Salicylic acid regulates flowering time and links defence responses and reproductive development

Abstract

SummaryFlowering relies on signaling networks that integrate endogenous and external cues. Normally, plants ower at a particular season, re¯ecting day length and/or temperature cues. However, plants can surpass this seasonal regulation and show precocious¯owering under stress environmental conditions. Here, we show that UV-C light stress activates the transition to¯owering in Arabidopsis thaliana through salicylic acid (SA). Moreover, SA also regulates¯owering time in non-stressed plants, as SA-de®cient plants are latē owering. The regulation of¯owering time by SA seems to involve the photoperiod and autonomous pathways, but it does not require the function of the¯owering time genes CONSTANS (CO), FCA, or FLOWERING LOCUS C (FLC ).

PROHIBITIN3 Forms Complexes with ISOCHORISMATE SYNTHASE1 to Regulate Stress-Induced Salicylic Acid Biosynthesis in Arabidopsis

“…ICS1 transcript and SA levels are induced by UV-C stress in Arabidopsis (Garcion 169 et al, 2008;Martínez et al, 2004;Nawrath et al, 2002;Serrano et al, 2013;Shapiro and 170 …”

“…Its developmental roles include 81 the regulation of flowering time (Martínez et al, 2004), leaf longevity (slow cell death; 82 Morris et al, 2000;Zhang et al, 2013), and biomass (Abreu et al, 2009) …”

Peroxisomal Hydrogen Peroxide Is Coupled to Biotic Defense Responses by ISOCHORISMATE SYNTHASE1 in a Daylength-Related Manner

“…Consistent with this explanation, it has recently been reported that longer daylengths increase leaf injury induced by equal-time ozone exposures (Vollsnes et al, 2009). Because there is evidence for overlap between SA, pathogen responses, and the regulation of flowering (Martínez et al, 2004), the requirement for LD-dependent SA accumulation in cat2 may reflect the coordination of H 2 O 2 -triggered lesions with the flowering program. Some aspects of pathogen responses interact with or are influenced by the phytochrome pathway (Genoud et al, 2002;Griebel and Zeier, 2008), while cryptochrome has been implicated in singlet oxygen-mediated effects (Danon et al, 2006).…”

Salicylate Accumulation Inhibits Growth at Chilling Temperature in Arabidopsis

“…SA also seems to be involved in responses to abiotic stresses, such as ozone (Sharma et al, 1996;Rao and Davis, 1999;Koch et al, 2000), salt and osmotic stress (Borsani et al, 2001;Molina et al, 2002;Shim et al, 2003), UV-B (Surplus et al, 1998), drought (Senaratna et al, 2000;Nemeth et al, 2002), paraquat , and heat (Dat et al, 1998a(Dat et al, , 1998b(Dat et al, , 2000Lopez-Delgado et al, 1998a;Senaratna et al, 2000;Larkindale and Knight, 2002;Clarke et al, 2004). Stress-influenced developmental transitions, including flowering (Hatayama and Takeno, 2003;Martinez et al, 2004), tuberization (Lopez-Delgado and Scott, 1997), and senescence (Morris et al, 2000), may also involve SA.…”