Two Leucine-Rich Repeat Receptor Kinases Mediate Signaling, Linking Cell Wall Biosynthesis and ACC Synthase in Arabidopsis

Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA.
The Plant Cell (Impact Factor: 9.34). 12/2008; 20(11):3065-79. DOI: 10.1105/tpc.108.063354
Source: PubMed


The plant cell wall is a dynamic structure that changes in response to developmental and environmental cues through poorly understood signaling pathways. We identified two Leu-rich repeat receptor-like kinases in Arabidopsis thaliana that play a role in regulating cell wall function. Mutations in these FEI1 and FEI2 genes (named for the Chinese word for fat) disrupt anisotropic expansion and the synthesis of cell wall polymers and act additively with inhibitors or mutations disrupting cellulose biosynthesis. While FEI1 is an active protein kinase, a kinase-inactive version of FEI1 was able to fully complement the fei1 fei2 mutant. The expansion defect in fei1 fei2 roots was suppressed by inhibition of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, an enzyme that converts Ado-Met to ACC in ethylene biosynthesis, but not by disruption of the ethylene response pathway. Furthermore, the FEI proteins interact directly with ACC synthase. These results suggest that the FEI proteins define a novel signaling pathway that regulates cell wall function, likely via an ACC-mediated signal.

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    • "Phytohormones cytokinin and brassinosteroids regulate ethylene biosynthesis by stabilizing ACS5 (Chae et al., 2003; Hansen et al., 2009). Two receptor like kinases FEI1 and FEI2 interact with ACSs, linking the cell-wall biosynthesis with ethylene production during root growth (Xu et al., 2008). In addition , ACS4 (type II) and ACS7 (type III) are regulated by XBAT32 E3 ligases (Nodzon et al., 2004; Prasad and Stone, 2010; Prasad et al., 2010; Lyzenga et al., 2012), and ACS4 and ACS5 are the targets of E3 ligases, for degradation through ubiquitin-26S proteasome (Christians et al., 2009; Lyzenga et al., 2012). "
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    • "(Bar = 1 cm). Figure reproduced from Xu et al. (2008). "
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