PRODUCTION OF DISEASE-TOLERANT AND STRESS -TOLERANT PLANTS BY INCREASING THEIR JUVENILITY AND ANTIOXIDANT CAPACITY

Results dealing with the correlation between the physiological state o r antioxidant capacity and resistance of plants against necrotic disea ses and environmental stresses are reviewed. Plants with higher juveni lity/slower senescence have generally not only elevated enzymatic and non-enzymatic antioxidant activity, but also augmented tolerance to ne crotic diseases and environmental stresses. This hypothesis is support ed by the results showing that in vitro selected, mutant or transgenic plants wiht elevated antioxidant activity (SOD, catalase etc.) and/or juvenility (high cytokinin or low ethylene production) have increased tolerance to necrotrophic pathogens and environmantal stresses like f rost, heat, heavy metals, herbicides, ozone etc. The application of th e above methods could provide beneficial stress-tolerant initial mater ials for the practical breeding programs.