Molecular Genetic Approaches to Improving Heat and Drought Stress Tolerance in Crop Plants

Abstract

Recent advances in plant biotechnology may play crucial roles in the development of superior crop plants with better environmental stress tolerance and higher yield potential under stressful conditions. Appropriate research strategies are, however, required to harvest the fruits of this recent explosion of information in the field of molecular genetics. Most crop plants such as wheat, rice, corn, sorghum, soybean and cotton suffer from heat and drought stress conditions during their normal growth cycles and their yield as well as quality are seriously affected by such environments. Designed genetic modifications of existing crop plants may provide a suitable means to develop plants with improved productivity and quality in stressful environments. However, no cultivar in any crop species has yet been developed and released by introducing a specific stress tolerance gene or by using a molecular marker-aided selection. The main reason for this deficiency is the polygenic nature of the stress tolerance traits which makes it difficult to identify a single gene conferring stress tolerance in crop plants. Most of the data collected in stress tolerance research is correlative and cause and effect relationships have rarely been addressed. In this review, we present the current status of knowledge in the field of molecular biology and molecular markers for heat and drought stress tolerance in crop plants.