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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Available from: Abidur Rahman, Oct 04, 2015
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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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    ABSTRACT: Ethylene is a simple two carbon atom molecule with profound effects on plants. There are quite a few review papers covering all aspects of ethylene biology in plants, including its biosynthesis, signaling and physiology. This is merely a logical consequence of the fascinating and pleiotropic nature of this gaseous plant hormone. Its biochemical precursor, 1-aminocyclopropane-1-carboxylic acid (ACC) is also a fairly simple molecule, but perhaps its role in plant biology is seriously underestimated. This triangularly shaped amino acid has many more features than just being the precursor of the lead-role player ethylene. For example, ACC can be conjugated to three different derivatives, but their biological role remains vague. ACC can also be metabolized by bacteria using ACC-deaminase, favoring plant growth and lowering stress susceptibility. ACC is also subjected to a sophisticated transport mechanism to ensure local and long-distance ethylene responses. Last but not least, there are now a few exciting studies where ACC has been reported to function as a signal itself, independently from ethylene. This review puts ACC in the spotlight, not to give it the lead-role, but to create a picture of the stunning co-production of the hormone and its precursor.
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    • "PANGLOSS1, an atypical LRR-RLK in maize (Zea mays), was found to physically associate with RHO OF PLANTS GTPase in maize extracts (Humphries et al., 2011). FEI1, a kinaseactive Arabidopsis LRR-RLK, does not require kinase activity to rescue the fei1 mutation, and it directly interacts with 1-aminocyclopropane-1-carboxylic acid synthase (Xu et al., 2008). XopN, a virulence factor of Xanthomonas campestris that is translocated into plant cells, is able to bind to the cytosolic domain of TOMATO ATYPICAL RECEPTOR-LIKE KINASE1, an atypical LRR-RLK (Kim et al., 2009). "
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