Dormancy cycling is accompanied by changes in ABA sensitivity in Polygonum aviculare seeds

Abstract Polygonum aviculare seeds show high levels of primary dormancy (PD). Low winter temperatures alleviate dormancy and high spring temperatures induce seeds into secondary dormancy (SD), naturally establishing stable seedbanks cycling through years. The objective of this work was to elucidate the mechanism(s) involved in PD expression and release, and in SD induction in these seeds, and the extent to which abscisic acid (ABA) and gibberellins (GAs) are part of these mechanisms. Quantification of endogenous ABA both prior to and during incubation, and sensitivity to ABA and GAs, were assessed in seeds with contrasting dormancy. Expression analysis was performed for candidate genes involved in hormone metabolism and signaling. It was found that endogenous ABA content does not explain either dormancy release or dormancy induction; moreover, it does not seem to play a role in dormancy maintenance. However, dormancy modifications were commonly accompanied by changes in ABA sensitivity. Concomitantly, induction into SD, but not PD, was characterized by a increased PaABI-5 and PaPYL transcription, and a rise in GA sensitivity as a possible counterbalance effect. These results suggest that dormancy cycling in this species is related to changes in embryo sensitivity to ABA; however, this sensitivity appears to be controlled by different molecular mechanisms in primary and secondary dormant seeds.

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Reduced embryo sensitivity to abscisic acid in a sprouting-susceptible sorghum (Sorghum bicolor) variety is associated with altered ABA signalling

Seed Science Research ◽

10.1017/s0960258507708115 ◽

2007 ◽

Vol 17 (2) ◽

pp. 81-90 ◽

Cited By ~ 9

Author(s):

Nicolás Gualano ◽

Fernando Carrari ◽

María Verónica Rodríguez ◽

Laura Pérez-Flores ◽

Rodolfo Sánchez ◽

...

Keyword(s):

Abscisic Acid ◽

Sorghum Bicolor ◽

Developmental Stages ◽

Signal Transduction Pathway ◽

Transduction Pathway ◽

Aba Signal Transduction ◽

Aba Sensitivity ◽

Two Stages ◽

Aba Content ◽

Endogenous Aba

AbstractIn the work reported in this paper, we attempted to elucidate the nature of the different abscisic acid (ABA) sensitivities presented by developing embryos from sorghum [Sorghum bicolor (L.) Moench] lines with contrasting pre-harvest sprouting (PHS) behaviour (Redland B2, susceptible; IS 9530, resistant). We explored two different hypotheses for a possible mechanism: (1) a different functionality of the ABA signalling pathway, and (2) a different rate of ABA degradation/conjugation in the apoplast of embryos from these genotypes. To assess the first possibility, we used an ABA-responsive gene (Rab17) as a reporter of changes in endogenous ABA content, which were artificially induced in embryos from both genotypes by means of fluridone application immediately after anthesis, to reduce ABA content, and embryo incubation in the presence of ABA. A defect in ABA signalling should be seen as a level of Rab17 expression that is independent of endogenous ABA content. For testing the second possibility at two stages of development, embryos from both lines were isolated and incubated in water for different periods. ABA concentrations in embryos and the incubation media were quantified through radioimmunoassay. In contrast to our findings for the resistant IS 9530 line, Rab17 expression did not respond to changes in ABA levels in sensitive Redland B2 embryos. The ABA degradation/conjugation rates in embryos and incubation media did not show clear differences between sorghum lines for any of the developmental stages analysed. These results suggest that a disruption in the ABA signal transduction pathway in Redland B2 underlies the low ABA sensitivity shown by embryos from this line.

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Global warming leads to more uniform spring phenology across elevations

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1717342115 ◽

2017 ◽

Vol 115 (5) ◽

pp. 1004-1008 ◽

Cited By ~ 78

Author(s):

Yann Vitasse ◽

Constant Signarbieux ◽

Yongshuo H. Fu

Keyword(s):

Global Warming ◽

Mountain Forest ◽

European Alps ◽

Spring Phenology ◽

Winter Temperatures ◽

Spring Temperatures ◽

Plant Animal Interactions ◽

Tree Leaf ◽

And Function ◽

Phenological Shift

One hundred years ago, Andrew D. Hopkins estimated the progressive delay in tree leaf-out with increasing latitude, longitude, and elevation, referred to as “Hopkins’ bioclimatic law.” What if global warming is altering this well-known law? Here, based on ∼20,000 observations of the leaf-out date of four common temperate tree species located in 128 sites at various elevations in the European Alps, we found that the elevation-induced phenological shift (EPS) has significantly declined from 34 d⋅1,000 m−1 conforming to Hopkins’ bioclimatic law in 1960, to 22 d⋅1,000 m−1 in 2016, i.e., −35%. The stronger phenological advance at higher elevations, responsible for the reduction in EPS, is most likely to be connected to stronger warming during late spring as well as to warmer winter temperatures. Indeed, under similar spring temperatures, we found that the EPS was substantially reduced in years when the previous winter was warmer. Our results provide empirical evidence for a declining EPS over the last six decades. Future climate warming may further reduce the EPS with consequences for the structure and function of mountain forest ecosystems, in particular through changes in plant–animal interactions, but the actual impact of such ongoing change is today largely unknown.

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Differential Expression of Genes Related to the Formation of Giant Leaves in Triploid Poplar

Forests ◽

10.3390/f10100920 ◽

2019 ◽

Vol 10 (10) ◽

pp. 920 ◽

Cited By ~ 1

Author(s):

Kang Du ◽

Qiang Han ◽

Ying Zhang ◽

Xiangyang Kang

Keyword(s):

Transcription Factors ◽

Molecular Mechanisms ◽

Leaf Growth ◽

Growth Hormones ◽

Endogenous Hormones ◽

Rna Seq ◽

Hormone Metabolism ◽

Expression Of Genes ◽

Genes Expression ◽

Differential Expression Of Genes

Plant polyploids tend to have large leaves, but their formation mechanism has not yet been well explained. Therefore, daily transcriptomic differences between triploids and diploids from a synthetic Populus sect. Tacamahaca three times a day (i.e., 04:00, 09:00, and 21:00) were investigated using high-throughput RNA-seq analysis. In this study, we identified several transcription factors associated with giant leaves. The combined effects included the high expression of several transcription factors (WRKY, MYB, etc.) and hormone-related genes (e.g., activates auxin, cytokine, and brassinosteroid synthesis-related genes) that accelerate the synthesis and accumulation of endogenous hormones. High levels of growth hormones were maintained by reducing the genes’ expression of hormone metabolism and degradation. The coordination of hormones accumulated sufficient materials and energy for leaf growth and development. Thereby, cell division and growth were accelerated which enhanced the photosynthesis of leaves, and the increased accumulation of photosynthetic products led to giant triploid leaves. This study lays the foundation for revealing the molecular mechanisms in the formation of giant leaves in polyploids.

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Molybdenum deficiency in wheat results in lower dormancy levels via reduced ABA

Seed Science Research ◽

10.1017/s0960258500002373 ◽

1994 ◽

Vol 4 (3) ◽

pp. 329-333 ◽

Cited By ~ 9

Author(s):

A. T. Modi ◽

A. L. P. Cairns

Keyword(s):

Abscisic Acid ◽

Field Experiment ◽

Nutrient Solution ◽

Foliar Application ◽

Flag Leaf ◽

Foliar Spray ◽

Leaf Stage ◽

Enhanced Sensitivity ◽

Aba Content ◽

Endogenous Aba

AbstractWheat which was grown in acid-washed sand and irrigated with a molybdenum-free nutrient solution was treated with various concentrations of molybdenum (Mo) as a foliar spray at the flag leaf stage. At maturity, dormancy levels and abscisic acid (ABA) content of the seed were determined. Seed dormancy and ABA content increased with increasing rates of Mo application. In a field experiment, wheat (cv. SST 66) was treated with 100 ppm Mo by foliar application at the flag leaf stage. Embryos were tested for sensitivity to exogenously applied ABA. Embryos from Mo-treated plants showed enhanced sensitivity to ABA-induced inhibition of germination. The Mo application also resulted in significantly higher levels of endogenous ABA and Mo in the seeds. It is postulated that Mo deficiency leads to a lack of dormancy in wheat via reduced synthesis of ABA.

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

Seed Science Research ◽

10.1079/ssr2002117 ◽

2002 ◽

Vol 12 (4) ◽

pp. 239-252 ◽

Cited By ~ 31

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.

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Functional Identification of 9-cis-epoxycarotenoid Dioxygenase Genes in Double Dormant Plant-herbaceous Peony

10.21203/rs.3.rs-1176350/v1 ◽

2021 ◽

Author(s):

Riwen Fei ◽

Siyang Duan ◽

Jiayuan Ge ◽

Tianyi Sun ◽

Xiaomei Sun

Keyword(s):

Seed Dormancy ◽

Dormancy Release ◽

Transcriptome Data ◽

Functional Identification ◽

Internal Factors ◽

Herbaceous Peony ◽

Aba Metabolism ◽

Complex Process ◽

Aba Content ◽

Endogenous Aba

Abstract Seed dormancy and germination is a complex process, which is affected by external environmental conditions and internal factors independently or mutually. Phytohormones play an important regulatory role in this process. ABA was the main phytohormone affecting herbaceous peony seed dormancy release. However, the mechanism of ABA in the dormancy release of herbaceous peony needs to be further explored. Here, transcriptome data was screened from the perspective of ABA metabolism, and significantly differentially expressed PlNCED1 and PlNCED2 were obtained. We found that their expression trends were positively correlated with ABA content. Among them, PlNCED2 had a stronger regulatory effect on ABA content and was more sensitive to exogenous ABA. Overexpression and silencing of PlNCEDs in callus could affect the expression of PlCYP707As and the content of endogenous ABA. Through the observation of seed germination of Arabidopsis thaliana (A. thaliana), we found PlNCED1 and PlNCED2 promoted seed dormancy, and the promotion effect of PlNCED2 was more obvious. In general, PlNCED1 and PlNCED2 participated in the dormancy release of herbaceous peony seeds by regulating the accumulation of endogenous ABA. Our work can reveal the molecular mechanism and related theories of ABA involved in herbaceous peony seed dormancy release.

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Pollination and CPPU Treatment Increase Endogenous IAA and Decrease Endogenous ABA in Muskmelons during Early Development

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.127.6.908 ◽

2002 ◽

Vol 127 (6) ◽

pp. 908-911 ◽

Cited By ~ 11

Author(s):

Yasuyoshi Hayata ◽

Xin-Xian Li ◽

Yutaka Osajima

Keyword(s):

Early Development ◽

Cucumis Melo ◽

Fruit Set ◽

Parthenocarpic Fruit ◽

Fresh Weight ◽

Endogenous Iaa ◽

Endogenous Plant Hormones ◽

Aba Content ◽

Indole 3 Acetic Acid ◽

Endogenous Aba

An investigation was conducted to determine how pollination and CPPU treatment influence endogenous IAA and ABA content in netted muskmelon [Cucumis melo L. (Reticulatus Group) `Crest Earl's'], and to clarify their roles in fruit set and development in relation to these endogenous plant hormones. CPPU treatment at anthesis significantly increased the fresh weight of ovaries, whether the flowers were pollinated or not, but from 6 days after anthesis (DAA) the growth rate in the nonpollinated + CPPU treatment tended to be lower than the growth rates in the pollination treatment plots. Ovaries of nonpollinated flowers not treated with CPPU failed to grow and turned brown within 4 DAA. IAA content in the placenta of fruit from pollinated flowers increased rapidly from the day of anthesis to 2 DAA and remained at relatively high levels. IAA content in the placenta of parthenocarpic fruit induced to develop by CPPU treatment was lower than that of fruit from pollinated flowers but the pattern was almost the same as that in fruit of pollinated flowers. Conversely, IAA content in the placenta of fruit from nonpollinated flowers not treated with CPPU decreased sharply after anthesis. IAA content in the mesocarp of CPPU-treated fruit, whether or not the flowers were pollinated, increased significantly from the day of anthesis to 2 DAA, then decreased to almost the same level as that of the pollination-only treatment by 10 DAA, while the IAA content of nonpollinated CPPU-treated fruit declined even further. IAA content in the mesocarp of fruit from nonpollinated flowers not treated with CPPU decreased sharply. ABA contents in both the placenta and mesocarp of muskmelon that would set decreased after anthesis while the ABA content of muskmelon that would not set increased rapidly. Results suggest that pollination and CPPU treatment increased endogenous IAA content and decreased endogenous ABA content to promote the set and growth of fruit during early development. Chemical names used: [1-(2-chloro-4-pyridyl)-3-phenylurea] (CPPU); indole-3-acetic acid (IAA); abscisic acid (ABA).

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

BMC Plant Biology ◽

10.1186/s12870-020-02701-z ◽

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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