The role of lectins and HD-ZIP transcription factors in isoprenoid based plant stress responses

It was over half a century ago when the overwhelming array of chemicals found in plants was postulated to be more than just by-products of primary metabolism. Ever since, extensive research has been conducted on plant secondary metabolites which are now known to be the end points of sophisticated survival mechanisms that plants have developed as a response to various kinds of stresses. Stress, defined by its negative effect on the growth and development of an individual, can be internal (metabolic or genetic), external (biotic or abiotic), permanent or acute. To cope, organisms must develop tolerance, resistance or avoidance mechanisms. Isoprenoids, often released as volatiles from plants, constitute the most diverse groups of natural products and play an essential part in plant defense systems, both directly (as emitted volatiles) and indirectly (the principle of inviting friends to feast on foes). Research over the last decade has resulted in a significant improvement in our understanding of the isoprenoid biosynthesis but there remains much to learn about the complex regulatory network controlling the various steps of these pathways and their dynamic co-ordination. Here we identify novel plant proteins and provide a putative role for them in isoprenoid based stress responses, along with insights into future perspectives for research.