Polyamines in Helianthus annuus L. during Germination under Salt Stress

Abstract

The level of the three main polyamines putrescine, spermidine, and spermine and the biosynthetic enzyme arginine decarboxylase (ADC) decreased in Helianthus annuus L. seedlings subjected to increasing (50, 100, and 150 mM) NaCl concentrations. The pattern of polyamines in control plants increased during the initial 72 h and then reached a plateau. The putrescine level showed an increase of 370% after 72 h of development. The lower salt treatment slightly diminished the overall polyamine content. The highest NaCl concentration (150 mM) induced a strong putrescine diminution (from 381 to 78.9 nmol g −1 FW) at 72 h whereas a small decrease in ADC activity was detected. ODC was detected in neither control nor treated plantlets during the experimental period. The level of spermidine also decreased, but the magnitude of the decay was less pronounced than putrescine. The fact that ODC was not detected and ADC activity followed a pattern similar to that of putrescine led us to suppose that the variation in putrescine content could be attributed entirely to the decrease in ADC activity. ␣-Difluoromethylarginine and ␣-difluoromethylornithine (ADC and ODC inhibitor, respectively) did not inhibit but delayed the onset of germination of sunflower seeds, and ␣-difluoromethylornithine increased the content of spermidine and spermine. The present data suggest that polyamines could be involved in the germination process of H. annuus seeds and in response to salt stress.

Effects of exogenous spermine on sweet sorghum during germination under salinity

“…The present study provided strong evidence that SPM improved the growth of sweet sorghum under salinity. These findings were in agreement with a previous report which found that spermine was partially responsible for restoration of growth in seedlings treated with 150 mM NaCl, and was more effective than the putrescine (Benavides et al 1997).…”

Polyamines content and physiological and biochemical responses to ladder concentration of nickel stress in Hydrocharis dubia (Bl.) Backer leaves

“…It has often been suggested that Put and derived PAs (Spd, Spm) may have distinct functions in response to stress. In several plant systems (Drolet et al 1986;Bar et al 1996;Benavides et al 1997) it has been shown that Spd and Spm act as anti-senescent compounds in response to stress, while Put produces either no effects or negative effects, such as depolarization of membranes, potassium leakage, tissue necrosis, and protein loss (Tiburcio et al 1990). So according to the present experiment, we can draw a conclusion that the decreasing of Spd and Spm, and the increasing of Put, deteriorated characters of Ni stress.…”

Putrescine catabolism via DAO contributes to proline and GABA accumulation in roots of lupine seedlings growing under salt stress

“…The accumulation of Put in the intact plants and leaves in response to the osmotic or salt stresses has been reported by many authors [2,11,12]. However, others have reported either decrease or no changes at all in the Put level or in the level of all three major PAs in response to salt stress [13][14][15].…”