Enantioselective Phytotoxicity and the Relative Mechanism of Current Chiral Herbicides.
BACKGROUND
Regardless of the achievable of chiral switch, most of the chiral nature agrochemical is still sold as racemate or enantiomer-enriched pesticides. Herbicides, accounted for a large proportion in pesticide market, are of great concern due to the frequent occurrence in environment and the structure selective phyto-biochemical impact on plants.


METHODS
We give a systematic search on the literature database and included approximately 50 papers which were related to the review. We do careful categories for the chiral herbicides according to their structure and listed out the acute phytotoxicity endpoints. The potential mechanism for the enantioselective toxicity was concluded into 5 main points.


RESULTS
The enantiomer-specific toxicity on plant growth and flowers are limited on phenoxyalkanoic acid herbicide, aryloxyphenoxypropanoic acid, imidazolinone herbicide, and acetamide pesticide. Data available on the potential mechanism explanation of enantioselective phytotoxicity has been concerned on the genetic transcription, oxidative stress, and photosynthesis disruption, etc. A comparison between the two enantiomers' enantioselective effects identified an organ-specific and species-specific phenomenon for several herbicides. Moreover, a more herbicidal activity enantiomer is also displayed the more toxicity than its antipode.


CONCLUSIONS
The review elucidated a paucity of information on the enantioselective effect research on various types of plants at the different life stages. It appealed us to conduct a more holistic approach to balance the benefit between herbicidal activity and phytotoxicity when try to develop an enantio-pure herbicide.
Cui
C
Wang
Dezhao
D
Lu
Jinhuan
J
Yang
Yingling
Y
Xu
Chenxue
C
Gong
College of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, China.
Zhuoyu
Z
Li
D000818:Animals; D001673:Biodegradation, Environmental; D001711:Biotransformation; D002384:Catalysis; D055772:Green Chemistry Technology; D015386:Hazardous Substances / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D006801:Humans; D010084:Oxidation-Reduction; D010788:Photosynthesis; D018521:Plant Physiological Phenomena
D015386:Hazardous Substances; D006540:Herbicides