Cell wall remodeling under abiotic stress

Abstract

Plants exposed to abiotic stress respond to unfavorable conditions on multiple levels. One challenge under drought stress is to reduce shoot growth while maintaining root growth, a process requiring differential cell wall synthesis and remodeling. Key players in this process are the formation of reactive oxygen species (ROS) and peroxidases, which initially cross-link phenolic compounds and glycoproteins of the cell walls causing stiffening. The function of ROS shifts after having converted all the peroxidase substrates in the cell wall. If ROS-levels remain high during prolonged stress, OH°-radicals are formed which lead to polymer cleavage. In concert with xyloglucan modifying enzymes and expansins, the resulting cell wall loosening allows further growth of stressed organs.

The Maize MID-COMPLEMENTING ACTIVITY Homolog CELL NUMBER REGULATOR13/NARROW ODD DWARF Coordinates Organ Growth and Tissue Patterning

“…The levels of hemicellulosic-based arabinose are increased in nod-1, while hemicellulosic xylan and cellulose levels are unchanged (Supplemental Figure 4E). Both transcription and cell wall sugar composition are consistent with a stress response (Le Gall et al, 2015;Tenhaken, 2015). The exception is the reduction in lignin content observed by phloroglucinol staining in leaf and stem tissues (Supplemental Figures 4A to 4D) and correlated with the downregulation of the phenylpropanoid category ( Figure 7B).…”

Differentially Regulated Orthologs in Sorghum and the Subgenomes of Maize

“…We used MapMan (Usadel et al, 2009) to visualize the patterns of expression within particular functional categories among DE2 genes as well as DE1 maize and DE1 sorghum genes. As expected, genes related to cell wall growth, a marker for plant growth, were downregulated in both species in the cold, including xyloglucosyl transferase (Sobic.001g538000 and GRMZM2G388684) and leucine-rich repeat family protein (Sobic.003g205600 and GRMZM2G333811) genes (Cui et al, 2005;Pearce, 2001;Tenhaken, 2014). Genes involved in lipid metabolism were upregulated in both species, including glycerol-3-phosphate acyltransferase 8 (Sobic.009g162000 and GRMZM2G166176), diacylglycerol kinase (Sobic.006g230400 and GRMZM2G106578), choline-phosphate cytidylyltransferase (Sobic.001g282900 and GRMZM2G132898), MGDG synthase (Sobic.004g334000 and GRMZM2G178892, Sobic.007g211900 and GRMZM2G141320), glycerophosphodiester phosphodiesterase (Sobic.007g190700 and GRMZM2G064962, Sobic.004g157300 and GRMZM2G018820), and fatty acid elongation acyl-CoA ligase (Sobic.004g015400 and GRMZM2G120539) genes.…”

Orthodox Seeds and Resurrection Plants: Two of a Kind?

“…Cell walls in seeds dry out during maturation, and a number of these walls contain higher arabinan levels than the vegetative tissues of the mother plant (Gomez et al, 2009;Tenhaken, 2015). During germination, the arabinan is metabolized and generates the precursors required for the biosynthesis of wall polymers and arabinogalactan proteins (Gomez et al, 2009;Tenhaken, 2015).…”

“…During germination, the arabinan is metabolized and generates the precursors required for the biosynthesis of wall polymers and arabinogalactan proteins (Gomez et al, 2009;Tenhaken, 2015). Large quantities of arabinans found in maturing Arabidopsis seeds are degraded during germination, suggesting that they play a role in seed desiccation and are metabolized after germination, as they are no longer required (Gomez et al, 2009).…”