ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Pollen tubes of Nicotiana sylvestris growing in vitro were used to study growth inhibitory effects of glyphosate, which interferes with the biosynthesis of aromatic amino acids, and of metsulfuron methyl, which reduces the production of the branched-chain amino acids valine, leucine and isoleucine. Using the pollen tube growth test, i.e., photometric quantification of pollen tube growth in vitro, both herbicides were found to inhibit tube growth poorly in the suspension medium but strongly when the medium was replaced by a fresh one 30 min after suspension of pollen. We suggest that the enhanced sensitivity of the suspended pollen resulted from the removal of released amino acids, because addition to the fresh medium of aromatic amino acids or branched-chain amino acids significantly reduced the inhibitory effect of glyphosate or metsulfuron methyl, respectively. Different amino acid compositions were used to analyze the inhibitory concentrations of the herbicides. The data indicated that growing pollen tubes were able to synthesize aromatic or branched-chain amino acids via the shikimate/chorismate pathway or via the acetolactate synthase reaction, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1997.tb01040.x
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