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Masumi Yamagishi - One of the best experts on this subject based on the ideXlab platform.
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RNA-seq-based evaluation of bicolor Tepal pigmentation in Asiatic hybrid lilies (Lilium spp.).
BMC genomics, 2016Co-Authors: Kazuma Suzuki, Masumi Yamagishi, Tomohiro Suzuki, Takashi Nakatsuka, Hideo Dohra, Kohei Matsuyama, Hideyuki MatsuuraAbstract:Color patterns in angiosperm flowers are produced by spatially and temporally restricted deposition of pigments. Identifying the mechanisms responsible for restricted pigment deposition is a topic of broad interest. Some dicots species develop bicolor petals, which are often caused by the post-transcriptional gene silencing (PTGS) of chalcone synthase (CHS) genes. An Asiatic hybrid lily (Lilium spp.) cultivar Lollypop develops bicolor Tepals with pigmented tips and white bases. Here, we analyzed the global transcription of pigmented and non-pigmented Tepal parts from Lollypop, to determine the main transcriptomic differences. De novo assembly of RNA-seq data yielded 49,239 contigs (39,426 unigenes), which included a variety of novel transcripts, such as those involved in flavonoid-glycosylation and sequestration and in regulation of anthocyanin biosynthesis. Additionally, 1258 of the unigenes exhibited significantly differential expression between the Tepal parts (false discovery rates 2-fold higher in the pigmented parts. Thus, LhMYB12 should be involved in the transcriptional regulation of the biosynthesis genes in bicolor Tepals. Other factors that potentially suppress or enhance the expression of anthocyanin biosynthesis genes, including a WD40 gene, were identified, and their involvement in bicolor development is discussed. Our results indicate that the bicolor trait of Lollypop Tepals is caused by the transcriptional regulation of anthocyanin biosynthesis genes and that the transcription profile of LhMYB12 provides a clue for elucidating the mechanisms of the trait. The Tepal transcriptome constructed in this study will accelerate investigations of the genetic controls of anthocyanin color patterns, including the bicolor patterns, of Lilium spp.
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Additional file 1: Table S1. of RNA-seq-based evaluation of bicolor Tepal pigmentation in Asiatic hybrid lilies (Lilium spp.)
2016Co-Authors: Kazuma Suzuki, Masumi Yamagishi, Tomohiro Suzuki, Takashi Nakatsuka, Hideo Dohra, Kohei Matsuyama, Hideyuki MatsuuraAbstract:Summary of assembled sequences from the Tepal parts of the Asiatic hybrid lily Lollypop. Table S3. Primers used for quantitative RT-PCR (qRT-PCR) analysis. Figure S1. Phenylpropanoid, anthocyanin, and cinnamic acid derivative biosynthesis pathways in lily Tepals. Enzymes whose genes are up-regulated in upper Tepals (estimated by qRT-PCR) are shown in blue. 3GT, anthocyanidin 3-O-glucosyltransferase; 3RT, anthocyanidin-3-glucoside rhamnosyltransferase; 4CL, 4-coumaroyl: CoA-ligase; 7GT, anthocyanidin-3-rutinoside 7-glucosyltransferase; ANS, anthocyanidin synthase; CHI, chalcone isomerase; CHS, chalcone synthase; C3H, p-coumarate 3-hydroxylase; C4H, cinnamate 4-hydroxylase; DFR, dihydroflavonol 4-reductase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; FLS, flavonol synthase; GST, glutathione S-transferase; HCT, shikimate O-hydroxycinnamoyl transferase; MATE, multidrug and toxic compound extrusion transporter; PAL, phenylalanine ammonia-lyase. Figure S2. HPLC analysis of anthocyanins and CADs in upper Tepals (upper) and Tepal bases (basal) of lily cultivars. A: Absorbance at 525 nm (anthocyanins) of the Tepal extracts in Lollypop, and cyanidin 3-O-glycoside (Cy3G) and cyanidin 3-O-rutinoside (Cy3R) standards. B: Absorbance at 340 nm (CADs) of the Tepal extracts in six cultivars. Figure S3. Alignment of predicted amino acid sequences of isoforms annotated as LhPAL1, LhPAL2, and LhPAL3 (A), and LhCHSa and LhCHSb (B). Letters on black and grey backgrounds indicate identical and similar amino acids, respectively. Asterisks indicate stop codons. Figure S4. Relative expression levels of c30288_g1 (HCT), c10735_g1 (MYB3), c25442_g1 (MYB8), c25442_g2, c24227_g1 (R3-MYB), c24227_g2 (R3-MYB), c18278_g2 (R3-MYB), c36339_g1 (SPL9), and c16635-g1 (RCP1) in upper Tepals and Tepal bases of Lollypop during floral development (St 1–5). ACTIN was used to normalize the expression of target genes. Values and vertical bars indicate the mean ± standard error (n = 3). The same letters above the columns indicate that the values are not statistically significant (p
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Two distinct spontaneous mutations involved in white flower development in Lilium speciosum
Molecular Breeding, 2015Co-Authors: Kazuma Suzuki, Keisuke Tasaki, Masumi YamagishiAbstract:Lilium speciosum is one of the most important wild species used for breeding Oriental hybrid lily cultivars. Typical L. speciosum flowers possess red Tepals and dark red anthers because of anthocyanin accumulation. However, white-flowered L. speciosum with two distinct phenotypes, one with white Tepals and dark red anthers and the other with white Tepals and yellow anthers, also exists. To elucidate the molecular mechanisms underlying white colouration, we isolated two regulatory genes and eight biosynthetic genes responsible for anthocyanin pigmentation in L. speciosum and compared these in red- and white-flowered lines. In the white Tepal line with dark red anthers, we detected an amino acid substitution in the R2 repeat of LsMYB12, the R2R3-MYB that regulates Tepal-specific anthocyanin biosynthesis, which led to reduced anthocyanin biosynthetic gene transcription and no Tepal pigmentation. This LsMYB12 sequence was identical to that of an LhMYB12 in the white-flowered Oriental hybrid lily cultivar ‘Rialto’, indicating that this LsMYB12 sequence is present in lines that have been used for breeding. In addition, a nonsense mutation was detected in the dihydroflavonol 4-reductase (DFR) sequence of the white Tepal line with yellow anthers, which resulted in a lack of anthocyanin accumulation in Tepals and anthers. This mutated DFR has not been used for lily breeding because white Tepal Oriental hybrid lily cultivars usually have dark red anthers. These results suggest that several mechanisms generate white flowers in lilies, and provide a substantial foundation for the production of Oriental hybrid lily cultivars with novel flower colour combinations.
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The novel allele of the LhMYB12 gene is involved in splatter-type spot formation on the flower Tepals of Asiatic hybrid lilies (Lilium spp.).
The New phytologist, 2013Co-Authors: Masumi Yamagishi, Shinya Toda, Keisuke TasakiAbstract:Summary Many angiosperm families develop spatially regulated anthocyanin spots on their flowers. The Asiatic hybrid lily (Lilium spp.) cv ‘Latvia’ develops splatter-type spots on its Tepals. The splatters arise simply from the deposition of anthocyanin pigments in the Tepal epidermis. To determine how splatter development was regulated, we analysed the transcription of anthocyanin biosynthesis genes, and isolated and characterized an R2R3-MYB gene specific to splatter pigmentation. All anthocyanin biosynthesis genes were expressed in splatter-containing regions of Tepals, but not in other regions, indicating that splatter pigmentation is caused by the transcriptional regulation of biosynthesis genes. Previously characterized LhMYB12 regulators were not involved in splatter pigmentation, but, instead, a new allele of the LhMYB12 gene, LhMYB12-Lat, isolated in this study, contributed to splatter development. In ‘Latvia’ and other lily plants expressing splatters, LhMYB12-Lat was preferentially transcribed in the splatter-containing region of Tepals. Progeny segregation analysis showed that LhMYB12-Lat genotype and splatter phenotype were co-segregated among the F1 population, indicating that LhMYB12-Lat determines the presence or absence of splatters. LhMYB12-Lat contributes to splatter development, but not to full-Tepal pigmentation and raised spot pigmentation. As a result of its unique sequences and different transcription profiles, this new allele of LhMYB12 should be a novel R2R3-MYB specifically associating with splatter spot development.
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The transcription factor LhMYB12 determines anthocyanin pigmentation in the Tepals of Asiatic hybrid lilies (Lilium spp.) and regulates pigment quantity
Molecular Breeding, 2011Co-Authors: Masumi Yamagishi, Yusuke Yoshida, M. NakayamaAbstract:A single dominant locus determines anthocyanin biosynthesis in the Tepals of Asiatic hybrid lilies (Lilium spp.); however the gene that determines this trait has not been previously reported. Furthermore, anthocyanin colour hue in Tepals varies between cultivars, but the mechanisms underlying this variation are not known. Here, we show that LhMYB12, which is homologous to petunia An2, determines anthocyanin pigmentation in Tepals and that the level of LhMYB12 transcription affects the quantity of anthocyanin pigments, producing colour hue variation in Tepals. The pink-Tepal cultivars Montreux and Renoir were heterozygous for the LhMYB12 gene. Their F1 population segregated 3:1 for the presence or absence of anthocyanin in Tepals, and LhMYB12 cosegregated perfectly with the presence of anthocyanin, indicating that LhMYB12 determines anthocyanin biosynthesis in Tepals. Among seven cultivars, a single anthocyanin cyanidin 3-O-β-rutinoside was detected in Tepals displaying light pink, pink–red, dark red, or chocolate brown hues. However, concentrations differed according to the following order of colour hue: light pink < pink–red < dark red < chocolate brown, suggesting that colour hue variation in Tepals is strongly related to anthocyanin quantities. The accumulation of LhMYB12 transcripts in Tepals varied between seven cultivars in the same order, and transcription levels were positively correlated with pigment quantities. This suggests that the levels of transcription of LhMYB12 vary among the different cultivars and subsequently affect the quantities of pigment in Tepals. These results indicate that LhMYB12 determines anthocyanin pigmentation and generates the variation in anthocyanin colour hue in lily Tepals.
Sergi Munné-bosch - One of the best experts on this subject based on the ideXlab platform.
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Hormonal Sensitivity Decreases During the Progression of Flower Senescence in Lilium longiflorum
Journal of Plant Growth Regulation, 2016Co-Authors: Marta Cubría-radío, Laia Arrom, Sandra Puig, Sergi Munné-boschAbstract:Although lilies (Lilium sp.) are the fourth sold cut flower in the world, much remains to be discovered about the senescence and post-harvest physiology of these ethylene-insensitive flowers. This study investigated the hormonal regulation of flower senescence in Lilium longiflorum with a focus on the possible changes in sensitivity to phytohormones during the progression of Tepal senescence. After characterizing the hormonal profile of L. longiflorum ‘White Heaven’ Tepals from anthesis to complete wilting, we evaluated the changes in hormonal sensitivity during senescence by application of a combination of gibberellins and cytokinins at various times post anthesis. We observed a progressive loss of sensitivity to the hormonal treatment: from an increase of more than 2 days in flower lifespan when applied one day after anthesis, to a complete loss of vase-life prolongation when treated at the fourth day after anthesis or later. These observations were accompanied by various changes in the underlying hormonal contents, especially in the gibberellins and abscisic acid (ABA) profile, which was dependent on the application time. The results not only confirm the role of gibberellins and cytokinins as inhibitors, and ABA as a promoter of senescence, but also reveal a progressive loss in hormonal sensitivity and a hormonal cross-talk during the progression of senescence in Tepals of L. longiflorum. We conclude that both hormonal levels and sensitivity modulate the progression of Tepal senescence in L. longiflorum.
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Auxin involvement in Tepal senescence and abscission in Lilium: a tale of two lilies
Journal of experimental botany, 2014Co-Authors: Lara Lombardi, Laia Arrom, Sergi Munné-bosch, Lorenzo Mariotti, Riccardo Battelli, Piero Picciarelli, Peter Kille, Tony Stead, Hilary J. RogersAbstract:Petal wilting and/or abscission terminates the life of the flower. However, how wilting and abscission are coordinated is not fully understood. There is wide variation in the extent to which petals wilt before abscission, even between cultivars of the same species. For example, Tepals of Lilium longiflorum wilt substantially, while those of the closely related Lilium longiflorum×Asiatic hybrid (L.A.) abscise turgid. Furthermore, close comparison of petal death in these two Lilium genotypes shows that there is a dramatic fall in fresh weight/dry weight accompanied by a sharp increase in ion leakage in late senescent L. longiflorum Tepals, neither of which occur in Lilium L.A. Despite these differences, a putative abscission zone was identified in both lilies, but while the detachment force was reduced to zero in Lilium L.A., wilting of the fused Tepals in L. longiflorum occurred before abscission was complete. Abscission is often negatively regulated by auxin, and the possible role of auxin in regulating Tepal abscission relative to wilting was tested in the two lilies. There was a dramatic increase in auxin levels with senescence in L. longiflorum but not in Lilium L.A. Fifty auxin-related genes were expressed in early senescent L. longiflorum Tepals including 12 ARF-related genes. In Arabidopsis, several ARF genes are involved in the regulation of abscission. Expression of a homologous transcript to Arabidopsis ARF7/19 was 8-fold higher during senescence in L. longiflorum compared with abscising Lilium L.A., suggesting a conserved role for auxin-regulated abscission in monocotyledonous ethylene-insensitive flowers.
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Hormonal changes during flower development in floral tissues of Lilium
Planta, 2012Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Much effort has been focussed on better understanding the key signals that modulate floral senescence. Although ethylene is one of the most important regulators of floral senescence in several species, Lilium flowers show low sensitivity to ethylene; thus their senescence may be regulated by other hormones. In this study we have examined how (1) endogenous levels of hormones in various floral tissues (outer and inner Tepals, androecium and gynoecium) vary throughout flower development, (2) endogenous levels of hormones in such tissues change in cut versus intact flowers at anthesis, and (3) spray applications of abscisic acid and pyrabactin alter flower longevity. Results show that floral tissues behave differently in their hormonal changes during flower development. Cytokinin and auxin levels mostly increased in Tepals prior to anthesis and decreased later during senescence. In contrast, levels of abscisic acid increased during senescence, but only in outer Tepals and the gynoecium, and during the latest stages. In addition, cut flowers at anthesis differed from intact flowers in the levels of abscisic acid and auxins in outer Tepals, salicylic acid in inner Tepals, cytokinins, gibberellins and jasmonic acid in the androecium, and abscisic acid and salicylic acid in the gynoecium, thus showing a clear differential response between floral tissues. Furthermore, spray applications of abscisic acid and pyrabactin in combination accelerated the latest stages of Tepal senescence, yet only when flower senescence was delayed with Promalin. It is concluded that (1) floral tissues differentially respond in their endogenous variations of hormones during flower development, (2) cut flowers have drastic changes in the hormonal balance not only of outer and inner Tepals but also of androecium and gynoecium, and (3) abscisic acid may accelerate the progression of Tepal senescence in Lilium .
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Sucrose accelerates flower opening and delays senescence through a hormonal effect in cut lily flowers.
Plant science : an international journal of experimental plant biology, 2012Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Sugars are generally used to extend the vase life of cut flowers. Such beneficial effects have been associated with an improvement of water relations and an increase in available energy for respiration by floral tissues. In this study we aimed at evaluating to what extent (i) endogenous levels of sugars in outer and inner Tepals, androecium and gynoecium are altered during opening and senescence of lily flowers; (ii) sugar levels increase in various floral tissues after sucrose addition to the vase solution; and (iii) sucrose addition alters the hormonal balance of floral tissues. Results showed that endogenous glucose levels increased during flower opening and decreased during senescence in all floral organs, while sucrose levels increased in outer and inner Tepals and the androecium during senescence. Sucrose treatment accelerated flower opening, and delayed senescence, but did not affect Tepal abscission. Such effects appeared to be exerted through a specific increase in the endogenous levels of sucrose in the gynoecium and of glucose in all floral tissues. The hormonal balance was altered in the gynoecium as well as in other floral tissues. Aside from cytokinin and auxin increases in the gynoecium; cytokinins, gibberellins, abscisic acid and salicylic acid levels increased in the androecium, while abscisic acid decreased in outer Tepals. It is concluded that sucrose addition to the vase solution exerts an effect on flower opening and senescence by, among other factors, altering the hormonal balance of several floral tissues.
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Tocopherol composition in flower organs of Lilium and its variations during natural and artificial senescence
Plant Science, 2010Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Although the biosynthesis and function of tocopherols (vitamin E) in leaves and seeds have been studied in detail, their occurrence within other plant organs/tissues is still poorly understood. In an attempt to better understand the occurrence and possible functions of tocopherols in flowers, we measured the concentrations of the four tocopherol homologues in floral organs of Lilium (including the gynoecium, androecium, and inner and outer Tepals), and evaluated their variations in Tepals of cut, senescing flowers (artificial senescence) compared to controls (natural senescence). Results showed that flowers accumulated α-tocopherol at significant amounts, while γ-tocopherol was present at much lower concentrations. The androecium was the organ showing the highest amounts of tocopherols, with a specific accumulation in the pollen, while tocopherols were not present in the gynoecium. Inner and outer Tepals also contained significant amounts of α- and γ-tocopherol, whose levels increased during senescence. α-Tocopherol increased in both outer and inner Tepals earlier and to a higher extent during senescence of cut flowers than in controls. The lowest concentrations of tocopherols were found at the beginning of Tepal development (in green Tepals), while the highest concentrations were found in chlorophyll-free, senescing Tepals, especially in cut flowers. It is concluded that (i) tocopherols accumulate in outer and inner Tepals, and in the androecium of Lilium flowers, particularly in the pollen, and (ii) tocopherols increase with the progression of Tepal senescence, and most particularly in cut flowers, which show advanced senescence (reduced longevity).
Wilkin Paul - One of the best experts on this subject based on the ideXlab platform.
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Figure 1 from: Wilkin P, Muasya AM (2015) Clarifying the Dioscorea buchananii Benth. species complex: a new potentially extinct subspecies for South Africa. PhytoKeys 48: 51-72. https://doi.org/10.3897/phytokeys.48.6806
2015Co-Authors: Muasya A. Muthama, Wilkin PaulAbstract:Figure 1 - Dioscorea buchananii Benth. subsp. undatiloba vegetative and reproductive morphology A Habit of male plant with axillary inflorescences B Apical part of male inflorescence showing Tepal shape and habit and bud shape C Rehydrated male flower with apical part of pedicel showing stamen morphology (NB Tepal and stamen habit influenced by specimen preparation) D Fully opened out rehydrated male flower from above showing Tepal shape, torus and pistillode E Female flower with ovary at late anthesis, Tepals ascending F Female flower with 3 Tepals removed showing torus, staminodia and gynoecium G Immature capsule with pedicel, floral bract and persistent Tepals at apex H Leaf of KwaZuluNatal form of Dioscorea buchananii Benth. subsp. undatiloba. Scale bar: A, H 3 cm; B 7 mm; C, D, E 5 mm; F 3 mm; G 2 cm. From Breyer in TM 23387 (A), Junod 2182 (B, G), Medley Wood 11673 (C, D) Gerrard & McKen 1617 (E, F) Medley Wood 12969 (H). Drawn by Lucy Smith
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Figure 2 from: Wilkin P, Muasya AM (2015) Clarifying the Dioscorea buchananii Benth. species complex: a new potentially extinct subspecies for South Africa. PhytoKeys 48: 51-72. https://doi.org/10.3897/phytokeys.48.6806
2015Co-Authors: Muasya A. Muthama, Wilkin PaulAbstract:Figure 2 - Dioscorea multiloba Kunth vegetative and reproductive morphology. A Habit of male plant with axillary inflorescences B Apical part of male inflorescence showing Tepal shape and habit and bud shape habit C Lobed leaf showing venation of upper surface and forerunner tip D Male flower from above showing filament habit E Male flower with 3 Tepals and part of torus removed showing torus shape, pistillode and associated concavities in torus surface F Female flower with 3 Tepals and part of torus removed showing torus shape, staminodia and gynoecium G Female inflorescence showing Tepal habit and ovaries H Infructescence showing some submature capsules with persistent Tepals J Seed showing wing shape. Scale bar: A, C 3 cm; B 7 mm; D, E 4 mm; F 3 mm; G, H 2.5 cm; J 2 cm. From Ward 3076 (A, B, D, E), Medley Wood 329 (F, G), Gueinzius s.n. (H, J) and a photograph (C). Drawn by Lucy Smith
Laia Arrom - One of the best experts on this subject based on the ideXlab platform.
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Hormonal Sensitivity Decreases During the Progression of Flower Senescence in Lilium longiflorum
Journal of Plant Growth Regulation, 2016Co-Authors: Marta Cubría-radío, Laia Arrom, Sandra Puig, Sergi Munné-boschAbstract:Although lilies (Lilium sp.) are the fourth sold cut flower in the world, much remains to be discovered about the senescence and post-harvest physiology of these ethylene-insensitive flowers. This study investigated the hormonal regulation of flower senescence in Lilium longiflorum with a focus on the possible changes in sensitivity to phytohormones during the progression of Tepal senescence. After characterizing the hormonal profile of L. longiflorum ‘White Heaven’ Tepals from anthesis to complete wilting, we evaluated the changes in hormonal sensitivity during senescence by application of a combination of gibberellins and cytokinins at various times post anthesis. We observed a progressive loss of sensitivity to the hormonal treatment: from an increase of more than 2 days in flower lifespan when applied one day after anthesis, to a complete loss of vase-life prolongation when treated at the fourth day after anthesis or later. These observations were accompanied by various changes in the underlying hormonal contents, especially in the gibberellins and abscisic acid (ABA) profile, which was dependent on the application time. The results not only confirm the role of gibberellins and cytokinins as inhibitors, and ABA as a promoter of senescence, but also reveal a progressive loss in hormonal sensitivity and a hormonal cross-talk during the progression of senescence in Tepals of L. longiflorum. We conclude that both hormonal levels and sensitivity modulate the progression of Tepal senescence in L. longiflorum.
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Auxin involvement in Tepal senescence and abscission in Lilium: a tale of two lilies
Journal of experimental botany, 2014Co-Authors: Lara Lombardi, Laia Arrom, Sergi Munné-bosch, Lorenzo Mariotti, Riccardo Battelli, Piero Picciarelli, Peter Kille, Tony Stead, Hilary J. RogersAbstract:Petal wilting and/or abscission terminates the life of the flower. However, how wilting and abscission are coordinated is not fully understood. There is wide variation in the extent to which petals wilt before abscission, even between cultivars of the same species. For example, Tepals of Lilium longiflorum wilt substantially, while those of the closely related Lilium longiflorum×Asiatic hybrid (L.A.) abscise turgid. Furthermore, close comparison of petal death in these two Lilium genotypes shows that there is a dramatic fall in fresh weight/dry weight accompanied by a sharp increase in ion leakage in late senescent L. longiflorum Tepals, neither of which occur in Lilium L.A. Despite these differences, a putative abscission zone was identified in both lilies, but while the detachment force was reduced to zero in Lilium L.A., wilting of the fused Tepals in L. longiflorum occurred before abscission was complete. Abscission is often negatively regulated by auxin, and the possible role of auxin in regulating Tepal abscission relative to wilting was tested in the two lilies. There was a dramatic increase in auxin levels with senescence in L. longiflorum but not in Lilium L.A. Fifty auxin-related genes were expressed in early senescent L. longiflorum Tepals including 12 ARF-related genes. In Arabidopsis, several ARF genes are involved in the regulation of abscission. Expression of a homologous transcript to Arabidopsis ARF7/19 was 8-fold higher during senescence in L. longiflorum compared with abscising Lilium L.A., suggesting a conserved role for auxin-regulated abscission in monocotyledonous ethylene-insensitive flowers.
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Hormonal changes during flower development in floral tissues of Lilium
Planta, 2012Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Much effort has been focussed on better understanding the key signals that modulate floral senescence. Although ethylene is one of the most important regulators of floral senescence in several species, Lilium flowers show low sensitivity to ethylene; thus their senescence may be regulated by other hormones. In this study we have examined how (1) endogenous levels of hormones in various floral tissues (outer and inner Tepals, androecium and gynoecium) vary throughout flower development, (2) endogenous levels of hormones in such tissues change in cut versus intact flowers at anthesis, and (3) spray applications of abscisic acid and pyrabactin alter flower longevity. Results show that floral tissues behave differently in their hormonal changes during flower development. Cytokinin and auxin levels mostly increased in Tepals prior to anthesis and decreased later during senescence. In contrast, levels of abscisic acid increased during senescence, but only in outer Tepals and the gynoecium, and during the latest stages. In addition, cut flowers at anthesis differed from intact flowers in the levels of abscisic acid and auxins in outer Tepals, salicylic acid in inner Tepals, cytokinins, gibberellins and jasmonic acid in the androecium, and abscisic acid and salicylic acid in the gynoecium, thus showing a clear differential response between floral tissues. Furthermore, spray applications of abscisic acid and pyrabactin in combination accelerated the latest stages of Tepal senescence, yet only when flower senescence was delayed with Promalin. It is concluded that (1) floral tissues differentially respond in their endogenous variations of hormones during flower development, (2) cut flowers have drastic changes in the hormonal balance not only of outer and inner Tepals but also of androecium and gynoecium, and (3) abscisic acid may accelerate the progression of Tepal senescence in Lilium .
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Sucrose accelerates flower opening and delays senescence through a hormonal effect in cut lily flowers.
Plant science : an international journal of experimental plant biology, 2012Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Sugars are generally used to extend the vase life of cut flowers. Such beneficial effects have been associated with an improvement of water relations and an increase in available energy for respiration by floral tissues. In this study we aimed at evaluating to what extent (i) endogenous levels of sugars in outer and inner Tepals, androecium and gynoecium are altered during opening and senescence of lily flowers; (ii) sugar levels increase in various floral tissues after sucrose addition to the vase solution; and (iii) sucrose addition alters the hormonal balance of floral tissues. Results showed that endogenous glucose levels increased during flower opening and decreased during senescence in all floral organs, while sucrose levels increased in outer and inner Tepals and the androecium during senescence. Sucrose treatment accelerated flower opening, and delayed senescence, but did not affect Tepal abscission. Such effects appeared to be exerted through a specific increase in the endogenous levels of sucrose in the gynoecium and of glucose in all floral tissues. The hormonal balance was altered in the gynoecium as well as in other floral tissues. Aside from cytokinin and auxin increases in the gynoecium; cytokinins, gibberellins, abscisic acid and salicylic acid levels increased in the androecium, while abscisic acid decreased in outer Tepals. It is concluded that sucrose addition to the vase solution exerts an effect on flower opening and senescence by, among other factors, altering the hormonal balance of several floral tissues.
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Tocopherol composition in flower organs of Lilium and its variations during natural and artificial senescence
Plant Science, 2010Co-Authors: Laia Arrom, Sergi Munné-boschAbstract:Although the biosynthesis and function of tocopherols (vitamin E) in leaves and seeds have been studied in detail, their occurrence within other plant organs/tissues is still poorly understood. In an attempt to better understand the occurrence and possible functions of tocopherols in flowers, we measured the concentrations of the four tocopherol homologues in floral organs of Lilium (including the gynoecium, androecium, and inner and outer Tepals), and evaluated their variations in Tepals of cut, senescing flowers (artificial senescence) compared to controls (natural senescence). Results showed that flowers accumulated α-tocopherol at significant amounts, while γ-tocopherol was present at much lower concentrations. The androecium was the organ showing the highest amounts of tocopherols, with a specific accumulation in the pollen, while tocopherols were not present in the gynoecium. Inner and outer Tepals also contained significant amounts of α- and γ-tocopherol, whose levels increased during senescence. α-Tocopherol increased in both outer and inner Tepals earlier and to a higher extent during senescence of cut flowers than in controls. The lowest concentrations of tocopherols were found at the beginning of Tepal development (in green Tepals), while the highest concentrations were found in chlorophyll-free, senescing Tepals, especially in cut flowers. It is concluded that (i) tocopherols accumulate in outer and inner Tepals, and in the androecium of Lilium flowers, particularly in the pollen, and (ii) tocopherols increase with the progression of Tepal senescence, and most particularly in cut flowers, which show advanced senescence (reduced longevity).
Zhiduan Chen - One of the best experts on this subject based on the ideXlab platform.
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Comparative Flower and Inflorescence Organogenesis among Genera of Betulaceae: Implications for Phylogenetic Relationships
Botanical Review, 2017Co-Authors: Junyi Zhu, Lifan Zhang, Baoqing Ren, Min Chen, You Zhou, Yu Liang, Zhiduan ChenAbstract:Betulaceae have simple flowers but complex inflorescences. Recent phylogenetic analyses using molecular data have produced robust phylogenetic trees of Betulaceae. In this study, we evaluated the phylogenetic value of comparative organogenetic data of reproductive organs in the context of molecular phylogenies. Flower and inflorescence developmental processes of 21 species from all six genera in Betulaceae were documented with scanning electron microscopy. In each pistillate cyme, there are one primary bract, two secondary bracts, and two or three flowers in the six genera; only in Alnus are there two tertiary bracts on the abaxial side. The pistillate flower of all genera but Alnus has Tepal primordia. Two Tepals stop developing early on, resulting in the lack of Tepals in mature flowers of Betula; while the Tepals are initiated from a common circular primordium at the base of pistil in Corylus, Ostryopsis, Carpinus, and Ostrya, and the developed Tepals with irregular shape and unstable number of lobes are adnate to the top of the pistil. In staminate organogenesis, each cyme has one primary bract and three flowers in all genera; two secondary bracts are only present in Alnus, Betula, and Corylus. Staminate flowers have no Tepals except in Alnus and Betula, and exhibit high variation in number of stamens among genera. The number of secondary and tertiary bracts in each pistillate and staminate cyme, as well as the presence of Tepals in pistillate and staminate flowers was clarified in all genera. Micro-morphological characters were used to infer the phylogenetic relationships of genera and sections of Betulaceae. Our analyses support the division of two subfamilies: Betuloideae (Alnus and Betula) and Coryloideae (Corylus, Carpinus, Ostrya, and Ostryopsis), and three tribes: Betuleae (Alnus and Betula), Coryleae (Corylus), and Carpineae (Carpinus, Ostrya, and Ostryopsis). The results agree with those from molecular phylogenetic studies, and suggest that micro-morphological characters are phylogenetically informative in Betulaceae, and reproductive organs of Betulaceae have evolved in the direction of reduction in bracts and Tepals.
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Floral ontogeny of Schisandra chinensis (Schisandraceae): implications for androecial evolution within Schisandra and Kadsura
Plant Systematics and Evolution, 2012Co-Authors: Xiao-yu Dong, Richard M K Saunders, Zhiduan ChenAbstract:The organogenesis of staminate and carpellate flowers of Schisandra chinensis (Schisandraceae) was investigated with scanning electron microscopy, with observations on the development of Tepals reported for the first time. The results showed that there is no interval between the initiation of the last Tepal and that of the first stamen or carpel, and that the shapes of Tepal, stamen, and carpel primordia are similar. The Tepals and stamens of staminate flowers are initiated acropetally in a continuous spiral Fibonacci phyllotaxis, with no carpel structures observed; the filaments are not connate. The organogenesis of the carpellate flowers is similar to that of the staminate flowers, but with no evidence of stamen development. The carpels are ascidiate without postgenital fusion. Three androecial characters of Schisandra and Kadsura are discussed in a phylogenetic context. The subglobose or obovoid androecium of Schisandrapropinqua and Schisandra plena may be homologous with that in sections Kadsura and Sarcocarpon. The plesiomorphic form of the androecium within the two genera is likely to be elongate with more than ten free stamens.
