Ouzounidou G, Moustakas M, Eleftheriou E P
Department of Botany, Aristotle University of Thessaloniki, P.O. Box 109, Thessaloniki 540 06, Greece.
Arch Environ Contam Toxicol. 1997 Feb;32(2):154-60. doi: 10.1007/s002449900168.
The effects of a 7-day exposure of 3-day-old wheat plantsto increasing Cd concentrations are described, with special attention beinggiven to chloroplast ultrastructural changes, chlorophyll fluorescenceresponses, chlorophyll and nutrient concentration changes as well as growthchanges of the whole plant. The plants treated with 1 mM Cd showed symptomsof heavy metal toxicity. The root, shoot-leaf length and the root, shoot-leafbiomass progressively decreased with increasing Cd in nutrient solution andin 1 mM of Cd an almost complete inhibition of growth was found. Shoot-leafCd accumulation increased under Cd-treatments, while a Fe, Mg, Ca, and Kdecline in the above ground parts was observed. The growth reduction and theinhibition of chlorophyll content and photosynthesis observed in the upperplant parts seemed principally due to indirect Cd effects on the content ofessential nutrients. Cadmium treatment was shown to damage the structure ofchloroplasts, as manifested by the disturbed shape and the dilation of thethylakoid membranes. These ultrastructural changes suggest that Cd probablyinduced premature senescence.
描述了3日龄小麦植株暴露于浓度不断增加的镉中7天的影响，特别关注叶绿体超微结构变化、叶绿素荧光响应、叶绿素和养分浓度变化以及整株植物的生长变化。用1 mM镉处理的植株表现出重金属毒性症状。随着营养液中镉含量的增加，根、茎叶长度以及根、茎叶生物量逐渐减少，在1 mM镉处理下，几乎完全抑制了生长。镉处理下茎叶镉积累增加，同时地上部分铁、镁、钙和钾含量下降。植株上部生长减少以及叶绿素含量和光合作用受到抑制，似乎主要是由于镉对必需养分含量的间接影响。镉处理显示会破坏叶绿体结构，表现为类囊体膜形状紊乱和扩张。这些超微结构变化表明镉可能诱导了早衰。
