Environmental factors affecting the cyanogenic potential of flax seedlings

The levels of cyanogenic glucosides (linamarin and lot-australin) and the activity of linamarase were studied in 5-day old seedlings of oil flax (Linum usitatissimum L., cv. LCSD 200) under different environmental conditions. White light enhanced the cyanoglucosides content, and this effect depended on its intensity and the time of exposure. The level of cyanoglucosides rose with temperature, and it reached the highest level at the highest temperature (30 degreesC). Linamarase (EC. 3.2.1.21) activity was the highest at 20 degreesC, especially in light-grown seedlings. Lower enzyme activity at the extreme temperature (15 and 30 degreesC) was observed. Water stress (low water potential, psi = -0.34 MPa) reduced by more than twice the cyanoglucoside level and linamarase activity. The possible protective, or/and regulatory roles of cyanogenic glucosides was discussed.