• Journal of Plant Biology
• /
• 제32권4호
• /
• pp.343-350
• /
• 1989

Calcium promoted ethylene production from mungbean hypocotyl segments incubated in the presence of either auxin or cytokinin (kinetin). Time course studies indicated that the calcium effect on ethylene production had a longer latent period (about 6 h) in combination with kinetin than with auxin. Studies on the effects of agents that are known to interfere with either action or transport (uptake) of calcium on ethylene biosynthesis indicated different patterns between auxin- and kinetin-treated tissues. Auxin-induced ethylene production was inhibited by the calmodulin inhibitor, trifluoperazine (TFP), and this inhibition was overcome by high concentrations of calcium applied, but TFP had no significant effect on kinetin-induced ethylene production regardless of calcium in the medium. The calcium channel blocker, verapamil, inhibited auxin-induced, but had little effect on kinetin-induced, ethylene producton. In vivo activity of "ethylene forming enzyme (EFE)" was found to be substantially promoted by calcium treatment. The enzyme activity was further increased by kinetin when segments were simultaneously treated with calcium, but auxin did not have such an effect.an effect.

• Molecules and Cells
• /
• 제41권12호
• /
• pp.1033-1044
• /
• 2018

As sessile organisms, plants have evolved to adjust their growth and development to environmental changes. It has been well documented that the crosstalk between different plant hormones plays important roles in the coordination of growth and development of the plant. Here, we describe a novel recessive mutant, mildly insensitive to ethylene (mine), which displayed insensitivity to the ethylene precursor, ACC (1-aminocyclopropane-1-carboxylic acid), in the root under the dark-grown conditions. By contrast, mine roots exhibited a normal growth response to exogenous IAA (indole-3-acetic acid). Thus, it appears that the growth responses of mine to ACC and IAA resemble those of weak ethylene insensitive (wei) mutants. To understand the molecular events underlying the crosstalk between ethylene and auxin in the root, we identified the MINE locus and found that the MINE gene encodes the pyridoxine 5′-phosphate (PNP)/pyridoxamine 5′-phosphate (PMP) oxidase, PDX3. Our results revealed that MINE/PDX3 likely plays a role in the conversion of the auxin precursor tryptophan to indole-3-pyruvic acid in the auxin biosynthesis pathway, in which TAA1 (TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1) and its related genes (TRYPTOPHAN AMINOTRANSFERASE RELATED 1 and 2; TAR1 and TAR2) are involved. Considering that TAA1 and TARs belong to a subgroup of PLP (pyridoxal-5′-phosphate)-dependent enzymes, we propose that PLP produced by MINE/PDX3 acts as a cofactor in TAA1/TAR-dependent auxin biosynthesis induced by ethylene, which in turn influences the crosstalk between ethylene and auxin in the Arabidopsis root.

• Journal of Plant Biology
• /
• 제35권4호
• /
• pp.425-429
• /
• 1992

Ranunculus sceleratus 엽병의 세포 신장은 에틸렌에 의하여 촉진되는 것으로 알려져 있다. 오옥신을 처리한 엽병조직 절편에서 spermine은 세포 신장과 에틸렌의 생성을 비슷한 양상으로 억제하였다. Spermine 농도에 대한 오옥신 유도 에틸렌 생성 억제반응은 ACC에 의한 에틸렌 생성의 경우도 유사한 양상을 나타내었으며 이는 폴리아민이 ACC가 에틸렌으로 전환되는 과정을 억제한다는 것을 시사한다. 오옥신 유도 에틸렌 생성은 폴리아민 생합성 억제제인 DFMA아 DFMO에 의하여 각각 현저하게 촉진되었으며 DFMA에 의한 에틸렌 생성의 증가는 spermine을 고농도로 처리하므로써 완전히 소멸되는 결과를 얻었다. 이러한 결과들은 오옥신과 에틸렌에 대한 Ranunculus의 세포성장 반응에서 내생 폴리아민이 조절 역할을 수행한다는 가능성을 입증하는 것이다.

• Journal of Plant Biology
• /
• 제37권4호
• /
• pp.397-402
• /
• 1994

Possible roles of polyamines in the inhibition of cell elongation in Ranunculus petioles were investigated. Exogenously apoplied polyamines greatly inhibited the auxin-induced petiole growth, while treatment of the tissue with $\alpha$-difluoromethylarginine, the inhibitor of putrescine biosynthesis, further enhanced the growth in the presence of IAA. Inhibitory effect of spermine can also be apparent for fusicoccin-induced elongation, but not for growth induced by a low pH. Spermine also suppressed the ethylene-enhanced growth in the presence of auxin. Using computer-based video digitizer system, the inhibitory effects of spermine on petiole growth were kinetically analyzed. Auxin-induced growth was characterized by an initial and transient growth with a highly elevated rate followed by a steady growth with a slightly reduced rate. Spermine treatment was found to shorten the duration of the initial phase of growth, and to reduce the rates of both the initial and steady growth as well. The latent period for auxin induction was not affected by spermine.

• 한국잡초학회지
• /
• 제12권1호
• /
• pp.39-45
• /
• 1992

최근(最近)에 개발(開發)된 수도(水稻) 도복경감제(倒伏輕減劑)를 공시(供試)하여 gibbeellin 길항작용(拮抗作用), auxin 상호작용(相互作用), ethylene 발생(發生) 및 후작물(後作物) 생육(生育)에 마치는 효과(效果)를 검토(檢討)한 바 그 주요결과(主要結果)는 다음과 같다. 1. 수도(水稻) 도복경감제(倒伏輕減劑) (inabenfide, paclobutrazol 및 uniconazole) 처리(處理)가 녹두의 상배축(上胚軸)을 크게 억제(抑制)시켰으나 $GA_3$와의 혼용처리시(混用處理時) $GA_3$ 농도(濃度)가 높을수록 더욱 신장(伸長)되는 길항작용(拮抗作用)을 보였다. 2. 수도(水稻) 도복경감제(倒伏輕減劑) 처리시(處理時) 녹두의 부정근(不定根) 발생(發生)을 현저(顯著)히 증가(增加)시켜 auxin과의 갚은 상호작용(相互作用)이 있는 것으로 추찰(推察)되며, $GA_3$ 농도(濃度)가 높을수록 부정근(不定根)의 발생(發生)이 억제(抑制)되었다. 3. Ethylene 발생(發生)은 수도(水稻) 도복경감제(倒伏輕減劑) 처리(處理)에 依(의)해 단기간(短期間) (5 DAT)에는 증가(增加)하였으나 시간(時間)이 경과(時間)할수록 (10, 30 DAT), 엽량(葉量)이 많을수록 억제(抑制)되었다. 4 후작물(後作物)에 미치는 수도(水稻) 도복경작제(倒伏耕作劑)의 처리효과(處理效果)는 화본과(禾本科)인 보리에서는 별(別)로 큰 영향(影響)이 없었으나 광엽(廣葉)인 토마토에서는 초장(草長)이 크게 억제(抑制)되었다. Inabenfide는 처리후(處理後) 30 일(日)에 회복(回復)이 되었으나 paclobutrazol과 uniconazole은 그 억제(抑制)가 매우 컸다.

• 식물조직배양학회지
• /
• 제22권6호
• /
• pp.345-350
• /
• 1995

완두 돌연변이체 ageotropum 뿌리의 굴중성 결여에 대하여 조사하였다. 정상 완두의 뿌리에서 에틸렌은 굴중성 반응을 억제하였다. 돌연변이체에서는 에틸렌이나 에틸렌 생합성 억제제 또는 작용 억제제 모두 뿌리의 굴중성 반응 결여를 회복시키지 못하였다. 옥신을 비대칭으로 처리한 뿌리에서 굴성반응이 일어나는 것으로 보아 옥신의 작용은 정상적으로 일어나는 것으로 판단되었다. 내생적 또는 옥신유도에 의한 에틸렌 생성은 정상 완두나 돌연변이체에서 크게 차이가 없었다. 그러나 정상 완두에서와는 달리 돌연변이체의 뿌리에서는 굴중성 반응의 작동체계인 옥신작용의 결함이 아니고 중력의 인식 또는 전달과정에 결함이 있다는 결론을 얻었다.

• The Plant Pathology Journal
• /
• 제40권2호
• /
• pp.99-105
• /
• 2024

Land plants produce glucose (C₆H₁₂O₂) through photosynthesis by utilizing carbon dioxide (CO₂), water (H₂O), and light energy. Glucose can be stored in various polysaccharide forms for later use (e.g., sucrose in fruit, amylose in plastids), used to create cellulose, the primary structural component of cell walls, and immediately metabolized to generate cellular energy, adenosine triphosphate, through a series of respiratory pathways including glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Additionally, plants must metabolize glucose into amino acids, nucleotides, and various plant hormones, which are crucial for regulating many aspects of plant physiology. This review will summarize the biosynthesis of different plant hormones, such as auxin, salicylic acid, gibberellins, cytokinins, ethylene, and abscisic acid, in relation to glucose metabolism.

• Journal of Plant Biology
• /
• 제31권3호
• /
• pp.239-247
• /
• 1988

Spermidine, spermine and IAA promoted an increase in $\beta$-1, 4-endoglucanase activity in hypocotyls of Glycine max. The optimal concentration for the increase of the enzyme activity was 10-6 M for spermidine, 10-8 M for spermine and 10-6 M for IAA. However, IAA had innocuous effect on arginine decarboxylase and ornithine decarboxylase activites, and the content of polyamine. Such cumulative results suggest that the increase in $\beta$-1, 4-endoglucanase activity by IAA is not attributed by the effect on the biosynthesis of polyamine by IAA but spermidine, spermine and IAA induce cell wall loosening and therefore extension growth of cells.

• 생명과학회지
• /
• 제19권8호
• /
• pp.1139-1144
• /
• 2009

옥수수 뿌리에 BL을 처리하면 양성굴중성 반응이 촉진되고, ethylene 생성도 증가한다는 것이 알려져 있다. BL에 의해 유도된 굴중성 반응과 ethylene 생성과의 관계를 조사하였다. ethylene 생성 억제제인 $10^{-4}$ M AVG를 처리하면 ethylene 생성은 90% 이상 억제되었으나, 굴중성 반응은 13% 정도 억제되었다. AVG를 BL과 함께 처리한 뿌리는 ethylene 생성은 약 60% 억제되었으나 굴중성 반응은 대조구 보다 증가하였다. 다른 ethylene 생성 억제제인 cobalt ion을 처리하면 ethylene 생성은 약 10% 정도 억제되었으나 굴중성 반응은 억제되지 않았다. BL과 cobalt ion을 함께 처리한 뿌리는 ethylene 생성이 억제되었으나 굴중성 반응은 증가되었다. 이러한 BL의 효과가 auxin transport와 관계가 있는지 알아보기 위하여 auxin transport inhibitor인 TIBA를 처리하였다. $10^{-5}$ M TIBA와 BL과 TIBA를 함께 처리한 경우(BL+TIBA), ethylene 생성은 각각 96%, 132% 증가하였으나 굴중성 반응은 모두 일어나지 않았다. 또한, BL, TIBA 그리고 IAA를 함께 처리한 뿌리 (BL+TIBA+IAA)는 음성굴중성 반응을 나타냈으나 뿌리 생장은 오히려 증가시켰으며, 이는 수평으로 있는 뿌리에서 IAA가 아랫면으로 transport 되지 못하고 윗면에 축적된 것을 의미한다. 이러한 결과는 BL이 뿌리 내에 존재하는 IAA의 차등분포에 영향을 주어 양성굴중성 반응을 촉진할 가능성을 제시한다.

• Journal of Applied Biological Chemistry
• /
• 제51권3호
• /
• pp.83-87
• /
• 2008

Tension wood, a specialized tissue developed in the upper side of the leaning stem and drooping branches of angiosperm, is an attractive experimental system attractive for exploring the development and the biochemical pathways of the secondary cell wall formation, as well as the control mechanism of the carbon flux into lignin, cellulose, and hemicellulose. However, the mechanism underlying the induction and the development of the tension wood is largely unknown. Recently, several researchers suggested the possible roles of the plant growth hormones including auxin, gibberellin, and ethylene mainly based on the expression pattern of the genes in this specialized tissue. In addition, expressed sequence tag of Poplar and Eucalyptus provide global view of the genetic control underlying the tension wood formation. However, the roles of the majority of the identified genes have not yet been clearly elucidated. The present review summarized current knowledge on the biosynthesis of tension wood to provide a brief synopsis of the molecular mechanism underlying the development of the tension wood.