The role of phytochrome B, D and E in thermoperiodic responses of Arabidopsis thaliana

Abstract

The objective of this work was to study the role of the phytochromes (phy) B, D and E in the thermoperiodic control of elongation and flowering time in Arabidopsis thaliana. WT, and phyB, phyD and phyE single mutants, and phyB phyD and phyB phyE double mutants, were grown under day/night temperatures (DT/NT) of 12/22°C, 17/17°C or 22/12°C (negative, zero and positive DIF, respectively) for inflorescence stem length measurements, and under DT/NT 17/25°C or 25/17°C (negative and positive DIF, respectively) for leaf morphology and flowering time measurements. In WT final length of the stem, petiole and leaf blade were longer under positive DIF compared to negative DIF. The temperature effect was stronger in the leaf petiole than the stem, whereas only a slight change was seen in the leaf blade length direction and none in the width direction. The temperature effect on stem and petiole elongation was reduced or nearly eliminated in the genotypes lacking phyB, while a phyD or a phyE mutation had no influence or a slightly positive influence on the temperature effect, respectively. These results suggest that phyB, and not phyD or phyE, is needed for a complete thermoperiodic control of elongation growth in A. thaliana. For all genotypes tested, plants flowered earlier at negative DIF than positive DIF, suggesting that none of the three phytochromes B, D, or E is needed for a thermoperiodic control of flowering time in A. thaliana.

Antiphase Light and Temperature Cycles Affect PHYTOCHROME B-Controlled Ethylene Sensitivity and Biosynthesis, Limiting Leaf Movement and Growth of Arabidopsis

“…In agreement with the work of Thingnaes et al (2008), elongation of phyB9 mutant leaves was not reduced by our 2DIF treatment (Supplemental Fig. S5A).…”

“…It has been reported that the Arabidopsis photoreceptor PHYB mutant phyB1 is insensitive to growth inhibition under 2DIF; however, the underlying mechanism for this insensitivity remained unclear (Thingnaes et al, 2008). In agreement with the work of Thingnaes et al (2008), elongation of phyB9 mutant leaves was not reduced by our 2DIF treatment (Supplemental Fig.…”

“…On the other hand, the 2DIF growth response in Arabidopsis was associated with reduced auxin levels (Thingnaes et al, 2003). The photoreceptor PHYTOCHROME B (PHYB) has been shown to be important for the response to 2DIF, as phyB mutants of Arabidopsis (Thingnaes et al, 2008) and cucumber (Cucumis sativus; Patil et al, 2003) are insensitive to 2DIF.…”

Thermoperiodic Control of Hypocotyl Elongation Depends on Auxin-Induced Ethylene Signaling That Controls Downstream PHYTOCHROME INTERACTING FACTOR3 Activity

“…The loss of PHYB function results in increased hypocotyl elongation, which is insensitive to 2DIF (Thingnaes et al, 2008;Bours et al, 2013). PIF protein stability is highly dependent on PHYB-mediated degradation (Monte et al, 2007), and a phyB mutant is, therefore, expected to have increased levels of PIF protein.…”

Effects of diurnal temperature range and seasonal temperature pattern on the agronomic traits of fibre flax (Linum usitatissimum L.)

“…Compared with oilseed flax cultivars, fibre flax plants are typically taller, with less branching and lower seed production (Booth et al 2004). Fibre flax is not only valued for its bast fibres, used in textiles such as linen, but nowadays it has become an important, versatile and expanding crop with numerous novel uses including insulation materials, paper, particle board and car interior panels (Dimmock et al 2005;Venglat et al 2011).…”