Calcium-dependent tolerant response of cell wall in maize mesocotyl under flooding stress

Abstract

The aim of the present study was to find out the effect of calcium on flooded maize seedlings by anatomical and ultra-structural analyses and by measuring the enzyme activity and gene expression of polygalacturonase (PG) and superoxide dismutase (SOD). For this, maize seeds were placed to germinate in germination paper saturated with CaCl2 0.75 %. Then, 4-day-old seedlings were subjected to flooding in the presence or absence of CaCl2. Mesocotyl sections were sampled daily for the anatomical and ultra-structural analyses, RT-qPCR and activity of SOD and PG. The results showed that the presence of calcium in the flooding buffer increases the tolerance of maize seedlings by 1 day when compared to seedlings flooded in the absence of this element. The reason for this longer survival is that calcium maintains the integrity of the cell wall and attenuates the effects of oxidative stress. Owing to this fact, the seedlings remained alive and firm for up to 7 days.