Metabolism and Growth in Arabidopsis Depend on the Daytime Temperature but Are Temperature-Compensated against Cool Nights

Abstract

Diurnal cycles provide a tractable system to study the response of metabolism and growth to fluctuating temperatures. We reasoned that the response to daytime and night temperature may vary; while daytime temperature affects photosynthesis, night temperature affects use of carbon that was accumulated in the light. Three Arabidopsis thaliana accessions were grown in thermocycles under carbon-limiting conditions with different daytime or night temperatures (12 to 24°C) and analyzed for biomass, photosynthesis, respiration, enzyme activities, protein levels, and metabolite levels. The data were used to model carbon allocation and growth rates in the light and dark. Low daytime temperature led to an inhibition of photosynthesis and an even larger inhibition of growth. The inhibition of photosynthesis was partly ameliorated by a general increase in protein content. Low night temperature had no effect on protein content, starch turnover, or growth. In a warm night, there is excess capacity for carbon use. We propose that use of this capacity is restricted by feedback inhibition, which is relaxed at lower night temperature, thus buffering growth against fluctuations in night temperature. As examples, the rate of starch degradation is completely temperature compensated against even sudden changes in temperature, and polysome loading increases when the night temperature is decreased.

Acclimation of metabolism to light in Arabidopsis thaliana: the glucose 6‐phosphate/phosphate translocator GPT2 directs metabolic acclimation

“…However, other factors play important roles in the regulation of starch content and turnover (Pyl et al . 2012; Martins et al . 2013), so it is difficult to interpret these changes in T6P and starch content in isolation.…”

Mechanism of Cytoplasmic mRNA Translation

“…RP gene co-regulation was also noted when monitoring polysome-associated transcript levels. A coordinate shift of Arabidopsis RP mRNAs out of polysome complexes was observed in response to a number of environmental stresses (Kawaguchi et al, 2004;Branco-Price et al, 2005;McIntosh and Bonham-Smith, 2006;Nicolaï et al, 2006;BrancoPrice et al, 2008;Pyl et al, 2012;Tiruneh et al, 2013;. Conversely, coordinated up-regulation of the translation of a large majority of Arabidopsis RP mRNAs was recorded in two mutants of the translational apparatus (eif3h and rpl24b) (Tiruneh et al, 2013).…”

“…For ribosome biogenesis there is the additional energy outlay for rRNA synthesis. It therefore is not surprising that both ribosome biogenesis and global levels of translation are central to energy management (Piques et al, 2009;Pyl et al, 2012;Pal et al, 2013). Situations that limit ATP and GTP availability such as hypoxia, unanticipated darkness and extended nighttime limit RP mRNA translation in Arabidopsis (Branco-Price et al, 2008;Piques et al, 2009;Pal et al, 2013).…”

Positive effects of night warming on physiology of coniferous trees in late growing season: Leaf and root

“…Besides, night warming had positive effect on SLA of both species in the current study (Table 2). Pyl et al (2012) reported that lower temperature could increase leaf thickness, and therefore decrease SLA. In the current study, the air temperature (at 5 cm aboveground) and soil temperature (at 5 cm depth) within the warmed plots increased by an average of 1.95 C and 3.10 C, respectively, compared to the control plots.…”