Soltys Dorota, Rudzińska-Langwald Anna, Kurek Wojciech, Szajko Katarzyna, Sliwinska Elwira, Bogatek Renata, Gniazdowska Agnieszka
Plant Breeding and Acclimatization Institute, Młochów Research Center, Platanowa 19, 05-831 Młochów, Poland.
Department of Botany, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland.
J Plant Physiol. 2014 May 1;171(8):565-75. doi: 10.1016/j.jplph.2014.01.004. Epub 2014 Mar 20.
Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses.
氰胺（CA）是由四种豆科植物产生的具有植物毒性的化合物：毛苕子、草藤、紫花苕子和刺槐。其毒性归因于复杂的活性，这种活性涉及细胞结构和生理过程的改变。迄今为止，CA主要在双子叶植物中进行了研究。本研究的目的是研究CA对代表单子叶植物的玉米（Zea mays）根系生长的影响。CA（3mM）减少了玉米幼苗根尖边缘细胞的数量并降解了它们的原生质体。然而，除了液泡化增加外，CA并未引起其他根细胞细胞器结构的任何显著变化。CA对细胞周期活性、核内复制强度以及细胞周期蛋白CycA2、CycD2和组蛋白HisH3基因表达的修饰也证明了其毒性。相比之下，微管的排列未被CA改变。用CA处理玉米幼苗并没有完全阻止有丝分裂活性，尽管分裂细胞的频率降低了。此外，长时间的CA处理增加了根尖内多倍体细胞的比例。细胞学畸形伴随着根细胞氧化应激的诱导，表现为H2O2积累增强。将玉米幼苗暴露于CA导致生长素浓度增加并刺激乙烯释放。综上所述,这些发现表明CA对根系生长的抑制可能是应激诱导的形态发生反应的结果。
