Nitric Oxide Represses the Arabidopsis Floral Transition

Abstract

The correct timing of flowering is essential for plants to maximize reproductive success and is controlled by environmental and endogenous signals. We report that nitric oxide (NO) repressed the floral transition in Arabidopsis thaliana. Plants treated with NO, as well as a mutant overproducing NO (nox1), flowered late, whereas a mutant producing less NO (nos1) flowered early. NO suppressed CONSTANS and GIGANTEA gene expression and enhanced FLOWERING LOCUS C expression, which indicated that NO regulates the photoperiod and autonomous pathways. Because NO is induced by environmental stimuli and constitutively produced, it may integrate both external and internal cues into the floral decision.

Nitrogen dioxide is a positive regulator of plant growth

“…Exogenous NO delays flowering of Arabidopsis Col-0, 8 whereas exogenous NO 2 significantly accelerates the flowering time of Arabidopsis Col-0 and C24, which are early and late flowering accessions, by ~6 and 2 d, respectively. 2 There are also reports of similar accelerations in flowering time, and increases in flower number and fruit yield when tomatoes are treated with NO 2 .…”

“…that treatment of Arabidopsis seedlings with the NO donor sodium nitroprusside enhances vegetative growth 8 and that exposure to NO gas promotes expansion of pea leaf discs 9 and vegetative growth of spinach. 10 Thus, NO and NO 2 likely stimulate vegetative growth through similar mechanisms.…”

Nitrogen regulates CRY1 phosphorylation and circadian clock input pathways

“…NO is involved in photoperiod and autonomous flowering pathway (NO represses the amplitudes of output pathway components CO and GI). 5 These correlations imply that N-regulated flowering pathways may be very complex. We should consider more about carbon metabolite signals and NO signals in the future studies.…”

“…4 Similar to the high N condition, nitric oxide (NO) also causes the inhibition of floral transition through repressing circadian-clock output genes CO and GIGANTEA (GI). 5 In summary, N, C and NO may influence the circadian clock through the input pathway, the central oscillator pathway and the output pathway, respectively (Fig. 1).…”

Positive effects of nitric oxide onSolanum lycopersicum

“…Nitric oxide (NO) is a signaling molecule (Duner et al 1999), which participates in different physiological processes of plant (He et al 2004;Delledonne 2005;De Pinto et al 2006). Plants produce NO via the oxidation of arginine to citrulline (Neill et al 2003a).…”