Phytotoxicity mechanisms of two coumarin allelochemicals from Stellera chamaejasme in lettuce seedlings
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- 作者：Zhiqiang Yan ; Dandan Wang ; Haiyan Cui ; Denghong Zhang…
- 关键词：Cell viability ; Daphnoretin ; Phytotoxicity ; Lettuce ; Mitosis ; Reactive oxygen species ; Umbelliferone
- 刊名：Acta Physiologiae Plantarum
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：38
- 期：10
- 全文大小：1,141 KB
- 刊物主题：Plant Physiology; Plant Genetics & Genomics; Plant Biochemistry; Plant Pathology; Plant Anatomy/Development; Agriculture;
- 出版者：Springer Berlin Heidelberg
- ISSN：1861-1664
- 卷排序：38
文摘
Stellera chamaejasme, a perennial weed which is an ecological threat, is widely distributed in some grasslands of Central and Eastern Asia. Our previous studies have identified several allelochemicals including two coumarins (umbelliferone and daphnoretin), from S. chamaejasme, and confirmed that allelopathy contributed to the competitive behavior of this weed. In this study, the inhibitory effects of umbelliferone and daphnoretin on lettuce seedlings and the mechanisms of their phytotoxicity were investigated. Results showed that shoot and root elongation and fresh weight of lettuce seedlings were effectively inhibited by umbelliferone in a concentration-dependent manner. Daphnoretin showed a weaker phytotoxicity. Both of the coumarins arrested the mitosis process in lettuce root tips and induced proline overproduction. Additionally, loss of cell viability and overproduction of reactive oxygen species in lettuce root cells were found after treatments with umbelliferone. Moreover, umbelliferone caused lipid peroxidation. These results suggested that umbelliferone displayed stronger phytotoxicity than daphnoretin on lettuce growth, and that the two coumarins had different mechanisms of phytotoxicity. That of daphnoretin was mainly dependent on its inhibitory effects on mitosis. Umbelliferone caused membrane lipid peroxide formation and cell death by inducing ROS overproduction, and impacted cell division, which resulted in growth inhibition of the receptor plant.