PMID:20530756

Citation	Leiber, RM, John, F, Verhertbruggen, Y, Diet, A, Knox, JP and Ringli, C (2010) The TOR pathway modulates the structure of cell walls in Arabidopsis. Plant Cell 22:1898-908
Abstract	Plant cell growth is limited by the extension of cell walls, which requires both the synthesis and rearrangement of cell wall components in a controlled fashion. The target of rapamycin (TOR) pathway is a major regulator of cell growth in eukaryotes, and inhibition of this pathway by rapamycin reduces cell growth. Here, we show that in plants, the TOR pathway affects cell wall structures. LRR-extensin1 (LRX1) of Arabidopsis thaliana is an extracellular protein involved in cell wall formation in root hairs, and lrx1 mutants develop aberrant root hairs. rol5 (for repressor of lrx1) was identified as a suppressor of lrx1. The functionally similar ROL5 homolog in yeast, Ncs6p (needs Cla4 to survive 6), was previously found to affect TOR signaling. Inhibition of TOR signaling by rapamycin led to suppression of the lrx1 mutant phenotype and caused specific changes to galactan/rhamnogalacturonan-I and arabinogalactan protein components of cell walls that were similar to those observed in the rol5 mutant. The ROL5 protein accumulates in mitochondria, a target of the TOR pathway and major source of reactive oxygen species (ROS), and rol5 mutants show an altered response to ROS. This suggests that ROL5 might function as a mitochondrial component of the TOR pathway that influences the plant's response to ROS.
Links	PubMed PMC2910960 Online version:10.1105/tpc.109.073007
Keywords	Amino Acid Sequence; Arabidopsis/cytology; Arabidopsis/genetics; Arabidopsis/metabolism; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Cell Wall/metabolism; Chromosome Mapping; Cloning, Molecular; DNA, Plant/genetics; Gene Expression Regulation, Plant; Genotype; Mitochondria/metabolism; Molecular Sequence Data; Mutagenesis; Phenotype; Plant Roots/cytology; RNA, Transfer/genetics; Reactive Oxygen Species/metabolism; Saccharomyces cerevisiae/metabolism; Sequence Alignment; Signal Transduction; Sirolimus/pharmacology
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
YEASO:E7NHF2		GO:0032007: negative regulation of TOR signaling	ECO:0000315:		P		Figure 4B shows that when Saccharomyces cerevisiae loses the gene Ncs6p, it loses the ability to grow when grown with rapamycin.	complete CACAO 9676
ARATH:F4IU18		GO:0032006: regulation of TOR signaling	IMP: Inferred from Mutant Phenotype:	P	Figure 4 shows that when Ncs6p is removed, there is no growth in the presence of rapamycin but when rol5 is added, growth begins again.	complete CACAO 9678
ARATH:F4IU18		GO:0000302: response to reactive oxygen species	IMP: Inferred from Mutant Phenotype:	P	Figure 7 shows that the rol5-1 mutant is hypersensitive to hydrogen peroxide and hyposensitive to the ROS scavenger CuCl2, indicating the importance of ROL5 in the sensing of and response to ROS.	complete CACAO 10123

References

See Help:References for how to manage references in GONUTS.