The growth of plant is greatly influenced by environmental conditions and in particular by stress. Biotic stress is caused by other living organisms such as fungi, bacteria, nematodes, and insects while abiotic stress results from environmental factors such as the water availability, water quality, light quality, temperature, ozone, and heavy metals.
Plants are sessile organisms, not having the ability to escape from stress, and have therefore, in the course of evolution, developed molecular mechanisms which permit them to adapt to unfavourable environmental conditions. The knowledge of the molecular mechanisms that are the basis for this tolerance has the potential to contribute to the development of new plant varieties and new cultivation methods to increase productivity.
Some methods for stress tolerance involve the regulation of gene expression by transcription factors (TF) and one such class of transcription factor are the HD-Zip proteins.

The genetic modification of transcription factor expression levels offers advantages in that it is possible to influence the expression of numerous genes instead of only one. Our group have obtained tomato lines where the these genes are over expressed (either in a constitutive manner or regulated by a promoter activated only under stress) and are being evaluated for their performance in conditions of salt and water stress as well as their tolerance to pathogenic attacks by bacteria and viruses. Furthermore the gene involved in the cellular metabolic regulation of proline, glycine betaine, and arginine was transformed into tomato plants in order to produce plants resistant to abiotic stress.
This study was carried out within the European projects TF-Stress (Transciption factors controlling plant responses to environmental stress conditions) and ROST (Regulation of osmotolerance) as well as the Italian national project FIRB and involves numerous national and international collaborations.

For more information contact: Dr. Rina Iannacone