Effects of Three Allelopathic Phenolics on Chlorophyll Accumulation of Rice (Oryza sativa) Seedlings: I. Inhibition of supply-orientation

三種植物相剋酚酸對水稻葉綠素累積之影響：（一）供給面的抑制

楊棋明(Chi-Ming Yang) ； 李瓊妮(Chyoung-Ni Lee) ； 周昌弘(Chang-Hung Chou)

《Botanical Bulletin of Academia Sinica》 43卷4期 (2002/10) Pp. 299-304

https://doi.org/10.7016/BBAS.200210.0299

摘要

本文探討三種植物相剋酚酸o-hydroxyphenyl acetic acid、ferulic acid和p-coumaric acid對水稻葉綠素累積供給面之影響。二週大之水稻白化幼苗水耕栽培於含或不含25、50或100ppm酚酸之十分之一的Kimura培養液中同，並置於生長箱中，其光週期、光強度和相對溼度分別爲12h，300μmol/m^2s and 70%。水稻葉於處理後第1、3、6、12、24和48小時採收，並測其葉綠素及其生合成三比林種前驅物protoporphyrin IX (Proto)、magnesium-protoporphyrin IX (Mg-Proto)和protochlorophyllide (Pchlide)之含量與比林的莫耳百分比。葉綠素和比林的累積隨著酚酸濃度的增加而抑制的更多。當三種酚酸對Mg-Proto莫耳百分比産生的影響型態相似時，它們對Proto和Pchlide的影響型態則有很大不同。結果強烈顯示Mg-chelatase可能是這三種酚酸作用的主要目標，而其抑制強度則是ferulic acid＞p-coumaric acid＞o-hydroxyphenyl acetic acid。我們的結論是葉綠素累積的供給面受到外來酚酸的明顯抑制，故而導致葉綠素的短缺。

關鍵字

植物相剋酚酸 ； 水稻 ； 葉綠素 ； 供給面 ； o-hydroxyphenyl acetic acid ； Ferulic acid ； p-coumaric acid ； 比林

並列摘要

The effects of three allelopathic chemicals, o-hydroxyphenyl acetic, ferulic, and p-coumaric acids, on the chlorophyll (Chl) supply-orientation in the rice leaf (Otyza sativa cul. TN67) were investigated. Two-week-old etiolated seedlings of rice were cultured in growth chamber in one-tenth Kimura’s culture solution, with or without 25, 50 or 100 ppm of the phenolic compounds. The photoperiod, light intensity, and relative humidity were 12 h, 300 µmol/m^2s, and 70%, respectively. Leaves were harvested at 1, 3, 6, 12, 24 and 48 h after treatment with phenolics. The concentrations of Chl and its three biosynthetic porphyrin precursors-i.e. protoporphyrin IX (Proto), Mgprotoporphyrin IX (Mg-Proto), and protochlorophyllide (Pchlide)-were determined, and the mole percent of total porphyrins was calculated. Accumulation of Chi and porphyrin contents were more inhibited as the phenolic concentrations increased. While the mole percent of Mg-Proto affected by the three allelochemical phenolics exhibited the same pattern, those of Proto and Pchlide showed quite different patterns of change in concentration. The data strongly suggest that Mg-chelatase may be the major target of the three phenolics. The order of inhibition strength is ferulic acid＞p-coumaric acid＞o-hydroxyphenyl acetic acid. It is concluded that the supply-orientation of Chi is significantly inhibited by the exogenous phenolics, causing the shortage of Chl.

並列關鍵字

Allelopathic phenolic ； Chlorophyll ； Ferulic acid ； o-hydroxyphenyl acetic acid ； Oryza sativa ； p-coumaric acid porphyrin ； Supply-orientation