The role of abscisic acid in germination of light-sensitive and light-insensitive lettuce seeds

1999 ◽  
Vol 9 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Nurit Roth-Bejerano ◽  
Norbert J.A. Sedee ◽  
Rene M. van der Meulen ◽  
Mei Wang
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Inhibitory Processes ◽  
Exogenous Aba ◽  
Lettuce Seeds ◽  
Endogenous Level ◽  
Aba Content ◽  
Aba Biosynthesis ◽  
Light Break

AbstractThe role of abscisic acid (ABA) in seed germination of two cultivars of lettuce (Lactuca sativa L.; light-sensitive Ritsa and light-insensitive Strada) was investigated. The inhibition of Ritsa seed germination by exogenous ABA was higher than that of Strada seeds, the extent of inhibition of both cultivars being reduced by a short light break. At 25°C the sensitivity of both cultivars to exogenous ABA was higher than at 15°C. The endogenous level of ABA was similar in dry seeds of both cultivars, increasing temporarily in Ritsa seeds during the first 4 h of imbibition in darkness but not in Strada seeds, nor in Ritsa seeds exposed to a short light break. The transitory increase of ABA content in Ritsa seeds imbibed in darkness was accompanied by increased expression of the gene responsive to ABA (Rab) under these conditions. Zorial (Norflurazone), an ABA-biosynthesis inhibitor, decreased ABA content and allowed dark germination of the light-requiring Ritsa seeds. A short light break induced germination of Ritsa seeds when applied at 24 and 48 h after imbibition onset, i.e. after the transitory increase of ABA. GA3, on the other hand was effective when applied at the beginning of imbibition. It seems that light induces germination of the photoblastic Ritsa seeds by both inhibiting ABA synthesis and decreasing seed sensitivity to ABA and inhibitory processes induced by it.

The Effects of Abscisic Acid on Photosynthesis in Tomato Under Sub-High Temperature and High Light Stress

2016 ◽  
Vol 13 (10) ◽  
pp. 7189-7198
Author(s):  
Shuang Gang ◽  
Yufeng Liu ◽  
Tao Lu ◽  
Mingfang Qi ◽  
Xiaoxi Guan ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
High Temperature ◽  
Light Stress ◽  
High Light ◽  
Exogenous Aba ◽  
Photosystems I And Ii ◽  
Genes Expression ◽  
Irreversible Reduction ◽  
Aba Biosynthesis

The present study investigated the role of abscisic acid (ABA) application in photosynthesis, photosystems I and II (PSI and PSII), antioxidant system and ABA-related genes expression under sub-high temperature and high light (STHL) stress. STHL treatment led to an irreversible reduction in the photosynthetic rate (Pn), damaged PSII firstly at three hours, and then inhibited RuBPCase activity at seven hours, at last injured PSI after eleven hours. During 11 hours STHL stress, exogenous ABA can alleviate the degree of Pn decreasing, improve the activity of RuBPCase, protect PSII to photoinhibition, and promote the ability of reactive oxygen removal. When severe stress occured, exogenous ABA has certain effect, but can not ease photoinhibition and photodamage. In addition, exogenous ABA effected significantly on genes of upstream regulatory ABA biosynthesis key enzymes and downstream response MYB transcription factors.

Integrative hormone and transcriptome analysis underline the role of abscisic acid in seed shattering of weedy rice

2021 ◽  
Author(s):  
Hong Lang ◽  
Yuting He ◽  
Fengcheng Li ◽  
Dianrong Ma ◽  
Jian Sun
Keyword(s):  
Abscisic Acid ◽  
Critical Role ◽  
Weedy Rice ◽  
Seed Shattering ◽  
High Degree ◽  
Aba Content ◽  
Potential Signal ◽  
Aba Biosynthesis ◽  
Indole 3 Acetic Acid

AbstractWeedy rice is one of the most severe weeds in paddy fields, characterized by its high degree of seed shattering. Abscisic acid (ABA) serves as an abscission-accelerating signal and plays a critical role during abscission. However, mechanisms that link ABA and seed shattering remain elusive. In this study, WR04-6 (shattering) and SN9816 (non-shattering) were used to investigate the expression levels of genes involved in ABA biosynthesis and to determine the levels of ABA in tissues collected from the abscission zone (AZ) and the spikelet. ABA content in WR04-6, particularly in AZ, was significantly higher than in SN9816, significantly increasing prior to abscission. RNA-Sequencing and further expression analyses showed that the expression of OsNCED, the key gene involved in ABA biosynthesis, coincided with the increase of ABA content in the AZ and significantly increased during the seed shattering process. Additionally, the expression analysis of genes related to biosynthesis and metabolism of indole-3-acetic acid, gibberellin acid, and ethylene showed the greatest fold-change. Phytohormone levels associated with ABA co-expression-prediction revealed a potential signal transduction network among plant hormones involved in the regulation of seed abscission. Taken together, data presented in this study suggest that ABA contributes to seed shattering and transiently cooperates with other hormones, triggering a hormone imbalance that leads to the downstream activation of the AZ.

scholarly journals Integrative hormone and transcriptome analyses underline the role of abscisic acid in seed shattering of weedy rice

2020 ◽  
Author(s):  
Hong Lang ◽  
Yuting He ◽  
Jian Sun ◽  
Fengcheng Li ◽  
Dianrong Ma
Keyword(s):  
Abscisic Acid ◽  
Rice Variety ◽  
Critical Role ◽  
Weedy Rice ◽  
Seed Shattering ◽  
Expression Of Genes ◽  
Aba Content ◽  
Potential Signal ◽  
Aba Biosynthesis

Abstract Abstract Backgrounds: Weedy rice is one of the most severe weeds in paddy fields, strongly characterized by its high seed shattering level. Abscisic acid (ABA) serves as an abscission-accelerating signal and plays a critical role during abscission. However, mechanisms that link ABA and seed shattering remain elusive. In this study, we compared WR04-6 a shattering, and SN9816 non-shattering rice variety for genetic expression and ABA levels in the abscission zone (AZ) and the spikelet. Results : ABA content in WR04-6, particularly in AZ, was significantly higher than that in SN9816, and it increased remarkably prior to abscission. Transcriptomic analysis and qRT-PCR showed that the expression of NCED , the key gene in ABA biosynthesis, coincided with increased ABA content in AZ and increased significantly during the seed shattering process. Additionally, the expression of genes related biosynthesis and metabolism of IAA, GA, and ETH showed the greatest fold change. Phytohormone levels associated with ABA co-expression-prediction revealed a potential signal transduction network among plant hormones involved in regulating seed abscission. Conclusions: Altogether, our data strongly indicated that ABA contributes to seed shattering and appears to transiently cooperate with other hormones, triggering a hormone imbalance that leads to the downstream activation of AZ

scholarly journals Transcriptome Reveals Roles of Lignin-Modifying Enzymes and Abscisic Acid in the Symbiosis of Mycena and Gastrodia elata

2021 ◽  
Vol 22 (12) ◽  
pp. 6557
Author(s):  
Li-Ying Ren ◽  
Heng Zhao ◽  
Xiao-Ling Liu ◽  
Tong-Kai Zong ◽  
Min Qiao ◽  
...  
Keyword(s):  
Biological Activity ◽  
Abscisic Acid ◽  
Lignin Degradation ◽  
Molecular Mechanisms ◽  
Receptor Protein ◽  
Gastrodia Elata ◽  
Upregulated Genes ◽  
Aba Biosynthesis ◽  
Seed Coats

Gastrodia elata is a well-known medicinal and heterotrophic orchid. Its germination, limited by the impermeability of seed coat lignin and inhibition by abscisic acid (ABA), is triggered by symbiosis with fungi such as Mycena spp. However, the molecular mechanisms of lignin degradation by Mycena and ABA biosynthesis and signaling in G. elata remain unclear. In order to gain insights into these two processes, this study analyzed the transcriptomes of these organisms during their dynamic symbiosis. Among the 25 lignin-modifying enzyme genes in Mycena, two ligninolytic class II peroxidases and two laccases were significantly upregulated, most likely enabling Mycena hyphae to break through the lignin seed coats of G. elata. Genes related to reduced virulence and loss of pathogenicity in Mycena accounted for more than half of annotated genes, presumably contributing to symbiosis. After coculture, upregulated genes outnumbered downregulated genes in G. elata seeds, suggesting slightly increased biological activity, while Mycena hyphae had fewer upregulated than downregulated genes, indicating decreased biological activity. ABA biosynthesis in G. elata was reduced by the downregulated expression of 9-cis-epoxycarotenoid dioxygenase (NCED-2), and ABA signaling was blocked by the downregulated expression of a receptor protein (PYL12-like). This is the first report to describe the role of NCED-2 and PYL12-like in breaking G. elata seed dormancy by reducing the synthesis and blocking the signaling of the germination inhibitor ABA. This study provides a theoretical basis for screening germination fungi to identify effective symbionts and for reducing ABA inhibition of G. elata seed germination.

Vegetation-derived abscisic acid and four terpenes enforce dormancy in seeds of the post-fire annual,Nicotiana attenuata

2002 ◽  
Vol 12 (4) ◽  
pp. 239-252 ◽  
Author(s):  
Bernd Krock ◽  
Sybille Schmidt ◽  
Christian Hertweck ◽  
Ian T. Baldwin
Keyword(s):  
Abscisic Acid ◽  
Environmental Control ◽  
Wood Smoke ◽  
Nicotiana Attenuata ◽  
Germination Inhibitors ◽  
Physiological Basis ◽  
Fire Environment ◽  
Aba Content ◽  
Aba Biosynthesis ◽  
Endogenous Aba

AbstractThe native tobacco,Nicotiana attenuata, synchronizes its germination with the immediate post-fire environment with a combination of germination stimulants found in wood smoke and inhibitors from the unburned litter of the dominant vegetation. The inhibitors override the stimulants and prevent seeds from germinating maladaptively in unburned habitats adjacent to burns. To understand the physiological basis of this environmental control of germination, we tested several previously isolated signals, phytohormones and their respective biosynthesis inhibitors. The germination inhibitors methyl jasmonate (MeJA, a constituent of sagebrush litter), bornane-2,5-dione (BD, a constituent of juniper litter extract, JLE) and JLE did not alter abscisic acid (ABA) content of imbibed seeds. Treatment with the ABA biosynthesis inhibitor, fluridone, inhibited the dormancy-inducing effects of BD, JLE and MeJA, but surprisingly did not affect endogenous ABA levels in treated seeds. However, ABA leached from litter of the species, which dominate the plant community before fires, plays an important role in germination control. We conclude thatN. attenuataseeds, which can lie dormant in the soil for 150 years between fires, time their germination with the post-fire environment by responding to smoke, ABA and four terpenes (BD, 1,8-cineole, β-thujaplicin and camphor) leaching from the litter of the dominant vegetation.

ABA-dependent sucrose regulation of antioxidant metabolism in wheat cultivars varying in ABA-sensitivity

Biologia ◽  
2015 ◽  
Vol 70 (2) ◽  
Author(s):  
Sandeep Kaur ◽  
Anil Kumar Gupta ◽  
Vikramjit Kaur Zhawar
Keyword(s):  
Antioxidant Enzymes ◽  
Abscisic Acid ◽  
Seed Germination ◽  
Culture Medium ◽  
Sodium Tungstate ◽  
Wheat Cultivars ◽  
Antioxidant Metabolism ◽  
Aba Sensitivity ◽  
Aba Biosynthesis

AbstractEffect of sucrose and its abscisic acid (ABA) dependence was studied for seed germination, growth and antioxidant related parameters in two wheat cultivars PBW343 (ABA-lesser sensitive) and C306 (ABA-higher sensitive) by using sucrose (Suc) with or without sodium tungstate (inhibitor for ABA biosynthesis) in culture medium. Exogenous Suc (at 1.5% and 3%) inhibited germination in both cultivars where ABA-dependency for such inhibitions was seen only under 3% sucrose in PBW343 and 1.5% sucrose in C306. Exogenous Suc at 1.5% stimulated growth, which was ABA-dependent in both cultivars. Exogenous Suc at 3% inhibited growth in both cultivars but such inhibitions were ABA-dependent only in PBW343. Suc supply (3%) decreased antioxidant enzymes and H

scholarly journals The Role of Abscisic Acid in Heat Stress-induced Secondary Dormancy in Apple Seeds

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 175-177 ◽  
Author(s):  
Jocelyn A. Ozga ◽  
F.G. Dennis
Keyword(s):  
Abscisic Acid ◽  
Heat Stress ◽  
Germination Capacity ◽  
Embryonic Axes ◽  
Secondary Dormancy ◽  
Golden Delicious ◽  
Aba Content ◽  
Seed Coats ◽  
Apple Seeds

Exposure of stratified apple (Malus domestics Borkh. cv. Golden Delicious) seeds to 30C induces secondary dormancy. To determine if an increase in abscisic acid (ABA) content was associated with the loss in germination capacity, stratified seeds (3,- 6, or 9 weeks at 5C) were held at 30C for 0, 3, or 6 days. Stratification at 5C either had no effect or increased ABA content in embryonic axes, cotyledons, and seed coats. Exposure to 30C after stratification either did not affect or decreased ABA content of embryonic axes and seed coats; in contrast, cotyledonary ABA was increased. Seed coats, cotyledons, and embryonic axes stratified for 3, 6, or 9 weeks at 20C contained the same or higher levels of ABA in comparison with nonstratified seeds or seeds stratified at SC. Changes in ABA levels were not consistently correlated with changes in germination capacity during stratification or after exposure to 30C. These data suggest that changes in ABA are not related to changes in dormancy. Chemical names used: abscisic acid (ABA); butylated hydroxy-toluene (BHT); n-(trichloromethyl) thio-4-cyclohexene-1,2-dicarboximide(Captan).

scholarly journals Proanthocyanidins in seed coat tegmen and endospermic cap inhibit seed germination in Sapium sebiferum

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4690 ◽  
Author(s):  
Faheem Afzal Shah ◽  
Jun Ni ◽  
Jing Chen ◽  
Qiaojian Wang ◽  
Wenbo Liu ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
Nordihydroguaiaretic Acid ◽  
Potassium Nitrate ◽  
Sapium Sebiferum ◽  
Exogenous Application ◽  
Catabolic Genes ◽  
Long Time ◽  
Aba Biosynthesis

Sapium sebiferum, an ornamental and bio-energetic plant, is propagated by seed. Its seed coat contains germination inhibitors and takes a long time to stratify for germination. In this study, we discovered that the S. sebiferum seed coat (especially the tegmen) and endospermic cap (ESC) contained high levels of proanthocyanidins (PAs). Seed coat and ESC removal induced seed germination, whereas exogenous application with seed coat extract (SCE) or PAs significantly inhibited this process, suggesting that PAs in the seed coat played a major role in regulating seed germination in S. sebiferum. We further investigated how SCE affected the expression of the seed-germination-related genes. The results showed that treatment with SCE upregulated the transcription level of the dormancy-related gene, gibberellins (GAs) suppressing genes, abscisic acid (ABA) biosynthesis and signalling genes. SCE decreased the transcript levels of ABA catabolic genes, GAs biosynthesis genes, reactive oxygen species genes and nitrates-signalling genes. Exogenous application of nordihydroguaiaretic acid, gibberellic acid, hydrogen peroxide and potassium nitrate recovered seed germination in seed-coat-extract supplemented medium. In this study, we highlighted the role of PAs, and their interactions with the other germination regulators, in the regulation of seed dormancy in S. sebiferum.

scholarly journals Changes in abscisic acid metabolism in relation to the maturation of grapevine (Vitis vinifera L., cv. Mencía) somatic embryos

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yosvanis Acanda ◽  
Óscar Martínez ◽  
María Jesús Prado ◽  
María Victoria González ◽  
Manuel Rey
Keyword(s):  
Abscisic Acid ◽  
Somatic Embryos ◽  
Expression Profiles ◽  
Semipermeable Membrane ◽  
Precocious Germination ◽  
Exogenous Aba ◽  
Differentiation Medium ◽  
Conversion Rates ◽  
Aba Content ◽  
Endogenous Aba

Abstract Background Somatic embryogenesis in grapevines is a complex process that depends on many physiological and genetic factors. One of its main limitations is the process of precocious germination of the somatic embryos in differentiation medium. This process lowers plant conversion rates from the somatic embryos, and it is probably caused by a low endogenous abscisic acid (ABA) content. Results Precocious germination of the somatic embryos was successfully avoided by culturing grapevine cv. Mencía embryogenic aggregates over a semipermeable membrane extended on top of the differentiation medium. The weekly analysis of the endogenous ABA and ABA-glucosyl ester (ABA-GE) contents in the aggregates showed their rapid accumulation. The expression profiles of 9-cis-epoxycarotenoid dioxygenase (VvNCED1), 8′-hydroxylase (VvHyd2), UDP-glucosyltransferase (VvUGT) and β-glucosidase (VvBG2) genes in grapevine revealed that the occurrence of a first accumulation peak of endogenous ABA in the second week of culture over the semipermeable membrane was mainly dependent on the expression of the VvNCED1 gene. A second increase in the endogenous ABA content was observed in the fourth week of culture. At this point in the culture, our results suggest that of those genes involved in ABA accumulation, one (VvNCED1) was repressed, while another (VvBG2) was activated. Similarly, of those genes related to a reduction in ABA levels, one (VvUGT) was repressed while another (VvHyd2) was activated. The relative expression level of the VvNCED1 gene in embryogenic aggregates cultured under the same conditions and treated with exogenous ABA revealed the significant downregulation of this gene. Conclusions Our results demonstrated the involvement of ABA metabolism in the control of the maturation of grapevine somatic embryos cultured over a semipermeable membrane and two important control points for their endogenous ABA levels. Thus, subtle differences in the expression of the antagonistic genes that control ABA synthesis and degradation could be responsible for the final level of ABA during the maturation of grapevine somatic embryos in vitro. In addition, the treatment of somatic embryos with exogenous ABA suggested the feedback-based control of the expression of the VvNCED1 gene by ABA during the maturation of grapevine somatic embryos.

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