Physiological and molecular responses of maize (Zea mays l.) plants to drought and rehydration

Abstract

Physiological and molecular responses of maize seedlings (Zea mays L. cv. Troinaya sladost) to 5-d drought and rehydration for 48 h were investigated. Plant water status was determined by a new method of water potential measurement in mesophyll cells' apoplast in substomatal cavity (ψwa). Drought caused the changes in water status, plant growth, the rates of photosynthetic CO2/H2O gas exchange, and metabolism of carbohydrates and proline. The increase in carbohydrate and proline content under drought was observed simultaneously with the decline in ψwa. Rewatering of seedlings for 24 and 48 h resulted in restoration of growth, rapid increase in ψwa as well as in the rates of photosynthetic gas exchange, and a sharp decline in the content of soluble sugars and proline. Data on close correspondence between the changes in osmolyte content and ψwa under drought and recovery support the assumption that osmolytes might participate in regulation of ψwa.