Articles
INCREASE OF STRESS RESISTANCE IN CROP PLANTS BY USING PHENOLIC COMPOUNDS
In screening biotests the phenolic acetylsalicylic acid (ASA) was selected as the most active compound.
Besides phenolics other stress-related compounds (e.g. aminoalcohols, polyamines, ethylene) act as stress-diminishing substances.
Therefore, the effect of ASA and additionally 2-aminoethanol (2-AE), choline and the ethylene-releasing substance 2-chloro-ethyl-phosphonic acid (CEPA) on growth, water use efficiency (WUE), osmotic pressure and other stress indicators in crops was studied.
By spraying ASA in aqueous solutions (0,2 – 2 mg/plant or 1 – 2 kg/ha) to stressed plants (barley, potatoes, sugar beets) the yield and WUE increased significantly (e.g. in barley up to 20% and in sugar beet ≈10%). The effect of a single ASA application was comparable with 6-treatments of the phytohormone abscisic acid (ABA). Under non stress conditions ASA acted as an antitranspirant and increased the osmotic pressure ( 
). However, after a following drought period in treated plants the rise of the value was lower than in untreated plants (≈50%, significant). The aminoalcohols also stabilized the productivity in crops and decreased the contents of the stress indicators glycine betaine and proline and inhibited senescence progression under drought as well.
A resistance activating principle, relevant for fungi, mamalian and plant cells, is discussed.