Day and Night Temperature Responses in Arabidopsis: Effects on Gibberellin and Auxin Content, Cell Size, Morphology and Flowering Time

Abstract

The effect of 16 different day (DT) and night (NT) temperature combinations (DT and NT 12, 17, 22 and 27 degrees C) on rosette leaf growth, flower stem elongation and flowering time in Arabidopsis thaliana Ler was investigated. Final leaf length decreased with increasing NT due to a combination of reduced elongation period and reduced elongation rate. Final stem length increased with increasing DT due to increased elongation rate, and decreased with increasing NT due to a decrease in elongation period. Under NT 27 degrees C, however, stem elongation rate increased greatly, resulting in the same final stem length as under NT 12 degrees C. The transition to flowering was accelerated by increasing NT. A linear regression analysis was performed to clarify the relationship between final leaf length, final stem length and flowering time with DIF (DT minus NT) and/or ADT (average daily temperature). For all three variables, the effect of DIF depended on ADT and vice versa. The relationship of final stem length with DIF also depended on the temperature range. Increased cell volume in flower stems developing at DT/NT 22/12 degrees C gave rise to longer and thicker stems compared with stems developing at DT/NT 12/22 degrees C. GC-MS analysis (gas chromatography-mass spectrometry) showed that the endogenous level of IAA was 56 % higher in stems grown under DT/NT 22/12 degrees C compared with DT/NT 12/22 degrees C. Of the 12 gibberellins analysed, however, only the level of non-bioactive GA29 was affected by the temperature treatment.

The Flowering Integrator FT RegulatesSEPALLATA3andFRUITFULLAccumulation inArabidopsisLeaves

“…Does the environment regulate FT function as well? Low ambient temperatures delay flowering time of Arabidopsis plants (Blazquez et al, 2003;Thingnaes et al, 2003). Here, we show that low temperatures reduce the function of FT/TFT.…”

Effect of gibberellic acid on the quality of chrysanthemum (Dendranthema grandiflora L.) cv. Faroe

“…Moreover, the difference between daytime and nighttime temperatures may influence the levels of endogenous gibberellin (Thingnaes et al, 2003).…”

Influence of Diurnal Temperature Range on the Development of Fiber Cells in Flax (Linum usitatissimum)

“…However, in the study by Erwin et al (1994), it was indicated that the stem elongation of L. longiflorum developed at positive DIF was due to only longer but not more cells than at negative DIF. But Thingnaes et al (2003) also found that the elongation and division of stem cells in A. thaliana were both affected by DIFs. The section samples were chosen only from the middle part of the plant stems in this presented study, which could show an approximate estimate for the entire stem of flax.…”

“…From the cellular studies, stems developed under positive DIF have longer cells than under negative DIF, and transverse and longitudinal directions of cell expansions in Arabidopsis thaliana were affected by alternating day and night temperature (Thingnaes et al, 2003). In Lilium longiflorum, Erwin et al (1994) found that stem parenchyma, stem and leaf epidermal cell length were found to increase as the difference (DIF) between DT and NT increased.…”

“…Many studies mainly focus on the effect of DIF on the size and number of plant cells (Erwin et al, 1994;Strøm and Moe, 1997;Thingnaes et al, 2003), but there are little reports of the effect of DIF on the other parameters of plant cells. In flax stem, an important process in the development of phloem fiber cells is the thickening of fiber cell wall (Gorshkova et al, 2003).…”