Protein Analysis of Abiotic and Biotic Stress Response during Cotton Vegetative Growth

In cotton, seed germination, seedling establishment and vegetative growth are the stages of the plant most sensitive to abiotic and biotic stresses. Despite good management practices and the capacity of the plant to adapt quickly to environmental changes, stress events may reduce cell activity and plant growth to a minimum, leading to a disappointing production season. The analysis of stress-responsive proteins is an important route towards the discovery of genes conferring stress tolerance and disease resistance and their use in molecular breeding programs. This work reviews current knowledge obtained by traditional hypothesis-driven research of proteins expressed during abiotic stress such as drought, salinity and temperature extremes and biotic stress such as insects and pathogens. It further introduces new exploratory data driven research through the use of proteomics. The proteins have been identified in cotton using these approaches have a range of functions in stress responses. These include detection of stress by cell surface proteins and resistance gene products; signaling cascades; transcription factors; physiological responses such as changes in membrane fluidity and water and ion channels; and disease responses such as pathogenesis-related proteins and enzymes involved in phytoalexin synthesis. The potential for manipulating different types of proteins to enhance resistance to stress is discussed. This review also provides an outline of the challenges encountered when initiating proteome analysis in a non-model plant species.