

“…Yet, plants opposing this tendency (i.e. maintaining a higher Put 2+ /Spm 4+ ratio) turn out to be more salt tolerant and, importantly, to better accumulate cations, including Na + , as required for the osmotic adjustment (Zapata et al, 2008). Among other explanations, this might be related to the fact that Put 2+ could support a longer lasting potentiation of the OH dinduced passive conductance (Fig.…”

Epibrassinolide regulated synthesis of polyamines and auxins in Raphanus sativus L. seedlings under Cu metal stress

“…Putrescine (Put), Cadaverine (Cad), Spermidine (Spd) and Spermine (Spm) are major PAs involved in the regulation of a large number of physiological activities such as embryogenesis, cell division, morphogenesis, development, ethylene production and senescence (Tiburcio et al, 1997;Bagni and Tassoni, 2001;Groppa and Benavides, 2008 (Pirintsos et al, 2004;Tang et al, 2005;Shevyakova et al, 2006;Wen et al, 2008) and heavy metals (Shevyakova et al, 2006;Zapata et al, 2008;Vladimir et al, 2009). The strong antioxidant character of PAs is proven (Ha et al, 1998).…”

Changes induced by Cu2+ and Cr6+ metal stress in polyamines, auxins, abscisic acid titers and antioxidative enzymes activities of radish seedlings

“…They are now accepted as an important component of plant stress responses (Alcazar et al, 2006;Tassoni et al, 2008). Changes in the endogenous titers of polyamines have been associated with the retardation of senescence, and various environmental stresses like osmotic, salinity (Pirintsos et al, 2004;Tang et al, 2005;Shevyakova et al, 2006;Wen et al, 2008) and heavy metal stress (Shevyakova et al, 2006;Zapata et al, 2008). They have the capacity for scavenging free radicals and reactive oxygen species (Ha et al, 1998), thus exerting a strong antioxidant function during various types of stress (Groppa and Benavides, 2008).…”