Genetic evidence for natural product‐mediated plant–plant allelopathy in rice (<i>Oryza sativa</i>)

Xu, Meimei,Galhano, Rita,Wiemann, Philipp,Bueno, Emilio,Tiernan, Mollie,Wu, William,Chung, Ill‐,Min,Gershenzon, Jonathan,Tudzynski, Bettina,Sesma, Ane,Peters, Reuben J. Blackwell Publishing Ltd 2012 The New phytologist Vol.193 No.3

<P><B>Summary</B></P><P><P>There is controversy as to whether specific natural products play a role in directly mediating antagonistic plant–plant interactions – that is, allelopathy. If proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (<I>Oryza sativa</I>).</P><P>However, while substantiated by the presence of phytotoxic compounds at potentially relevant concentrations, demonstrating a direct role for specific natural products in allelopathy has been difficult because of the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied.</P><P>The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock‐outs of the relevant diterpene synthases (copalyl diphosphate synthase 4 (OsCPS4) and kaurene synthase‐like 4 (OsKSL4)), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (<I>Echinochloa crus‐galli</I>).</P><P>Thus, our results not only provide novel genetic evidence for natural product‐mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant.</P></P>

알팔파 꽃 추출물의 Autotoxicity와 돌피에 대한 Allelopathy

Ill Min Chung,Song Joong Yun 韓國作物學會 1997 Korean journal of crop science Vol.42 No.6

본 실험은 알파파 꽃 추출물로부터 Allelopathy와 Autotoxicity에 관련되는 활성물질을 분리, 동정하기 위하여 실시하였다. 알팔파 꽃 200g을 80% MeOH로 추출하여 CHCl3 층을 silica gel thin layer chromatography (TLC), microcrystalline cellulose thin layer chromatography (MCTLC)와 droplet countercurrent chromatography(DCCC)의 분획을 이용하여 생물검정을 행하고 DCCC의 생물검정에서 가장 억제력을 보였던 분획 5와 6은 HPLC로 활성물질을 동정하였다. HPLC분석 결과 분획 5에서는 ferulic acid, caffeic acid, vanillic acid, rutin, narringin 이, 분획 6에서는 ferulic acid, caffeic acid, vanillic acid, rutin, coumarin이 동정되었다. 이들 동정된 물질을 이용한 알팔파와 돌피에 대한 발아실험에서도 모두 알팔파와 돌피의 발아와 생육에 억제적으로 작용하였으며, 이중 coumarin의 처리가 가장 억제적이었다. 따라서 이들 물질이 알팔파와 돌피의 autotoxicity와 allelopathy에 관련하는 것으로 생각되었다. The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of CHCl3 extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl3 extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.

호주 알레로파시 연구의 두 방향(1988-1993)

길봉섭,Lovett, J. V. 한국생태학회 1997 Journal of Ecology and Environment Vol.20 No.2

Although the number of active workers in Australia is small the range of species associated with allelopathic activity is at least as large as that reported elsewhere in the world. In this paper, work on native and infroduced plants is discussed under the general heading of "conventional allelopathy", thiat is, interactions between plants which are chemically mediated. Work in which compounds associated with allelopathy, in the conventional sense, are biologically active in different contexts is included under "unconventional allelopathy", Examples which involve microorganisms, corals and other marie species, and mammals are discussed.mmals are discussed.

서양금혼초(Hypochaeris radicata L.)의 수용추출물이 사료작물에 미치는 allelopathy 효과

김옥임,박선일,정일민,하상영,Kim Og-Yim,Park Sun-Ill,Jung Ill-Min,Ha Sang-Young 한국생명과학회 2005 생명과학회지 Vol.15 No.6

서양금혼초(Hypochaeris radicata Linne)에 함유되어있는 화학물질이 사료작물의 미치는 allelopathy효과를 구명하기 위하여 본 실험을 실시하였다 서양금혼초에 함유되어 있는 allelochemicals 물질을 HPLC에 의해 성분 분석한 결과 계절적, 부위별로 차이가 있었으나 $\rho$-hydroxybenzoic acid, chlorogenic acid, catechin, caffeic acid, syringic acid, salicylic acid, $\rho$-coumaric acid, ferulic acid, naringin, hesperidin, myricetin, krans-cinnamic acid, quercetin, naringenin 등 14 종류의 phenolic compounds 성분을 확인하였고 caffeic acid, ferulic acid, naringenin 3종류는 공통으로 함유하고 있는 것으로 분석되었다. 5월에는 일, 7월에는 꽃과 뿌리에서 많은 양의 phenolic acids가 함유되어있고 특히 뿌리에 sali-cylic acid $2085.6{\mu}g/g$,와 quercetin $1522.0[\mu}g/g$,로 함량이 높았다. 서양금혼초 수용성 추출액으로 처리한 사료작물의 생장을 조사한 결과 품종에 따라 처리구와 대조구의 값이 같은 경우도 있으나 모든 조사 항목에서 대조구 보다 처리 값이 낮아 사료작물의 생장이 억제 된 것이 확인되었고 처리농도가 높을수록 강한 억제효과를 나타내었다. 수량의 변화를 조사한 결과 사료작물 품종에 따라 차이가 있으나 전체적으로 억제효과를 나타내었으며 처리농도가 높을수록 강한 억제효과를 나타내었다. 이러한 결과 서양금혼초는 사료작물에 대한 allelopathy 효과가 있음을 밝혀냈다. 특히 화본과 사료작물의 경우 italian ryegrass, 콩과 사료작물의 경우는 purple alfalfa가 생장억제효과가 높게 나타났다. This experiment was performed to examine the allelopathy effect of allelochemical substance on the crop plants. According to the experiment of the allelochemical substances in Hypochaeris radicata by HPLC, there are the differences at each part of plants. However, it is ascertained that there are 14 kinds of phenolic compounds ingredients that are $\rho$-hydroxybenzoic acid, chlorogenic acid, catechin, caffeic acid, syringic acid, salicylic acid, $\rho$-coumaric acid, ferulic acid, naringin, hesperidin, myricetin, trans-cinnamic acid, quercetin and naringenin. The chemicals like caffeic acid, ferulic acid, and naringenin are commonly included. The result of the chemical experiment shows that there are the differences at each season and part of plants. The leaves in May and blossoms and roots in July contain lots of phenolic acids. It is very high contents such as salicylic acid 2085.6 ${\mu}g/g$ and quercetin 1522.0 ${\mu}g/g$, especially in roots of plants. The result on the growth of crop plants treated by the aqueous extract of Hypochaeris radicata shows that the value of the control group and the test group are same in some cases. However, because the treat value of test group is towel'than that of control group in all items of the experiment, it is cofirmed that the growth of crop plants was inhibited and that the inhibitory effect was increased as its density of treatment was increased. The result of change in quantity shows that there are the differences at each kind of crop plants, but the inhibitory effect was increased as its concentration of treatment was increase with entire. As results, it is confirmed that H. radicata has the allelopathy effect to the crop plants. Especially the inhibitory effect on growth is high in gramineous crop, italian ryegrass and leguminous crop. purple alfalfa.

Allopathic Effect of Black Locust (Robinia pseudoacacia L.) and Analysis for Its Allelochemicals

Lee, Chul,Park, Ju-Yong,Kim, Jung-Hee,Park, Young-Goo The Korea Forestry Energy Research Society 2003 산림바이오에너지 Vol.22 No.3

아까시나무에 있어서 알레로파시 효과를 분석하기 위해 아까시나무를 포함하여 13개 수 종에 대한 종자발아 시험을 실시하였다. 아까시나무의 뿌리와 잎의 침출액을 실험에 사용하였다. 침출액에 대한 종자 발아실험 결과 수종에 따라 실험결과가 크게 다르게 나타났다. 아까시나무 잎 침출액에서 아까시나무 종자 발아는 30%가 억제되었다. 실험한 수종가운데 무궁화와 오리나무는 뿌리 침출액에서 억제되었으나 누운측백나무는 잎의 침출액에서 발아가 억제되었다. 아까시나무의 잎과 뿌리 침출액을 HPLC분석 한 결과 알레로파시 효과를 가지고 있는 8종류의 authentic phenolic compounds를 찾아냈다. 잎에서는 전체 페놀물질 중 40%를 차지하고 있는 gentisic acid를 뿌리에서는 syringic acid와 vanillicacid를 발견하였다. 전체적으로 볼 때 뿌리에서.보다 잎에서 7배가 많은 phenolic acids가 추출되었다 조사된 8개 phenolic acid 중에서 뿌리에서는 vanillin만이 잎에서는 coumaricacid 만이 발견 되었다. 결과적으로 13수종 중에 3개 수종에서 잎과 뿌리의 침출액에서 종자 발아가 억제되었다. 종자발아 시험결과 아까시나무의 화학물질의 상호작용은 수종에 따라 차이가 많이 있음을 밝혀냈다. 아까시나무의 phenolic compound 총량은 알레로파시 역할에 큰 영향을 미치지 않았으나 이들 물길의 상승효과가 주요한 역할을 하는 것으로 추정 하였다. Allelopathic effects of black locust(Robinia pseudoacacia L.) was evaluated through germination tests using 13 different species including R. pseudoacacia itself. The water extract from leaf or root of R. pseudoacacia was separately tested. Seed germination of several species was inhibited in the presence of leaf or root extract, although the level of germination was in a wide range depending on the species. Seed germination of R. pseudoacacia was suppressed by 30 % in its leaf extract. Among tested tree species, Hibiscus syriacus and Alnus frma showed significantly inhibited germination in the root extracts whereas Thuja orientalis exhibited germination inhibition in the leaf extract. HPLC was carried out to identify allelochemicals in extracts of leaf and root using eight authentic phenolic compounds that are known to be responsible for allelopathy. The major phenolic compounds occupying about 40 % of total phenolic acids were gentisic acid in leaves and vanillic acid and syringic acid in roots. The leaves contained 7 times more phenolic acids than the roots. Among 8 tested phenolic compounds vanillin was detected only in roots and coumaric acid in leaves. Consequently, 3 out of 13 species showed significantly inhibited germination due to leaf or root extract. This germination test indicates that the inhibitory allelopathic effect by R. pseudoacacia is caused by chemical interaction not by nutritional competition and that the allelochermicals of black locust act species-specifically. No specific influence of the total amount of phenolic compounds on the allelopathic inhibitory germination and the synergic effect by each phenolic compound may play a role for the allelopathic effect by R. pseudoacacia.

돼지풀의 페놀화합물 동정 및 이들 화합물이 잡초의 유식물 생장에 미치는 영향

최봉수(Bongsu Choi),송득영(Duk-Young Song),성좌경(Jwa-Kyung Sung),김충국(Chung-Guk Kim),송범헌(Beom-Heon Song),우선희(Sunhee Woo),이철원(Chulwon Lee) 韓國雜草學會 2010 Weed&Turfgrass Science Vol.30 No.4

외래잡초인 돼지풀은 국내 확산이 우려되는 문제잡초로서 allelopathy와 관련성을 평가하기 위하여 돼지풀이 함유하고 있는 phenolic compounds의 시기별 변화와 이들 화합물에 의한 3종 잡초의 발아 및 초기생육을 평가하였다. 식물의 생육을 억제하는 물질로 잘 알려진 cinnamic acid 유도체인 5종의 페놀화합물은 HPLC를 이용하여 정량분석하였고, 4종 (caffeic acid, o-coumaric acid, p-coumaric acid 및 ferulic acid)의 화합물을 동정하였다. 돼지풀에서 검출된 페놀화합물 중 caffeic acid의 농도가 가장 높았으며, o-와 p-coumaric acid는 개화직전 농도가 개화후기보다 3배 정도 높았다. 돼지풀이 함유하고 있는 페놀화합물의 총함량은 개화직전이 1,377㎍로 개화후기의 1,583㎍보다 낮았으나 돼지풀이 생장률에 비해 증가량은 현저히 낮았다. 표준용액을 이용하여 농도별로 조제한 페놀화합물 중 o-와 p-coumaric acid는 바랭이의 발아를 지연시켰으며, caffeic acid는 피의 발아율을 대조구보다 10% 억제시켰다. 또한 발아가 50%에 도달하는 시점을 나타내는 T50는 10-4M 페놀화합물 처리구의 금방동사니와 바랭이에서 촉진되었으며, 10-3M 페놀화합물 처리구의 금방동사니와 피에서 현저히 지연되었다. 다양한 페놀화합물 중에서 o-coumaric acid는 3종의 모든 잡초에서 하배축과 유근의 신장을 현저히 억제시켰으며, 금방동사니의 뿌리 세포 분열을 억제시켰고, 특히 피의 발근을 100% 억제시켰다. Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at 25℃, 10-3 and 10-4 M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, O-coumaric acid, p-coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of O- and p-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination (T50), phenolic compounds at 10-4 M promoted in Cyperus microiria and E. crus-galli but the level of 10-3 M delayed the T50 of those weeds. The O-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.

수수로부터 allelopathy성 물질의 기내선별

유창연 한국자원식물학회 1994 한국자원식물학회지 Vol.7 No.2

These experiments were conducted to determine the effects of Sorghum allelopathic substances on the callus growh of several weeds and crops. 1. When substances extracted from allelopathic Sorghum(Sorghum bicolor L.) were treated on medium, growth of callus of several weeds and crops were in-hibited. The degree of inhibition differed depending on the genotypes, ranging from 50 to 90% com-pared with that of control. 2. The extracts of above 5% Sorghum inhibited the callus growth of Che-nopodium albun L., Commelina communis L., and .Ammaranthus retroflexus L.and showed in-hibition rate of above 70% in callus growth. These results indicate that we could investigate theallelopaihy effect by using in vitro system. 3. The suitable explant for callus induction fromallelopathic plants was immature embryos, the callus induction rate differed depending on the geno-type, growth regulators and concentrations. In general, the addition of 2, 4-D and NAA onto medium increased the rate and amount of callus.

미국자리공 및 겨자무 잎 추출물의 Allelopathy 효과 기내 검정

裵昌烋,盧一燮,姜權圭,高榮珍 韓國作物學會 1997 Korean journal of crop science Vol.42 No.6

미국자리공 및 겨자무의 잎추출물을 이용하여 기내배지상에서 몇가지 작물들과의 allelopathy를 조사한 결과는 다음과 같다. 1. 미국자리공 잎의 methanol 추출물의 농도가 증가함에 따라 공시한 모든 작물의 발아율, 근장, 배축장, 초장, 생체중, 건물중, 유묘의 활력이 급격하게 감소하였다. 2. 미국자리공의 autoallelopathy는 고농도(50u l 및 100u l) 첨가시에 나타나기 시작하였으며, 생체중과 건물중은 농도가 증가함에 따라 현저히 감소하였다. 3. 겨자무 잎의 methanol 추출물은 공시한 모든 작물의 초기생장량을 유제시키는 효과는 보였으나, 미국자리공의 잎추출물의 효과보다는 높았다. 4. 겨자무 뿌리의 methanol 추출물 처리는 밀, 미국자리공의 배축장을 농도 증가에 따라 감소시켰으나, 나머지 작물은 증가시켰다. 또한 초장도 밀, 고추, 미국자리공에서는 추출물의 농도가 증가할수록 감소하였으나 그 외의 작물에서는 약간 증가하였다. 5. 미국자리공의 methanol 추출물로부터 재출물한 4종의 분획물 중 ethyl acetate 분획물이 발아율 및 초기생육을 가장 크게 감소시켰다. 6. Ethyl acetate 분획물은 다른 분획물보다 벼, 보리, 배추의 엽록소 함량을 감소시켰다. 7. Ethyl acetate 분획물 100u l l 첨가시에 배추의 유리 proline의 함량은 31.2배 증가하였으며, 추출물농도가 증가할수록 proline 함량이 증가하였다. Allelopathic effects on some crops(rice, barley, wheat, Chinese cabbage, leaf mustard, onion, welsh onion, tobacco, red pepper) for extracts of Phytolacca americana and Armoracia rusticana were investigated in MS solid medium. Germination percentage, radicle length, hypocotyl length, plant height, fresh weight, dry weight, and seedling vigor were rapidly inhibited by methanol extract from Phytolacca americana according to increase of the concentration in test plants. Autotoxicity of Phytolacca americana began to appear at concentrations greater than 50~mu l methanol extracts per 20ml medium. The fresh weight and dry weight of Phytolacca americana were also decreased by its own methanol extract according to increase of the concentration. Initial amounts of growth of all crops were also inhibited by methanol extracts from Armoracia rusticana, but the inhibitory effects were lowered than those of methanol extracts of Phytolacca americana. Of four fractions, ethyl acetate, petroleum ether, 1stH2O, 2ndH2O , reextracted from methanol extracts of Phytolacca americana, the ethyl acetate fraction showed the highest allelopathic effects on germination percentage and initial amounts of growth. Chlorophyll contents of rice, barley and Chinese cabbage were more inhibited in the ethyl acetate fraction than in the other fractions. Free proline content of Chinese cabbage was increased 31.2 times in the 100~mu l ethyl acetate fraction, and the contents of rice and barley were also increased according to concentration levels in the ethyl acetate fraction.

Evaluation Method of Weed Suppression by Rice Plant

Sang-Bok Lee,Yeon Chung Ku,Ki Young Seong,Duck Young Song,Kyung In Seo,Jin Chul Shin 韓國作物學會 2005 Korean journal of crop science Vol.50 No.2

Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above 3~~4cm from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of 2.5~times2.5cm at rice clipping of seedling 29 days after rice seeding.

Evaluation Method of Weed Suppression by Rice Plant

Lee Sang-Bok,Ku Yeon Chung,Seong Ki Young,Song Duck Young,Seo Kyung In,Shin Jin Chul The Korean Society of Crop Science 2005 Korean journal of crop science Vol.50 No.2

Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above $3\~4cm$ from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of $2.5\times2.5cm$ at rice clipping of seedling 29 days after rice seeding.