W ater scarcity in soil induces drought stress that leads to lower photosynthetic efficiency and reduced production of plant biomass (Chaves et al., 2009). Besides, water shortage causes oxidative stress, osmotic stress and cellular damage in plants particularly in chloroplasts (Wang et al., 2003).

Plants are exposed to various biotic and abiotic stresses. Some of the abiotic stresses are drought, salinity, extreme temperatures and pollutants. These stresses negatively affect plant growth and development. The present study was designed to investigate the effects of drought stress on biomass production and chlorophyll, proteins and proline contents of two different hybrids of maize plants (Zea mays L.). The experiment was conducted in randomized block design with four replicates in pots. Three weeks old plants were challenged with drought stress by skipping irrigation. After drought stress of two weeks the plants were harvested and were subjected to various morphometric, physiological and biochemical assays. Both hybrids exhibited significant reduction in biomass production under drought stress. However, this loss was relatively lower in hybrid M-32. Drought stress caused reduction in root and shoot length, chlorophyll contents and photosynthesis activity. The chlorophyll a/b ratio increased in hybrid M-435 under water deficit conditions. Contrastingly it was decreased in M-32 due to drought stress. The total soluble proteins (TSPs) and Proline concentration were greater in M-435 under drought conditions as compared to control. While M-32 exhibited relatively lower quantity of TSPs and Proline when grown under drought stress. The Proline concentration, TSPs and Chlorophyll a/b ratio was relatively higher in M-435 grown under drought stress that indicated its potential for drought tolerance. The current study revealed that maize plants may exhibit drought tolerance by adapting variations in their morphology, anatomical structures and metabolic and physiological profile.