Boron stress exposes differential antioxidant responses in maize cultivars (Zea mays L.)

Boron stress is largely influencing the growth and yield of crop plants all around the world. In this scenario, identification of the genotypes that are tolerant to boron stress, understanding the mechanisms behind the tolerance and their application in the breeding programs can open new pathways towards dealing with this global stress. Focusing on this, we compared the diffe- rences in the physiological and biochemical responses of two hybrid maize (Zea mays L.) cultivars, boron tolerant RX 770 and boron susceptible TTM 8119. Both genotypes were subjected to four different B treatments, 0, 2.5, 25 and 50 mg L-1 B. Samples were collected before the application, after 5 days of treatments and 10 days of treatments. Root shoot lengths, dry weights, malondialdehyde (MDA), proline content and activity of antioxidant enzymes were evaluated for different harvest periods. The aim of the study was to determine the role of antioxidant enzymes in providing tolerance to maize genotypes towards B stress. Based on the results, it can be concluded that the activity of SOD, APX, POX and GR enzymes may have a significant role in providing resistance to the maize cultivar RX 770 towards B toxicity, especially at the early stages of plant development. The comparison of the physiological and biochemical mechanism of the tolerant maize genotype with the susceptible one in the presence of the boron stress may provide deep understanding useful for the development of new B tole- rant maize cultivars.