Developmental Plasticity at High Temperature

Abstract

Molecular mechanisms controlling the thermal response in Arabidopsis.

Figure 1.

High ambient temperature has effects on plant architecture and development. Representative images are shown for the indicated phenotypes of organs and processes at optimal (21°C) and high (28°C and 30°C) temperatures.

Figure 2.

Organ-specific perception of high temperature and subsequent auxin distribution and downstream signaling. At high temperature, auxin moves from the leaf blade through the petiole toward the hypocotyl. In the latter organ, auxin promotes BR-mediated growth. In the petiole, PIF4 controls PID expression, which impacts phosphorylation-mediated PIN3 localization to control auxin efflux and cell elongation.

Figure 3.

Molecular regulation of thermomorphogenesis. A, Transcriptional regulation by chromatin remodeling. B, Posttranscriptional regulation by alternative splicing. C, Posttranslational regulation by thermal reversion of photoreceptors.

Figure 4.

Light/photoperiod- and phytohormone-dependent thermoresponsive pathways converge at PIF4. Here, light and circadian clock components are integrated with temperature information to mediate thermoresponsive growth, which is controlled by phytohormone signaling. The thermosensory machinery is mainly controlled by phyB, while the roles of other light receptors are still largely elusive. PIF4 mainly mediates thermomorphogenesis by promoting auxin biosynthesis and signaling, while BR signaling plays an important downstream function. For further details on the components of these pathways, see the main text.