• Journal of Plant Biology
• /
• 제37권4호
• /
• pp.445-452
• /
• 1994

Methyl jasmonate(MeJA)가 녹두(Phaseolus radiatus L.) 하배축과 잎에서 에틸렌 생성에 미치는 영향을 조사하였다. 녹두 하배축 조직에서의 에틸렌 생성은 MeJA의 농도에 비례해서 감소했으며 그 억제 효과는 3시간 이후부터 현저하게 나타났다. 1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase의 활성에 대한 MeJA의 억제 효과 역시 3시간 이후부터 나타났으며 ACC synthase의 활성에는 별 효과가 없었다. $450\;\mu\textrm{M}$ MeJA가 포함된 배지에서 배양시킨 녹두 하배축 조직에서 옥신 유발 에틸렌 생성은 대조구에 비하여 현저히 억제되었는데 이러한 옥신 유발 에틸렌 생성에 대한 MeJA의 억제 기작을 알아보기 위하여 ACC synthase의 활성과 ACC oxidase의 활성을 조사하였다. MeJA는 옥신이 처리된 조직내 ACC양과 ACC synthase 활성 및 ACC oxidase의 활성을 감소시켰다. 따라서 옥신 유발 에틸렌 생성에 대한 MeJA의 억제 효과는 MeJA가 ACC synthase의 활성 뿐만 아니라 ACC oxidase의 활성을 감소시킴으로써 나타난다고 볼 수 있다. 하배축과는 반대로 $4.5\;\mu\textrm{M}$로 처리한 잎 조직에서의 에틸렌 생성은 대조구에 비해 약 50% 촉진되었으며 옥신에 의해 유발된 에틸렌 생성량은 MeJA에 의해 증가되었다. 잎에서의 MeJA에 의한 에틸렌의 합성 증가는 ACC oxidase의 활성 증가에 기인하였으며 ACC synthase의 효소활성은 변화가 없어TEk. 따라서 MeJA는 녹두의 서로 다른 조직에서 에틸렌 합성에 대해 서로 상반된 효과를 나타내었다.

• Journal of Plant Biology
• /
• 제38권3호
• /
• pp.235-242
• /
• 1995

Effects of methyl jasmonate (MeJA) on ethylene production in tomato(Lycopersicon esculentum Mill.) hypocotyl segments and fruits were studied. Ethylene production in tomato hypocotyl segments was inhibited by the increasing concentratons of MeJA, and 450 $\mu$M of MeJA showed 50% inhibitory effect. Time course data indicate that this inhibitory effect of MeJA appeared after 3 h of incubation period and continued until 24 h. Inhibition of ethylene producton by MeJA was due to the decrease in 1-aminocyclopropane-1-carboxylic acid(ACC) synthase activity. However, MeJA treatment had no effect on ACC oxidase activity and the accumulaton of ACC oxidase mRNAs. MeJA also inhibited auxin-induced ethylene production by decreasing in ACC synthase activity. In contrast, MeJA stimulated ethylene production in tomato fruits. When 30 $\mu$L/mL MeJA was treated in a gaseous state, ethylene production doubled and this stimulating effect continued until 4 days. To investigate the mechanisms of MeJA on ethylene production, ACC synthase and ACC oxidase activities were examined after MeJA treatment. MeJA increased the activities of both ACC synthase and ACC oxidase, and induced ACC oxidase mRNA accumulation. These data suggest that MeJA plays distinct roles in the ethylene production in different tomato tissues. It is possible that MeJA affects differently the mechanisms of signal transuction leading to the ethylene biosynthesis.

• Journal of Plant Biotechnology
• /
• 제2권2호
• /
• pp.83-87
• /
• 2000

Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is induced by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to expression of the cysteine proteinase (CP) gene. Until recently, it has been believed that these two phenomena, autocatalytic ethylene production and wilting, are regulated in concert in senescing carnation petals, since the two phenomena occurred closely in parallel. Our studies with petals of a transgenic carnation harboring a sense ACC oxidase transgene and petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl) semicarbazide showed that the expression of ACC synthase and ACC oxidase genes and that of CP are regulated differently in carnation psanetals. Interestingly, in the petals of transgenic carnation, the transcript for CP was accumulated but the transcripts for ACC synthase and ACC oxidase were not accumulated in response to exogenous ethylene. Based on these results, we hypothesized that two ethylene signaling pathways, one leading to the expression of ACC synthase and ACC oxidase genes and the other leading to the expression of CP gene, are functioning in senescing carnation petals.

• Journal of Plant Biology
• /
• 제39권1호
• /
• pp.31-40
• /
• 1996

Arabidopsis thaliana의 에틸렌 관련 돌연변이체인 에틸렌 과다 생성 돌연변이체(eto1-1)와 에틸렌에 대한 반응이 둔감한 돌연변이체(etr1-3과 ein2-1)의 생리·생화학적 특성을 분석하였다. 2∼3주된 Arabidopsis 식물로부터 얻은 성숙한 잎을 재료로 이용하였다. 에틸렌 생성량은 eto1-1은 야생형의 2배, etr1-3은 야생형의 4배, 그리고 ein2-1은 야생형의 4.5배 더 많았다. eto1-1에서의 ACC synthase와 ACC oxidase 활성은 야생형과 비슷하였으나 ACC 함량은 야생형보다 4.5배 더 많았다. ACC-N-malo-nyltransferase의 활성은 eto1-1이 야생형보다 3배 더 높았으며 SAM synthetase의 활성은 야생형보다 1.5배 더 높았다. 이들 결과로부터 eto1-1로의 변형은 SAM에서 ACC로 전환하는 과정 이전에 있음을 추측할 수 있다. etr1-3과 ein2-1에서 ACC synthase의 활성은 야생형보다 높았으나 ACC oxidase의 활성은 야생형보다 낮았다. 그러나 SAM synthetase 활성은 etr1-3에서는 야생형과 비슷하였고 ein2-1에서는 야생형보다 1.7배 높았다. 이것은 etr1-3과 ein2-1이 에틸렌에 대한 반응에 결함이 있기 때문에 그것으로 인하여 자가 조절이 되지 않았기 때문으로 추정된다. etr1-3의 ACC 함량은 야생형보다 2.3배 더 많았으며 ACC N-malonyltransferase의 활성은 야생형보다 3.9배 더 높았다. 그리고 ein2-1의 ACC 함량은 야생형보다 1.7배 더 많았으며 ACC N-malonyltransferase의 활성이 촉진된 것으로 추정된다. In vitro kinase assay를 한 결과 eto1-1과 ein2-1에서 36 kDa 단백질의 인산화를 관찰할 수 있었다.

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
• /
• pp.62.2-62.2
• /
• 2008

• Journal of Plant Biology
• /
• 제33권4호
• /
• pp.309-314
• /
• 1990

Effect of mannose on auxin-induced ethylene production in corn (Zea mays L.) coleoptiles was studied. Auxin induced ethylene production decreased in proportion to mannose concentrations. The inhibitory effect of mannose appeared after 2 h of incubation. Ethylene production was significantly depressed by mannose at high concentration (10-5M-10-4M) of indole acetic acid (IAA), but not at low concentrations (10-8M-10-6M). The inhibition of auxin-induced ethylene production by mannose was specific, since other sugars such as galactose, glucose, sucrose and mannitol did not have an inhibitory effect. In an effort to elucidate mechanisms of mannose the effect on the auxin induced ethylene production, effect of the sugar on ACC synthase activity and ACC induced ethylene production was studied. Mannose failed to inhibit ACC mediated ethylene production, but decreased both the ACC content and ACC synthase activity in the tissue. These results suggest that the inhibitory effect of mannose on auxin induced ethylene production results from suppression of auxin induction of ACC synthase.

• Journal of Photoscience
• /
• 제10권2호
• /
• pp.189-193
• /
• 2003

The effects of light on the regulation of ethylene biosynthesis during development of mung bean seedlings were investigated by monitoring the differential expression of seven 1-aminocyclopropane-l-carboxylate (ACC) synthase and two ACC oxidase genes. Among them, only the expression of VR-ACS1, VR-ACS6, VR-ACS7, VR-ACO1 and VR-AC02 was observable in etiolated mung bean hypocotyls. When the seedlings were de-etiolated for 1 d under a light/dark cycle of 16 h/8 h, the expression of VR-ACS6, VR-ACS7 and VR-ACO2 was controlled negatively by light. The expression of VR-ACS1 showed a tendency to increase until 6 h after a dark-to-light transition and then decreased at 12 h. On the other hand, the expression of VR-ACO1 was mostly constitutive up to 12 h after the dark-to-light transition. The opening of hypocotyl hooks during de-etiolation in the light was stimulated by the inhibition of the action of endogenous ethylene in the presence of 1-MCP. These results suggest that the negative regulation of light on the expression of ACC synthase and ACC oxidase genes eventually results in the inhibition of ethylene production with an acceleration of the opening of apical hooks.

• BMB Reports
• /
• 제38권3호
• /
• pp.320-327
• /
• 2005

Five ripening-related ACC synthase cDNA isoforms were cloned from 80% ripe papaya cv. 'Sinta' by reverse transcription-PCR using gene-specific primers. Clone 2 had the longest transcript and contained all common exons and three alternative exons. Clones 3 and 4 contained common exons and one alternative exon each, while clone 1, the most common transcript, contained only the common exons. Clone 5 could be due to cloning artifacts and might not be a unique cDNA fragment. Thus, there are only four isoforms of ACC synthase mRNA. Southern blot analysis indicates that all five clones came from only one gene existing as a single copy in the 'Sinta' papaya genome. Multiple sequence alignment indicates that the four isoforms arise from a single gene, possibly through alternative splicing mechanisms. All the putative alternative exons were present at the 5'-end of the gene comprising the N-terminal region of the protein. 'Sinta' ACC synthase cDNAs were of the capacs 1 type and are most closely related to a 1.4 kb capacs 1-type DNA(AJ277160) from Eksotika papaya. No capacs 2-type cDNAs were cloned from 'Sinta' by RT-PCR. This is the first report of possible alternative splicing mechanism in ripening-related ACC synthase genes in hybrid papaya, possibly to modulate or fine-tune gene expression relevant to fruit ripening.

• BMB Reports
• /
• 제40권5호
• /
• pp.791-800
• /
• 2007

Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

• 생명과학회지
• /
• 제20권5호
• /
• pp.745-749
• /
• 2010

본 연구는 옥수수 뿌리에서 cytokinin ($N^6$-benzyladenine; BA)과 IAA를 각각 혹은 같이 처리하여 ethylene 생성에 미치는 영향을 알아보았다. 두 호르몬을 외부에서 동시에 처리하면 ethylene 생성은 각각 처리하였을 때 보다 함께 처리하면 상승적으로 증가하였다. 예를 들면, $10^{-4}\;M$ BA와 $10^{-4}\;M$ IAA를 처리하면 ethylene 생성량은 각각 대조구의 87%와 170% 증가되지만 함께 처리하면 대조구의 480%가 증가된다. 이러한 상승적 효과는 에틸렌생성에 관여하는 효소인 ACC synthase의 활성과 유전자 발현 수준에서도 볼 수가 있었다. 그러나 에틸렌 생성에 관여하는 다른 효소인 ACC oxidase의 활성에서는 관찰되지 않았다. 이러한 결과는 cytokinin인 BA와 IAA가 옥수수 뿌리에서 ACC synthase에 영향을 미쳐 ethylene 생성을 상승적으로 촉진시킨다는 사실을 제시한다.