Recently, PhyB has been identified to act as a temperature sensor (Jung et al., 2016; Legris et al., 2016), which is interesting since heat stress is known to lead to increased main root growth (Hanzawa et al., 2013). Enter multiple addresses on separate lines or separate them with commas. represses transcriptional and developmental responses to nitrate in This broad range of targets combined with the multitude of signals that impact on PIF stability makes PIF proteins a signaling hub to integrate environmental conditions (Leivar and Monte, 2014; Paik et al., 2017). Competition for light is size-asymmetric: A plant that is only slightly taller than its neighbors can put its leaves above those neighbors, thereby severely limiting their total access to light while itself not being affected at all by its neighbors (Weiner, 1985; Weiner and Thomas, 1986). Author information: (1)Division of Plant Sciences, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 0200, Australia.

These hormones can be transported rootward, where they affect root development. Science 346, 343–346 (2014). Arabidopsis thaliana Studies have accumulated over the past 15 years, and intensified in recent years, showing pronounced effects of light on root physiology and development. 2). Patterson, K . ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Interestingly, light signaling affects auxin biosynthesis and transport, implicating this hormone as a potential integrator of light signaling and root development. Light influences the direction of polar auxin transport by controlling the plasma membrane abundance of PIN proteins (Laxmi et al., 2008; Sassi et al., 2012; Wan et al., 2012; Zhang et al., 2013, 2014). Biol. Roots of dark-grown seedlings are much shorter and have a much thinner diameter than those of light-grown seedlings (Laxmi et al., 2008; Dyachok et al., 2011). (2020), European Journal of Agronomy 37, 897–905 (2004). Annu.

This modulates auxin transport and thus underlies plant phototropism (Fankhauser and Christie, 2015). Light is the energy source for plants as it drives photosynthesis to produce sugars. Another mechanism that controls COP1 activity is its light-based nuclear exclusion that affects HY5 degradation (von Arnim and Deng, 1994; Pacín et al., 2014). The CRY photoreceptors CRY1 and CRY2, upon blue light activation, can bind to SPAs, and this results in reduced COP1-SPA interaction, leading to stabilization of COP1 targets (Lian et al., 2011; Liu et al., 2011; Zuo et al., 2011). Copyright © 2020 by The American Society of Plant Biologists, Plant Ecophysiology, Utrecht University, 3584 CH Utrecht, The Netherlands, Sign In to Email Alerts with your Email Address. The movement of the root away from light sources, or root negative phototropism, is dependent upon blue light perception by PHOTs (Wan et al., 2012). CRY1 and CRY2 act redundantly in promoting flower induction, sensing blue light as input to circadian clock, and stomatal opening in Arabidopsis (Li and Yang, 2007; Galvão and Fankhauser, 2015; Mo et al., 2015). As mentioned above, both root negative phototropism and gravitropism rely on polar auxin transport. The initial perception of gravitropism and phototropism is different, but the downstream signaling events of negative phototropism are very similar to those found in root gravitropism, involving comparable PIN protein and auxin transport dynamics (Friml et al., 2002; Abas et al., 2006; Baster et al., 2013). It is therefore pertinent that ecologists, agronomists, and plant scientists join forces to unravel both the mechanisms and functional implications of shoot-root communication induced by light cues from the environment. Light stimulates the gravitropic response through the increase of flavonol biosynthesis, which increases root auxin levels (Buer and Muday, 2004; Silva-Navas et al., 2016). The effect of UV-B radiation on plant growth is dual. Briefly, FR light reflected by neighbor plants inactivates the PHY photoreceptors, and this relieves their repression of PIF4, PIF5, and PIF7. Upon activation, Pfr translocates from the cytosol to the nucleus, where it interacts with PIFs, modulating their activity (Chen and Chory, 2011; Leivar and Quail, 2011; Xu et al., 2015). Chiou, T. J. All authors performed the experiments and interpreted the results.