SLOWER-CHEMICAL OR FASTER-ELECTRICAL SIGNALING UNDER STRESS IN PLANTS- IS IT THE HARE AND TORTOISE STORY OF A SLOWER SIGNAL WINNING THE RACE

In stress physiology, one of the controversies related to root to shoo t communication under stress, has been whether electrical signals from roots precede the chemical signal, represented;by the predominant pos itive signal, abscisic acid (ABA) which accumulates up to 50 fold in t he roots and xylem sap of stressed plants, Electric signals can be pro duced and transmitted to the shoots 18 cm away from the roots in 25 s when an osmotic stress is given to the roots, However a recent finding that ABA applied to the roots itself can generate electrical signals has only fuelled or exacerbated the controversy. In this paper We have attempted to analyse the relative merits of a faster but apparently s hort distance intense signal, with the slower chemical signals. We hav e critically assessed what appears to be a 'deliberate strategy' of th e plants to spatially separate two diverse but equally effective signa ls. The question we pose in this paper is, can a chemical signal still precede an electrical signal? If true, the plant must devise a differ ent way to release an already available sequestered chemical signal, T his is akin to resolving the classical dilemma of what comes first the chicken or the egg.