Phytochrome A and B Function Antagonistically to Regulate Cold Tolerance via Abscisic Acid-Dependent Jasmonate Signaling

Abstract

Light signaling and phytohormones both influence plant growth, development, and stress responses; however, cross talk between these two signaling pathways in response to cold remains underexplored. Here, we report that far-red light (FR) and red light (R) perceived by phytochrome A (phyA) and phyB positively and negatively regulated cold tolerance, respectively, in tomato (Solanum lycopersicum), which were associated with the regulation of levels of phytohormones such as abscisic acid (ABA) and jasmonic acid (JA) and transcript levels of ABA-and JA-related genes and the C-REPEAT BINDING FACTOR (CBF) stress signaling pathway genes. A reduction in the R/FR ratio did not alter cold tolerance, ABA and JA accumulation, and transcript levels of ABA-and JA-related genes and the CBF pathway genes in phyA mutant plants; however, those were significantly increased in wild-type and phyB plants with the reduction in the R/FR ratio. Even though low R/FR treatments did not confer cold tolerance in ABA-deficient (notabilis [not]) and JA-deficient (prosystemin-mediated responses2 [spr2]) mutants, it up-regulated ABA accumulation and signaling in the spr2 mutant, with no effect on JA levels and signaling in the not mutant. Foliar application of ABA and JA further confirmed that JA functioned downstream of ABA to activate the CBF pathway in light quality-mediated cold tolerance. It is concluded that phyA and phyB function antagonistically to regulate cold tolerance that essentially involves FR light-induced activation of phyA to induce ABA signaling and, subsequently, JA signaling, leading to an activation of the CBF pathway and a cold response in tomato plants.

A Plant Phytosulfokine Peptide Initiates Auxin-Dependent Immunity through Cytosolic Ca2+ Signaling in Tomato

“…The residue was resuspended in 0.5 mL of 70% (v/v) methanol and centrifuged at 18,000g for 2 min at 4°C. The final supernatants were pipetted into glass vials and then analyzed by HPLC-MS/MS (Agilent 6460; Agilent Technologies) using the same method described previously (Wang et al, 2016).…”

Phytochrome B Negatively Affects Cold Tolerance by Regulating OsDREB1 Gene Expression through Phytochrome Interacting Factor-Like Protein OsPIL16 in Rice

“…In addition to their roles in plant photomorphogenesis, cross-talk between phytochrome-mediated light signals and cold signaling pathways has been identified in the model plant Arabidopsis and tomato (Williams et al, 1972; Kim et al, 2002; Wang et al, 2016). As early as 1972, Williams et al noticed that phytochrome could mediate short day enhancement of cold acclimation, but the molecular basis for phytochrome regulation of cold tolerance remained unknown until recent years (Williams et al, 1972).…”

“…As a result, the freezing tolerance of short-day plants was increased relative to that of LD plants in Arabidopsis (Lee and Thomashow, 2012). Wang et al (2016) found that FR and R light perceived by phyA and phyB positively and negatively regulated cold tolerance, respectively, in tomato ( Solanum lycopersicum ). FR light-induced activation of phyA triggers ABA signaling and, subsequently, JA signaling, leading to activation of the CBF pathway and a cold response in tomato plants (Wang et al, 2016).…”

Systemic induction of photosynthesis via illumination of the shoot apex is mediated by phytochrome B

“…Photoreceptors modify plant growth, development, and stress responses via alterations in phytohormone homeostasis (Jiao et al, 2007;Wang et al, 2016). Like polar auxin transport (PAT), light-induced signaling is basipetal in direction.…”