ABSTRACT
This chapter discusses the involvement of the cell wall in responses to water deficit and flooding. The chapter focuses on the role of cell wall yielding in elongation under water deficit and potential regulation by abscisic acid. It discusses cell wall metabolism in the context of structural modifications caused by oxygen deprivation and its regulation by ethylene. The chapter presents that generated from experiments with maize seedlings, a model system that has been the subject of considerable research efforts in both areas. Other oxygen-deprivation responsive genes, xyloglucan endotransglycosylase are strongly induced by anoxia, a condition of total or near-total oxygen deprivation, as well as by flooding. Under anoxic conditions, however, ethylene accumulation and aerenchymal development are inhibited. The chapter summarizes some of the progress in understanding how the cell wall can modulate the plant's response and adaptation to drought and flooding stress.
