A role for spermidine in the bolting and flowering of Arabidopsis

Abstract

Several lines of experimental evidence indicate a close connection between polyamines (PAs) and reproductive development in Arabidopsis thaliana. (l) Measurement of the titers of endogenous spermidine (SPD) and putrescine (PUT), extracted from various organs of two ecotypes and a genetic line of Arabidopsis, revealed that flowers had the highest titers of both PAs, with SPD predominating. (2) In aseptic cultures of whole plants of the ecotype Columbia, the application of appropriate enzyme inhibitors lowered SPD titer while almost completely preventing bolting and flowering. When the plants were removed to an inhibitor‐free medium, bolting and flowering resumed. (3) SPD added to the medium of aseptically cultured plants of Columbia growing under short‐day (SD) conditions, where flowering is naturally delayed, increased the SPD titer and augmented the rate and extent of flowering. Under long‐day (LD) conditions, where flowering is already rapid and abundant, it did not promote flowering any further. (4) Enzyme inhibitors of SPD synthesis given shortly before the transition from SD conditions to LD conditions prevented flowering. (5) In a delayed‐flowering mutant (CS 3123), the addition of SPD significantly accelerated flowering.

Bacterial and Plant Signal Integration via D3-Type Cyclins Enhances Symptom Development in the Arabidopsis-Rhodococcus fasciansInteraction

“…In some cases, polyamines are believed to be easily biochemically interconverted; therefore, Put, Spd, and Spm would be physiologically equivalent (Applewhite et al, 2000;Mattoo et al, 2010). In other cases, Put clearly has opposite and contrasting functions when compared with Spd and Spm Mattoo et al, 2010).…”

Involvement of Polyamine in Floral and Fruit Development

“…Secondly, utilization of polyamine biosynthetic enzyme inhibitors prevented flowering, which was resumed when the inhibitors were absent or when polyamines were added exogenously. Much work has been carried out using inhibitors in order to probe the relationship between polyamines and floral development 2,3,20,34,77,82 . For instance, methylglyoxal bis(guanylhydrazone) (MGBG), an inhibitor of SAMDC, caused strong inhibition of flowering in Spirodela punctata, whereas the inhibitory effect was abolished by applying Spd exogenously 20 .…”

Relationship between Endogenous Polyamines and Floral Bud Differentiation in Chrysanthemum morifolium under Short-day Conditions

“…Some authors suggest that PAs could be components of floral stimulus (Caffaro et al, 1994;Havelange et al, 1996), while others maintain that PAs influence transport of a floral stimulus (Applewhite et al, 2000). In this study, the rapid increase in the free-Put pool in apical buds during stage 2 illustrated its importance to initiation of floral bud formation.…”

“…The importance of polyamines in flower bud differentiation has been confirmed by numerous laboratory studies (Aribaud and Martin-Tanguy, 1994;Huang et al, 2004;Meijón et al, 2011;Wimalasekera et al, 2011). Endogenous PA concentrations in plants change dramatically during the transition from vegetative phase to reproductive (Applewhite et al, 2000;Aribaud and Martin-Tanguy, 1994;Davis, 2009;Meijón et al, 2011;Wimalasekera et al, 2011). Conjugated PAs have been shown to play a key role in floral development (Martin-Tanguy, 1997) and be of particular significance for regulation of PA concentration (Bagni and Tassoni, 2001).…”