Signaling pathways from the chloroplast to the nucleus

Abstract

Genetic and physiological studies have to-date revealed evidence for five signaling pathways by which the chloroplast exerts retrograde control over nuclear genes. One of these pathways is dependent on product(s) of plastid protein synthesis, for another the signal is singlet oxygen, a third employs chloroplast-generated hydrogen peroxide, a fourth is controlled by the redox state of the photosynthetic electron transport chain, and a fifth involves intermediates and possibly proteins of tetrapyrrole biosynthesis. These five pathways may be part of a complex signaling network that links the functional and physiological state of the chloroplast to the nucleus. Mutants defective in various steps of photosynthesis reveal a surprising diversity in nuclear responses suggesting the existence of a complex signaling network.

EXECUTER1- and EXECUTER2-dependent transfer of stress-related signals from the plastid to the nucleus ofArabidopsis thaliana

“…The EXECUTER1-and EXECUTER2-dependent signaling in the flu mutant bears a striking resemblance to retrograde signaling that has been shown to play a central role in controlling gene expression in the nucleus and the plastid (21,22). Chloroplast proteins are encoded by both nuclear and plastid genomes (23).…”

“…Initially the biological impact of plastid-derived signals had been considered to be confined to the fine-tuning and coordination of nuclear and chloroplast gene activities that are required for the optimization and protection of chloroplast-specific functions such as e.g., photosynthesis (21,22,25). The results of our work demonstrate that the primary function of singlet oxygen in the flu mutant does not seem to be the control of chloroplast performance but the activation of a stress-related signaling cascade that encompasses numerous signaling pathways known to be activated by pathogen attack, wounding, light and drought stress (28)(29)(30).…”

Responses ofEmiliania huxleyi(Prymnesiophyceae) to step changes in photon flux density

“…These signals initiate the feedback from the photosynthetic machinery to control chloroplast and nuclear gene expression. These include changes in the redox state of components of the photosynthetic electron transfer chain, changes in the transthylakoid pH gradient, and changes in the redox state of the stroma, in addition to red-light and blue-light sensors (Beck, 2005;Fey et al, 2005;Wilhelm et al, 2006). In the chlorophyte Dunaliella tertiolecta both state transitions, which result in the short-term redistribution of excitation energy between photosystems I and II, and photoacclimation of cellular pigment content appear to be driven largely by the redox state of the plastoquinone pool (Escoubas et al, 1995).…”

Molecular components of stress-responsive plastid retrograde signaling networks and their involvement in ammonium stress

“…In particular, the regulation of plastid retrograde signaling in the expression of photosynthesis-associated nuclear genes and those related to chloroplast development has been extensively studied. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] More recently, several plastid retrograde signaling pathways have been identified to regulate the expression of stress-related nuclear genes during several stresses such as high light, drought, wounding, heat, and excess ammonium. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] Based on the new stress-responsive plastid retrograde signaling pathways just reported in 2012 alone, this review will focus on properties of currently proposed molecular components in the plastid retrograde signaling network under stress.…”