Defensive forwards: stress-responsive proteins in cell walls of crop plants

As the vital component of plant cell wall, proteins play important roles in stress response through modifying wall structure and involving in wall integrity signaling. However, the potential of cell wall proteins (CWPs) in improvement of crop stress tolerance has probably been underestimated. Recently, we have critically reviewed the predictors, databases and cross-referencing of subcellular locations of possible CWPs in plants (Briefings in Bioinformatics 2018;19:1130-1140). In this study, taking maize (Zea mays) as an example, we retrieved 1873 entries of probable maize CWPs recorded in UniProtKB. As a result, 863 maize CWPs are curated and classified as 59 kinds of protein families. By referring to GO annotation and gene differential expression in Expression Atlas, we highlight the potential of CWPs as defensive forwards in abiotic and biotic stress responses. In particular, several CWPs are found to play key roles in adaptation to many stresses. String analysis also reveals possibly strong interactions among many CWPs, especially those stress-responsive enzymes. The results allow us to narrow down the list of CWPs to a few specific proteins that could be candidates to enhance maize resistance.