Sentinels at the wall: cell wall receptors and sensors

Abstract

Contents Summary 7 Introduction 8 Cell expansion and plant growth 8 Cell wall responses to stress 11 Pathogen attack and mechanical stimuli 11 Lessons from yeast 12 Candidate sensors and receptors in plants 14 Conclusions 17 Acknowledgements 17 References 17 Summary The emerging view of the plant cell wall is of a dynamic and responsive structure that exists as part of a continuum with the plasma membrane and cytoskeleton. This continuum must be responsive and adaptable to normal processes of growth as well as to stresses such as wounding, attack from pathogens and mechanical stimuli. Cell expansion involving wall loosening, deposition of new materials, and subsequent rigidification must be tightly regulated to allow the maintenance of cell wall integrity and co‐ordination of development. Similarly, sensing and feedback are necessary for the plant to respond to mechanical stress or pathogen attack. Currently, understanding of the sensing and feedback mechanisms utilized by plants to regulate these processes is limited, although we can learn from yeast, where the signalling pathways have been more clearly defined. Plant cell walls possess a unique and complicated structure, but it is the protein components of the wall that are likely to play a crucial role at the forefront of perception, and these are likely to include a variety of sensor and receptor systems. Recent plant research has yielded a number of interesting candidates for cell wall sensors and receptors, and we are beginning to understand the role that they may play in this crucial aspect of plant biology.

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

“…This suggests that fei1 fei2 perturbs the biosynthesis or function of cellulose. Consistent with this, the roots of fei1 fei2 seedlings grown in nonpermissive conditions produced ectopic lignin ( Figure 1H), which is generally correlated with a decreased level of crystalline cellulose (Humphrey et al, 2007). We further analyzed cellulose synthesis by measuring the incorporation of [ 14 C]glucose into crystalline and noncrystalline cellulosic cell wall fractions of excised root tips.…”

Exploring the Mechanism of Physcomitrella patens Desiccation Tolerance through a Proteomic Strategy

“…This enzyme catalyzes the synthesis of rhamnose, which is a prominent component of cell wall pectin. In angiosperms, pectins have been linked to communication between cell wall and cytoplasm, particularly during periods of stress (Humphrey et al, 2007), although it remains to be demonstrated to what extent this holds for bryophytes. Evidently, P. patens survives desiccation with several strategies; how the moss combines these strategies still needs to be determined.…”

Solutions for a local equation of anisotropic plant cell growth: an analytical study of expansin activity

“…Expansins are a superfamily of plant proteins involved in cell wall extension and stress relaxation, abscission, fruit softening, the response to biotic and abiotic stresses, and development of leaf, floral organ, root hairs and grain size [8,9,[17][18][19][20][21][22][23][24][25][26][27][28]. Expansins are subdivided into four families: a-expansin, b-expansin, expansin-like A and expansin-like B [29].…”