Hydrogen Peroxide Involved in Root Development under Zinc Deficiency Stress in Maize (Zea mays.L)

Zinc (Zn) is one of the essential micronutrients for plant growth and development. The objective of this study is to investigate whether hydrogen peroxide (H₂O₂ )involve in plant root development under Zn deficiency. The maize variety ZD958 was selected to grow with nutrient solution culture. Roots and shoots at 10 and 15 days of transplant after the treatments of 0 (–Zn) and 1 μM (+Zn) supply. Zn deficiency reduced crown root growth. Accumulation of H₂O₂ in the meristematic and elongation zone of crown roots and lateral roots was found under Zn deficiency by chemical staining and fluorescent probe detection. The exogenous addition of H₂O₂ scavenger DMTU did not affect lateral root development while reduced the inhibition of crown root by Zn deficiency. In contrast, exogenous addition of H₂O₂ and catalase inhibitor increased the accumulation of H₂O₂ in roots and inhibited crown root growth. Transcriptomics and proteomics analysis showed that some key genes and proteins related to antioxidant enzymes and cell elongation were down-regulated in Zn deficient roots. It is suggested that hydrogen peroxide might involve in the inhibition of crown root development in maize subjected to Zn deficiency stress.