Instituto de Ecología, UNAM. A.P. 70-275. Ciudad Universitaria. México 04510, México.
Plants have to cope with allelochemical stress along with other environmental constraints. Allelochemicals released by some plants can cause and inhibitory/stimulatory effect on the growth of other plants. Studies on the modes of action have shown that either isolated allelochemicals or a mixture of these can affect photosynthesis, cell division, respiration, ion uptake, hormone balance, water relations, and membrane permeability. We are studying the modes of action of allelochemicals through the effects on protein and gene expression, identifying those gene products, which either are affected at transcriptional or translational level by the allelochemical stress. These molecular approaches have been used extensively to understand the plant response to water, salt, temperature stress among other environmental factors. Currently we are looking at differences on the protein pattern expression of some crops affected by aqueous leachates from different allelopathic plant species. 2D-PAGE was used to detect differences on protein patterns. With this technique we have identified proteins that are diminished, enhanced, or appeared the novo. Proteins of high, medium and low molecular weight are affected by the allelochemical stress. Maize and beans plants have shown the most significant changes on protein expression. N-terminal sequencing is to be performed on some of these affected proteins. On the other hand, we are doing some differential screening to identify genes that might be altered. Our objective, using these approaches, is to gain more understanding of the different processes that might be involved during an allelochemical stress. We believe that not only a single metabolic process but also several ones might be affected by this stress.