Weed Biology and Management (2011) 11, 152-159

Guo-Qing Yang, Fang-Hao Wan, Jian-Ying Guo and Wan-Xue Liu (2011)
Cellular and ultrastructural changes in the seedling roots of upland rice (Oryza sativa) under the stress of two allelochemicals from Ageratina adenophora
Weed Biology and Management 11 (3), 152-159
Abstract: Two sesquiterpene-derivative compounds, 4,7-dimethyl-1-(propan−2-ylidene)-1,4,4a,8a-tetrahydronaphthalene-2,6(1H, 7H)-dione (DTD) and 6-hydroxy-5-isopropyl-3,8-dimethyl−4a,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one (HHO), are the major putative allelochemicals of the aqueous leachates of Ageratina adenophora. A laboratory experiment was conducted, using the hydroponic method, to evaluate the cellular and ultrastructural changes in the seedling roots of upland rice under the stress of DTD and HHO. The subsequent changes were observed in the treated upland rice roots in comparison with their controls. The scanning electron microscopy results showed that the DTD-treated root tip cells turned into an irregular arrangement and shape and that most of them were wizened, with a poor cytoplasm. In the HHO treatment, the root tips had many irregularly shaped cells, with a greater number of sloughing cells, as well as short, wide cells that resulted in spherical and wider, but shorter, roots. At the ultrastructural level, DTD and HHO induced irregularly shaped and lobed nuclei, increased cytoplasmic vacuolation, reduced ribosome density and dictyosomes, and a reduced number of mitochondria in the cells, which indicated limited protein transportation and a reduced capability to export substances for cell development and growth in the upland rice seedling roots. The overall effect of HHO on the upland rice seedlings was more pronounced than that of DTD.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Fang Hao Wan, Wan-Xue Liu

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ageratina adenophora (weed)	Rice (Oryza)