Hormonal Changes and Root Growth in Crops Subjected to Waterlogging

Abstract

In waterlogged soils, water replaces air in the soil. Waterlogging is a serious problem which occurs whenever the soil is so wet that there is insufficient oxygen in the soil for crop roots to be unable to normal respiration. Roots are directly and firstly influenced oxygen deprivation caused by waterlogging. Upon waterlogging, plant root growth can be inhibited and caused root death. Responses of crops to waterlogging vary depending on the occurring time, length of time the soil remains saturated and the genotype of the crop, species and variability within species. Formation of aerenchyma and adventitious roots are the most common reactions of the crops to hypoxia and anoxia conditions under longer periods of waterlogging. Root systems deprived of oxygen are poor reserves of mineral nutrients for both root and shoot systems. The reduction in stomatal aperture is a major cause of the initial decline in photosynthetic capacity of waterlogged crops. Another effect of waterlogging is to inhibit the production of certain plant hormones which enable to growth and leaf expansion. Besides, ethylene can increase plant survival when the level of oxygen diminished in the root zone. In this article, the changes and hormonal responses that occur in the roots of field crops under waterlogging conditions were investigated.

Keywords

• Aerenchyma
• anoxia
• hypoxia
• ethylene
• waterlogging