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Long-chain esters (LCEs) are known to affect aroma perception, but the mechanism of their effects remains unclear. In this study, ethyl palmitate (EP), an important LCE in Osmanthus fragrans flower absolute (OFFA), was selected as a target to identify its role and mechanism. The release characteristics of 10 aroma compounds from OFFA with and without EP were obtained by headspace gas chromatography mass spectrometry (HS-GC/MS) and olfactometry evaluation, respectively. The results show that EP changes the release behaviors of volatile compounds in solution, increases their olfactory detection thresholds (ODTs), and reduces the equilibrium headspace concentrations. According to Whitman's two-film model, EP was found to change the partition coefficients and mass transfer coefficients of the compounds between the liquid and gas phases. This indicates that EP plays an important role in the scent formation of a flavor product and that it is very valuable for the style design of the flavor product. [ABSTRACT FROM AUTHOR]

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Background: Podostemaceae is the largest family of strictly aquatic angiosperms. Species of this family possess unusual morphological and reproductive characters, grow attached to rocks in rivers with strong currents, and have a life cycle tightly linked to seasonality. Due to its reduced floral structures, which characterizes most species, the analysis of developmental stages and events such as anthesis or stigma receptivity has proven difficult. Question: How floral morphology, floral development and stigma receptivity of different stages of flower development of Marathrum rubrum Novelo & C. T. Philbrick are related among them? Studied species: Marathrum rubrum Novelo & C. T. Philbrick. Study site and dates: Horcones River, Jalisco, Mexico. January, 2014 and 2015. Methods: We made an in situ and lab analyses of flower morphology to assess the relationships between flower morphology, stages of development, reproductive structures, and stigma receptivity, during different stages of flower development. Results: When flowers emerge from the spathella, both the ovules and pollen grains are fully developed, implying that sporogenesis and gametogenesis take place within the stem while the plant is still submerged. Conclusions: The morphological changes observed in the flowers of M. rubrum during the analyzed stages are related only to events associated with fertilization and fruit development. The time-course of morphological changes in the flowers, from anthesis to fruit formation, lasts 20 to 30 days. The detailed observation of the aerial reproductive biology of M. rubrum bears important implications to the genetic structure of populations, plant fitness and conservation biology in threatened environments.

The vascular anatomy and morphology structure of the Allium sativum flower were studied. New morphological features were investigated for taxonomy in Amaryllidaceae. 15 flowers of Allium sativum were sectioned using standard methods of Paraplast embedding and serial sectioning at 20 mm thickness. Sections were stained with Safranin and Astra Blau and mounted in Eukitt. We find three vertical zones in the Allium sativum gynoecium: synascidiate, symplicate and hemisymplicate. The micromorphology and vascular flower anatomy were described by using flowers transverse sections. The Allium sativum peduncle contains 6 vascular bundles - three large and three small ones, which branch out and form a circle of vascular bundles - a vascular cylinder, from which at the level of the peduncle they depart six pairs of vascular bundles, traces of tepals, traces of stamens and above - traces of dorsal carpel bundles. Stamens depart from the ovary wall. In the center of the ovary, there remains a circle of small vascular bundles- the roots of the ventral complex, which were reorganized above, with the appearance of locules, into ventral carpel bundles, which supplied ovules and end blindly. In the same way, the dorsal carpel bundles also end blindly. The trace of the ovules was single-bundle. The traces of the dorsal carpel bundles were single-bundled. There were 6 ovules, 2 ovules in each locule. Traces of stamens and traces of inner and outer tepals were single-bundled. The study of new features of vascular anatomy and flower morphology will make a significant contribution to the taxonomy of the Amaryllidaceae family. [ABSTRACT FROM AUTHOR]

The flowers of the species of Malpighiaceae in the Neotropical Region are relatively uniform in their morphology due to their dependence on oil-collecting bees as their main pollinators. However, many species of the genus Galphimia seem to have acquired a different floral syndrome, lacking markedly zygomorphic flowers and developed elaiophores in the calyx. Likewise, these species present anthers with great development, probably in response to the selection of pollinators that collect pollen. Galphimia australis incorporated some of these traits but also retained some residual characteristics typical of species pollinated by oil bees. This leads to many questions on how these flowers ensure their pollination. Inquiring about the reduction or modification of these characteristics allows us to understand how G. australis achieves a different pollination syndrome. In this research, we carry out a detailed morphological and anatomical study of the flowers and pollen grain devolvement of G. australis and floral visitors were observed and captured. Results were analyzed in order to determine how this species changed from the oil-floral syndrome, typical of neotropical Malpighiaceae, to one syndrome with pollen as the main reward. [ABSTRACT FROM AUTHOR]

We studied the structure of the flowers of the Cyrtanthus elatus (Jacq.) Traub. The morphometric parameters, morphology, anatomy, and vascular anatomy of the ovary and the flower are generally described. There are three vertical zones present in the C. elatus gynoecium: symplicate, hemisymplicate, and asymplicate vertical zones. Synascidiate zone is absent. Septal nectaries appear in the symplicate zone and have a height of about 1920 μm. C. elatus peduncle contains 20 vascular bundles, which unite above and form a massive vascular cylinder, from which at the level of the receptacle depart traces of dorsal vascular bundles, traces of septal vascular bundles, traces of tepals, which give rise to traces of stamens. In the center of the ovary remains a group of small vascular bundles-the roots of the ventral complex, which above when the locule appear reorganized into 6 massive vascular bundles-the ventral vascular bundles of the carpel, which feed the ovules. The trace of the ovule is single-bundle. Traces of dorsal and septal vascular bundles of the carpel are two-bundle. Above the locules, the ventral vascular bundles of the carpel are merge with the dorsal vascular bundles and form a dorsal vein. There are a lot of ovules, in a section in each locule are 2-3 ovules. Traces of the inner tepals comprise 10 vascular bundles, traces of the outer tepals comprise 15 vascular bundles. Traces of stamens are single-bundle, depart from tepal traces. [ABSTRACT FROM AUTHOR]

Quantifying the relative contribution of functional and developmental constraints on phenotypic variation is a long-standing goal of macroevolution, but it is often difficult to distinguish different types of constraints. Alternatively, selection can limit phenotypic (co)variation if some trait combinations are generally maladaptive. The anatomy of leaves with stomata on both surfaces (amphistomatous) present a unique opportunity to test the importance of functional and developmental constraints on phenotypic evolution. The key insight is that stomata on each leaf surface encounter the same functional and developmental constraints but potentially different selective pressures because of leaf asymmetry in light capture, gas exchange, and other features. Independent evolution of stomatal traits on each surface imply that functional and developmental constraints alone likely do not explain trait covariance. Packing limits on how many stomata can fit into a finite epidermis and cell size–mediated developmental integration are hypothesized to constrain variation in stomatal anatomy. The simple geometry of the planar leaf surface and knowledge of stomatal development make it possible to derive equations for phenotypic (co)variance caused by these constraints and compare them with data. We analyzed evolutionary covariance between stomatal density and length in amphistomatous leaves from 236 phylogenetically independent contrasts using a robust Bayesian model. Stomatal anatomy on each surface diverges partially independently, meaning that packing limits and developmental integration are not sufficient to explain phenotypic (co)variation. Hence, (co)variation in ecologically important traits like stomata arises in part because there is a limited range of evolutionary optima. We show how it is possible to evaluate the contribution of different constraints by deriving expected patterns of (co)variance and testing them using similar but separate tissues, organs, or sexes. [ABSTRACT FROM AUTHOR]

• Exogenous application of five plant growth regulators (stimulant, stem retardant) were assessed on Lilium. • BA and GA 3 at 50 mg l−1 significantly improve lily flower postharvest flower component including vase life. • Ancymidol at rate of 50 l−1 was effective in reducing stem elongation by 23 % to 41 % without adverse side effects on leaf and flower postharvest quality. • Ethephon successfully reduced stem length (28 %-53 %) and resulted in 67 % to 100 % flower abortion across lily cultivars. Plant growth regulators (PGRs) are chemical compounds that can potentially stimulate cut flowers growth and development and play key regulatory roles in plant responses to the surrounding environment. The aim of this study was to assess how the application of five PGRs; 6-Benzylaminopurine (BA, cytokinins), indole-3-acetic acid (IAA, auxins), gibberellic acid (GA 3 , Gibberellins), Ethephon (ethylene stimulant, stem retardant) and Ancymidol (stem retardant) affected plant morpho-physiology, leaf and stem anatomy, yield and flower quality of lily (Lilium × elegans cvs. MayTime and Fangio). Two experiments were carried out; in the first experiment, PGR stimulants (BA, IAA, GA 3) were applied at rates of 50 and 200 mg l−1 on days 30 and 40 (vegetative stage). The results showed that BA and GA 3 at 50 mg l−1 significantly increased leaf area in 'Fangio' by 44 %-69 %. In addition, BA, IAA and GA 3 at lower rate (50 mg l−1) significantly increased flower number per stem ('Fangio' 29 %-47 %; 'Maytime' 20 %-70 %), and vase life ('Fangio', 16 %-32 %; 'Maytime' 17 %-18 %). In terms of anatomy, BA at both rates (50 and 200 mg l−1) increased leaf thickness while GA 3 at 50 mg l−1 increased the total number of vascular bundles in the stem, compared to control untreated ones. The cultivar 'Maytime' had higher leaf area (200 %), plant height (73 %), number of days to flowering (49 %), brightness or lightness color L* (106 %), lower number of flowers per stem (43 %), and shorter vase life (21 %) than 'Fangio'. In the second experiment, both lily cultivars received two foliar sprays of growth retardants; Ancymidol at rates of 50 and 200 mg l−1 and Ethephon at 50 and 500 mg l−1. Ancymidol at 50 mg l−1 was effective in reducing stem elongation by 23 % to 41 % without adverse side effects on leaf and flower quality. In fact, lilies plants treated with Ancymidol at 50 mg l−1 had similar leaf area, chlorophyll content, photosynthesis rate, stomatal conductance, transpiration, flower diameter, number per stem and vase life to that of control non-treated plants. On the other hand, reduced stem length (28 %-53 %) resulted from Ethephon application was associated with 67 % to 100 % flower abortion across lily cultivars. Overall, this study revealed that foliar application of PGRs (BA, GA 3 and IAA) at a rate of 50 mg l−1 hold promise for improving flower quality of lily cultivars, specifically, flower numbers per stem and vase life. In addition, 50 mg l−1 of Ancymidol is efficient in producing compact plants while maintaining leaf and flower quality components. [ABSTRACT FROM AUTHOR]

Detailed anatomical studies of flowers and fruits may render traits of phylogenetic importance, but are still rare in the Boraginales. An Old World clade of Cordia comprises many dioecious species, but the floral anatomy is largely unexplored and, hence, the structural basis for sex separation. Fresh material of buds, functionally unisexual flowers and fruits were studied using a stack shot camera. Fixed such material of Cordia crenata, C. cf. grandicalyx and C. sinensis was sectioned using a microtome and stained with safranin red and astra blue, and the gynoecial surface was studied using SEM. The stamens of the female flowers are largely intact, but do not produce pollen, whereas the gynoecium of the male flowers is highly reduced though develops ovules lacking an embryo sac. The morphologically rather unreduced stamens of the female flower may have undergone a shift of function from producing pollen towards attracting pollinators by optical signals. The outer parenchyma of the gynoecium is strongly stained and after fertilisation, one through three ovules are maturing towards seeds. The presence of more than a single seed enclosed in the undivided endocarp is rare in Cordiaceae. [ABSTRACT FROM AUTHOR]

The structure and histochemistry of the floral nectary of Bauhinia monandra Kurz (Fabaceae) were investigated. Besides possessing medicinal properties, this tree is also used in the recovery of degraded areas and urban arborization. Nectaries samples were obtained from newly bloomed flowers. The nectary was located on the tubular hypanthium. This tube was partially coated by a nectary epidermis, whose cells had secretory features such as a relatively large nucleus, a dense cytoplasm, and small vacuoles. Subjacent to the nectary epidermis, there was a nectary parenchyma with eight to fifteen layers of cells which also have secretory features. Both the nectary epidermis and nectary parenchyma possessed starch grains. Subjacent to the nectary parenchyma passed collateral to amphicribral concentric vascular bundles constituted by more phloem than xylem. Although these vascular bundles did not emit terminations directed to the nectary parenchyma, the arrangement of the latter about the former suggests the supply of nectar precursors by the vascularisation. In the basal region of the hypanthium tube occurred modified stomata which were probably the main route of nectar release; and tector trichomes, possibly involved in the nectar retention. [ABSTRACT FROM AUTHOR]

Stingless bees, play an important role as pollinators of many flowering plants. The present study was aimed to know the floral resources foraged by stingless bee, Tetragonula nr. Pagdeni in Bengaluru, Karnataka through visual observations. Roving surveys were conducted and observation on the stingless bees visiting flowering plants were recorded from June 2021 to May 2022. A Total of 258 bee floral plant species, belonging to 68 different botanical families were documented. Most frequently foraged families were Asteraceae (28 species) and Fabaceae (27 species) followed by Bignoniaceae (14 species), Acanthaceae (11 species), Lamiaceae (10 species), Poaceae (10 species), Cucurbitaceae (9 species) and Solanaceae (8 species), besides 141 plant species coming under 60 other families. The flower colour, shape and size also influenced the foraging efficiency. Greater bee visitation was evident in white and yellow coloured flowers with open shape and small and medium sized flowers as compared to other. These results suggested that the studied site can provide floral resources to stingless bees throughout the year which is an important pre - requisite for maintaining stingless bee populations. [ABSTRACT FROM AUTHOR]

At least in one phase of postharvest, the flower stems of rose are exposed to the environment. The water they lose and the rehydration in the vase will depend on the temperature and anatomy of the flower stem. In this research, the moisture content of two cultivars of Rosa hybrida exposed to room temperature from 0 to 48 h was evaluated and the anatomy of the leaf and stem was described. In March 2019, flower stems of ‘Engagement’ and ‘Freedom’ roses were harvested, in a commercial greenhouse in Puebla, Mexico and transported dry to the laboratory of the Iztacala Faculty of Higher Studies, where they were spread out on a table. Evaluations were conducted every 8 h. In both cultivars, the initial moisture of stems and leaves was 75%. In those that were exposed for 24 hours, it was 66 and 57% for ‘Engagement’ and ‘Freedom’, respectively. The thickness of the cuticle and mesophyll was 96 and 26% greater in ‘Engagement’ than in ‘Freedom’ (180.9 and 2.4 μm). The stems of ‘Engagement’ had 331 vessels per mm² with 29.5 μm in diameter, those of ‘Freedom’ 402 of 26.5 μm. The ‘Engagement’ rose lost less water than ‘Freedom’ due to the greater thickness of its cuticle and amplitude of its mesophyll. The number of vessels had little effect on water loss or rehydration in the vase. In both cultivars, the flower stems could have a useful vase life even if they are exposed to the environment for 8 or 16 h without any protection, with longer times it decreases due to dehydration of the leaves. [ABSTRACT FROM AUTHOR]

Most Neotropical Malpighiaceae species are characterized by having zygomorphic flowers and oil glands in the sepals called elaiophores; these floral characteristics are associated with a particular pollination syndrome through oil-collecting bees. This work proposes a study about the structural characteristics of elaiophores in 18 species of Malpighiaceae present in Argentina. The main objectives are to describe the morphology and anatomy of the elaiophores, to detect variation in the number of glands, to compare similarities or differences in elaiophores of species belonging to different lineages, and to know about the potential pollinators and their association with the structural traits of the elaiophores. The morphology and the anatomy were studied using traditional methods of scanning electron and bright-field microscopes. Field trips were carried out to capture oil-collecting bee species on flowers, in different natural populations. Different measurements were taken in the flowers, elaiophores, and oil-collecting bees and were statistically analyzed. Although elaiophores showed a common pattern, some particularities in number, morphology, and anatomy were detected; few of these seem to be restricted to some groups of species phylogenetically related. As regards pollinators, a positive tendency was observed between the size of the flowers, elaiophores, and oil-collecting bees. However, the thickness of the cuticle presented a negative association with the size of the elaiophore and consequently with the floral diameter, which could be presumably related to the foraging behavior and/or the structure of oil-collecting apparatus of the bee species. [ABSTRACT FROM AUTHOR]

Vascular system blockages and a shortage of mechanistic support are important limitations on the vase life quality of cut flowers. These characteristics contribute to sensitivity to neck bending and senescence. In this study, the role of xylem anatomy in the process related to the high/low or continuous/discontinuous water absorption during vase life was investigated, and the physiological responses of 11 commercial cut rose cultivars were determined to explore the relationship between cut flower vessel anatomy and transpirational water loss. The results revealed that rose cultivars with a larger xylem diameter had the longest vase life, and there was a positive association between these two variables. The ethylene and malondialdehyde (MDA) concentrations were low in cultivars with a long vase life, showing the non-susceptibility of these cultivars to postharvest deterioration resulting from ethylene exposure and reactive oxygen species (ROS) production. Since vase life was not significantly correlated to stomata number and aperture, therefore, stomata status and density were not major factors that cause the incidence of cut rose stem bending, and a shorter vase life may result from lower water absorption. The principal component analysis (PCA) allows screening and detecting physiological parameters that significantly distinguish the most variation amongst the 11 studied cultivars and shows the relationships between the vase life and the water absorption parameters. This study provides some criteria for the identification and selection of the best treatments to prolong the vase longevity of different rose cultivars. • Different cultivars exhibited distinct variation in postharvest characterizations. • Short-life cultivars exhibited higher values of ethylene production and MDA content. • The vase life positively connected with xylem diameter and fiber cell wall diameter. • Water stress was the main factor that regulates vase life of tested cultivars. [ABSTRACT FROM AUTHOR]

Pollen grains have a relatively simple structure and microscopic size, with two or three cells surrounded by the protective sporoderm at maturity. The viability and efficiency of pollen transport from anther to stigma depends on pollen physiological properties, especially the relative water content of the vegetative cell. Pollen transport is a crucial fate for most angiosperms that depends on biotic pollinators and studies focusing on understanding the morpho-physiological properties of pollen grains are still scarce, especially to tropical open physiognomies as the Brazilian Cerrado. Therefore, we investigate some structural and physiological aspects of pollen grains from six native species naturally growing in one Cerrado area: Campomanesia pubescens (Myrtaceae), Caryocar brasiliense (Caryocaraceae), Erythroxylum campestre (Erythroxylaceae), Lippia lupulina (Verbenaceae), Pyrostegia venusta (Bignoniaceae), and Xylopia aromatica (Annonaceae). We selected dehiscent anthers and mature pollen grains to analyze (1) the anther wall and pollen microstructure, (2) the pollen water status at the time of anther dehiscence, and (3) the pollen chemical compounds. In all analyzed species, the anther and pollen developed in a successfully way, and except for Caryocar brasiliense, all species were able to emit pollen tubes in the germination tests. As expected for a dry and open environment, most species dispersed their pollen grains in a partially dehydrated form, as indicated by our harmomegathy experiment. As indicated by our study, the pollen ability in preventing dissection, maintaining its viability in a dry and hot environment during its transport from anther to stigma, may be related to the sporoderm apertures and to the reserve compounds, mainly carbohydrates in the form of hydrolysable starch grains. [ABSTRACT FROM AUTHOR]

Three Mediterranean Arbutus species and one natural hybrid, as well as three North American species and one Californian hybrid of unknown origin were studied microscopically; a comparison of the internal anatomy of the flowers of these species is reported for the first time. Anatomical features were found to be similar in general but unique to the Arbutus. However, the length of the anther appendages, the spurs, seems to provide a heritage trait linking the Californian hybrid Arbutus 'Marina' to the A. canariensis and support other morphological findings between the East Mediterranean hybrid, A. ×andrachnoides, and its parents A. andrachne and A. unedo. [ABSTRACT FROM AUTHOR]

The general morphology, micromorphology, and anatomy of the flowers of Clivia miniata, Clivia nobilis, and Scadoxus multiflorus were studied using light microscopy. The studied species have large syntepalous and trimerous flowers, short floral tubes with adnate stamens, and inferior ovaries that develop baccate fruit. The gynoecium in the studied species consists of synascidiate, symplicate, and hemisymplicate zones. The style is composed of postgenitally fused carpels. The few ovules are located in a locule in the synascidiate and symplicate zones in C. miniata and C. nobilis, whereas in S. multiflorus, solitary ovules occupy the synascidiate zone in each locule. The septal nectaries are located in the hemisymplicate zone and occupy the uppermost 29% to 56% of the ovary height. Septal nectaries are of the nonlabyrinthine lilioid-type, covered with secretory tissue only in its lower portion. Nectary channels are apical or subapical and open near the style base. A common pattern of the venation of the floral parts was observed in all species: Tepal traces and stamen traces were fused in the ovary wall, the style was supplied by dorsal carpellary bundles, and ovules were supplied by ventral carpellary bundles entering the ovary from the bottom. The observed gynoecium inner structure provides adaptations for the development of fleshy fruit, with thickened parenchymous ovary wall, ovary base, and ovary roof, and numerous branched vascular bundles in the ovary wall around locules. [ABSTRACT FROM AUTHOR]

The article titled "A Journey Through the Amaryllidaceae: A Perspective from the Americas" presents a special issue about the plant family Amaryllidaceae. This family includes species distributed worldwide, with the highest taxonomic diversity in South America, Asia, and southern Africa. The article highlights the economic and ornamental importance of this family, as well as its relevance in the traditional medicinal practices of indigenous populations. The special issue brings together studies on representatives of the family in the American continent, with the aim of understanding their evolutionary history and increasing awareness about the Amaryllidaceae. The published articles cover different botanical areas and taxonomic levels within the family, including studies on systematics, cytogenetics, floral interactions, flower anatomy, and medicinal uses of plants in the family. [Extracted from the article]

Background: Interpretation of the floral structure of Zingiberaceae has long concentrated on the relationships of the androecial members. It suggested that labellum is composed of two structures rather than three or five, and glands are interpreted either as gynoecial part or as androecial members. Methods: Serial sections were used to observe the vasculature of normal and two-staminate flowers in Alpinia intermedia 'shengzhen'. Floral diagrams were drawn to interpret the morphological category of the floral organs and the relationships of the androecial members. Androecial vascular bundles were associated with carpellary dorsal bundles (CDBs) and parietal bundles (PBs) in a Zingiberales phylogeny setting using ancestral state reconstruction. Results: Anatomical observations demonstrate that the fertile stamen(s) incorporate parietal bundles both in normal and two-staminate flowers. The three appendages represent the three members of the outer whorl of the androecium, while the labellum represents the inner whorl of the androecium in the two-staminate flower. Reconstruction of the origin of the vascular system in the androecium suggests that the outer whorl of androecium receives its vascular supply from the CDBs, and the inner whorl of androecium receives from the PBs in both the basal banana group and the more derived ginger clade. Conclusions: The present study adds to a growing body of literature suggesting that the anatomy of abnormal flowers may not provide enough evidence for elucidating the relationships of the androecial members, and help us to better understand how the vascular system is constructed during the androecial petaloidy evolution. [ABSTRACT FROM AUTHOR]

Despite their ecological importance and wide distribution, Cordiaceae have not been subject to detailed anatomical study yet. We examined flower and fruit anatomies of Cordia nodosa and Varronia bonplandii (using paraffin sectioning and light microscopy) in comparison with other woody members of Boraginales. The internal architecture of the superior bicarpellate ovary resulted from the development of secondary septa including apical, basal and false septa, as reported also from other Boraginales. Novel characters of Cordiaceae were identified such as an extensive tissue surrounding the gynoecium of C. nodosa and a lignified cap on top of the endocarp in V. bonplandii. Fruits containing a single seed may have originated several times independently in Cordiaceae deriving from the four-seeded condition present today in most other non-capsular Boraginales. Distyly of V. bonplandii does not appear genetically fixed but may result from different ecological conditions. Hemianatropous ovules are now considered the derived character state in Cordiaceae, originating from anatropous ovules present in other Boraginales. Studies like this improve the knowledge about generative organs in general and identify phylogenetically informative characters. However, better knowledge of functional morphology and ecological importance regarding many traits identified require further investigations on the diversity of Cordiaceae. [ABSTRACT FROM AUTHOR]

The vascular anatomy and morphology structure of the flower of the Hymenocallis latifolia were studied. New morphological features in particular, vertical zonality of the gynoecium and vascular anatomy of the flower are not taken into account in the taxonomy of the family Amaryllidaceae. 10 flowers of Hymenocallis latifolia were sectioned using standard methods of Paraplast embedding and serial sectioning at 20 mkm thickness. Sections were stained with Safranin and Astra Blau and mounted in Eukitt. We investigated the presence of two vertical zones in the Hymenocallis latifolia gynoecium: symplicate and hemisymplicate. The micromorphology and vascular flower anatomy were described by using flowers transverse sections. Hymenocallis latifolia peduncle has 41 vascular bundles. The paired ventral bundles of the carpel supplied ovules. Above the locules, the ventral bundles of the carpel merge with the dorsal and septal vascular bundles, forming dorsal veins. Traces of dorsal vascular bundles of carpel are five-bundles, traces of septal bundles of carpel are three-bundles. Traces of outer tepals are thirteen-bundles, traces of inner tepals are nine-bundles. Traces of stamens are single-bundle. The new data helped to deepen the knowledge about the morphology and vascular anatomy features of Hymenocallis latifolia flowers and will help to compare the obtained morphological and anatomical features with the features studied earlier for members of the family Amaryllidaceae for further using them in taxonomy. [ABSTRACT FROM AUTHOR]

EAFIT University leads the "Science among Mountains" project in the Cartama Province, Southwest Antioquia, where more than 1100 children participate in active learning workshops on science and research. The children explore their environment, identify flowers and pollinating animals, study the anatomy of flowers, and experiment with the extraction of essential oils. The project, funded by the General System of Royalties and supervised by Minciencias, will be carried out in 40 rural educational sites until 2025. [Extracted from the article]

The stereotyped floral morphology of Neotropical Malpighiaceae species—zygomorphic and calyx with oil glands—is correlated with oil-bee pollination. In contrast, the floral trends of the Paleotropical lineages are actinomorphy and lack of calyx glands, probably due to the absence of oil-collecting bees. The Paleotropical genus Acridocarpus is an exception because of its zygomorphic, gland-bearing flowers. Glands throughout Acridocarpus inflorescences were morphoanatomically evaluated to verify the occurrence of patterns related to species and geographic distribution. Herbarium (25 species) and fresh samples of A. longifolius were processed according to standard anatomical techniques. To verify the presence of glucose and protein, strip tests were applied to the exudate. Fresh samples were fixed and submitted to histochemical tests. Based on the occurrence, number and placement of glands, three distribution patterns were recognized on the bracteole and ten on the calyx. Bract, bracteole and sepal glands have a typical nectary structure with a palisade-like epidermis and vascularized parenchyma. Glands were classified as short-stalked, sessile or immersed. Histochemical tests performed on bract and sepal glands of A. longifolius were positive for proteins, polysaccharides and phenolic compounds, and negative for oil compounds. Glucose and protein were detected in the exudate. These results allow us to recognize the glands in Acridocarpus inflorescences as nectaries. This comprehensive morphoanatomical study helps to clarify the correlation between patterns of floral morphology and secretion consumers, as well as to better understand floral evolution in Malpighiaceae across their dispersal events. [ABSTRACT FROM AUTHOR]

Androdioecy is one of the rarest sexual systems among plants, characterized by males co-occurring with hermaphrodites. Osmanthus delavayi (Oleaceae), an ornamental shrub from southern China, is known to have both male and hermaphrodite individuals, but little is known regarding the breeding system of this species and whether it is functionally androdioecious, and how this potentially evolved. In this study, we explore the characteristics of the breeding system of O. delavayi through the study of phenology, sex ratio, floral organ morphology, pollen number, stigma receptivity, artificial pollination, pollinators, and gene flow within and between populations, while also discussing the evolution and maintenance of androdioecy within the genus. The proportion of males was less than 0.5 and the out-crossing index (OCI) was 5. Morphological androdioecy was observed, with hermaphrodite flowers having fertile pistils, while male flowers had degenerated pistils. Males and hermaphrodites both had large amounts of small and fertile pollen grains, although the pollen number of males was ca. 1.21 × more than that of hermaphrodites, and pollen was generally smaller. Self-pollination was found to produce a much lower fruit set than outcrossing under natural conditions. Gene flow between males and hermaphrodites within a population was greater (1.007) than that between populations (0.753). All these results indicate that O. delavayi is functionally androdioecious, which may be an intermediate state in the evolutionary transition from hermaphroditism to dioecy. [ABSTRACT FROM AUTHOR]

OsMADS16, a class B floral organ identity gene, plays a pivotal role in stamen formation in rice. To date, little is known about the interacting partners of OsMADS16 except for several MADS-box proteins. In this study, we constructed a high-quality cDNA library of young panicles (< 5 cm in length) and performed yeast two-hybrid (Y2H) screening using OsMADS16 as bait. Eleven candidate proteins interacting with OsMADS16 were identified by Y2H and validated by BiFC and Co-IP assays. Subcellular localization results further confirmed the possibility of the interactions of OsMADS16 with 10 of the candidate proteins in natural rice cells. Bioinformatics analysis indicated that these partners exerted various molecular, cellular and physiological functions. Some of them were known or likely to be related to reproductive events, such as stamen primordium initiation, differentiation and development (OsMADS2, OsMADS4 and OsCOP9) and pollen development (OsbHLH40 and Os6PGDH). Our results provide an important reference for further research on OsMADS16-mediated regulation mechanism on floral organ development and pollen formation. [ABSTRACT FROM AUTHOR]

Silene latifolia is a dioecious flowering plant with sex chromosomes in the family Caryophyllaceae. Development of a gynoecium and stamens are suppressed in the male and female flowers of S. latifolia, respectively. Microbotryum lychnidis-dioicae promotes stamen development when it infects the female flower. If suppression of the stamen and gynoecium development is regulated by the same mechanism, suppression of gynoecium and stamen development is released simultaneously with the infection by M. lychnidis-dioicae. To assess this hypothesis, an asexual mutant without a gynoecium or stamen was infected with M. lychnidis-dioicae. A filament of the stamen in the infected asexual mutant was elongated at stages 11 and 12 of flower bud development as well as in the male, but the gynoecium did not form. Instead of the gynoecium, a filamentous structure was suppressed as in the male flower. Developmental suppression of the stamen was released by M. lychnidis-dioicae, but that of gynoecium development was not released. M. lychnidis-dioicae would have a function similar to stamen-promoting factor (SPF), since the elongation of the stamen that is not observed in the healthy asexual mutant was observed after stage 8 of flower bud development. An infection experiment also revealed that a deletion on the Y chromosome of the asexual mutant eliminated genes for maturation of tapetal cells because the tapetal cells did not mature in the asexual mutant infected with M. lychnidis-dioicae. [ABSTRACT FROM AUTHOR]

Sensory hair cells are mechanoreceptors required for hearing and balance functions. From embryonic development, hair cells acquire apical stereociliary bundles for mechanosensation, basolateral ion channels that shape receptor potential, and synaptic contacts for conveying information centrally. These key maturation steps are sequential and presumed coupled; however, whether hair cells emerging postnatally mature similarly is unknown. Here, we show that in vivo postnatally generated and regenerated hair cells in the utricle, a vestibular organ detecting linear acceleration, acquired some mature somatic features but hair bundles appeared nonfunctional and short. The utricle consists of two hair cell subtypes with distinct morphological, electrophysiological and synaptic features. In both the undamaged and damaged utricle, fate-mapping and electrophysiology experiments showed that Plp1+ supporting cells took on type II hair cell properties based on molecular markers, basolateral conductances and synaptic properties yet stereociliary bundles were absent, or small and nonfunctional. By contrast, Lgr5+ supporting cells regenerated hair cells with type I and II properties, representing a distinct hair cell precursor subtype. Lastly, direct physiological measurements showed that utricular function abolished by damage was partially regained during regeneration. Together, our data reveal a previously unrecognized aberrant maturation program for hair cells generated and regenerated postnatally and may have broad implications for inner ear regenerative therapies. [ABSTRACT FROM AUTHOR]

Male sterility (induced or natural) is a potential tool for commercial hybrid seed production in different crops. Despite numerous endeavors to understand the physiological, hereditary, and molecular cascade of events governing CMS in cotton, the exact biological process controlling sterility and fertility reconstruction remains obscure. During current study, RNA-Seq using Ion Torrent S5 platform is carried out to identify ‘molecular portraits’ in floral buds among the Cytoplasmic Genic Male Sterility (CGMS) line, its near-isogenic maintainer, and restorer lines. A total of 300, 438 and 455 genes were differentially expressed in CGMS, Maintainer, and Restorer lines respectively. The functional analysis using AgriGo revealed suppression in the pathways involved in biogenesis and metabolism of secondary metabolites which play an important role in pollen and anther maturation. Enrichment analysis showed dearth related to pollen and anther’s development in sterile line, including anomalous expression of genes and transcription factors that have a role in the development of the reproductive organ, abnormal cytoskeleton formation, defects in cell wall formation. The current study found aberrant expression of DYT1, AMS and cytochrome P450 genes involved in tapetum formation, pollen development, pollen exine and anther cuticle formation associated to male sterility as well as fertility restoration of CGMS. In the current study, more numbers of DEGs were found on Chromosome D05 and A05 as compared to other chromosomes. Expression pattern analysis of fourteen randomly selected genes using qRT-PCR showed high concurrence with gene expression profile of RNA-Seq analysis accompanied by a strong correlation of 0.82. The present study provides an important support for future studies in identifying interaction between cyto-nuclear molecular portraits, to accelerate functional genomics and molecular breeding related to cytoplasmic male sterility studies in cotton. [ABSTRACT FROM AUTHOR]

Ogura-type cytoplasmic male sterility (Ogura-CMS) has been widely used in the hybrid breeding industry for cruciferous vegetables. Turnip (Brassica rapa ssp. rapifera) is one of the most important local cruciferous vegetables in China, cultivated for its fleshy root as a flat disc. Here, morphological characteristics of an Ogura-CMS line ‘BY10-2A’ and its maintainer fertile (MF) line ‘BY10-2B’ of turnip were investigated. Ogura-CMS turnip showed a reduction in the size of the fleshy root, and had distinct defects in microspore development and tapetum degeneration during the transition from microspore mother cells to tetrads. Defective microspore production and premature tapetum degeneration during microgametogenesis resulted in short filaments and withered white anthers, leading to complete male sterility of the Ogura-CMS line. Additionally, the mechanism regulating Ogura-CMS in turnip was investigated using inflorescence transcriptome analyses of the Ogura-CMS and MF lines. The de novo assembly resulted in a total of 84,132 unigenes. Among them, 5,117 differentially expressed genes (DEGs) were identified, including 1,339 up- and 3,778 down-regulated genes in the Ogura-CMS line compared to the MF line. A number of functionally known members involved in anther development and microspore formation were addressed in our DEG pool, particularly genes regulating tapetum programmed cell death (PCD), and associated with pollen wall formation. Additionally, 185 novel genes were proposed to function in male organ development based on GO analyses, of which 26 DEGs were genotype-specifically expressed. Our research provides a comprehensive foundation for understanding anther development and the CMS mechanism in turnip. [ABSTRACT FROM AUTHOR]

P10 is a small, abundant baculovirus protein that accumulates to high levels in the very late stages of the infection cycle. It is associated with a number of intracellular structures and implicated in diverse processes from occlusion body maturation to nuclear stability and lysis. However, studies have also shown that it is non-essential for virus replication, at least in cell culture. Here, we describe the use of serial block-face scanning electron microscopy to achieve high-resolution 3D characterisation of P10 structures within Trichoplusia ni TN-368 cells infected with Autographa californica multiple nucleopolyhedrovirus. This has enabled unparalleled visualisation of P10 and determined the independent formation of dynamic perinuclear and nuclear vermiform fibrous structures. Our 3D data confirm the sequence of ultrastructural changes that create a perinuclear cage from thin angular fibrils within the cytoplasm. Over the course of infection in cultured cells, the cage remodels to form a large polarised P10 mass and we suggest that these changes are critical for nuclear lysis to release occlusion bodies. In contrast, nuclear P10 forms a discrete vermiform structure that was observed in close spatial association with both electron dense spacers and occlusion bodies; supporting a previously suggested role for P10 and electron dense spacers in the maturation of occlusion bodies. We also demonstrate that P10 hyper-expression is critical for function. Decreasing levels of p10 expression, achieved by manipulation of promoter length, correlated with reduced P10 production, a lack of formation of P10 structures and a concomitant decrease in nuclear lysis. [ABSTRACT FROM AUTHOR]

This study collected 183 Hemerocallis varieties to conduct numerical classification of flower color and provide valuable baseline data and foundational theory for normalization and precision of Hemerocallis. The color CIELab phenotypes were collected via colorimeter (CR-10 Plus), which separately measured three sepal and petal parts (throat, eye and limb). The colors of experimental samples were artificially named by the Royal Horticultural Society Colour Chart (RHSCC). All the data were analyzed using R software. The results showed that the throat was predominantly green-yellow, light yellow and yellow; green-yellow accounted for the largest proportion of sepals (67.76%) and petals (69.40%). The eye was more abundant, and there were significant differences between sepals and petals. The limb was clustered into five color groups (orange, yellow, pink, red and purple); the yellow group had the most varieties for both sepals and petals, containing 57.38% and 55.74%, respectively. Both sepals and petals had significant differences (p<0.0001) in color (△E), redness (a*) and color angle (h) for the throat, eye and limb. However, the difference in CIELab phenotypes between the eye and limb were not significant. According to "Dual Classification", the color classification standard was proposed as a 3-level standard. The color of sepal and petal consistency served as the first standard, and the color of limb was the second standard. The color pattern types of pure, gradual change, watermark and eye spot, served as the third standard. It has been proposed that all the 183 experimental varieties were divided into two categories, five groups and finally four types. This study provides a classification basis and reference for numeric and standardized color phenotype description for Hemerocallis. [ABSTRACT FROM AUTHOR]

N6-Methyladenosine (m6A) RNA methylation plays important roles during development in different species. However, knowledge of m6A RNA methylation in monocots remains limited. In this study, we reported that OsFIP and OsMTA2 are the components of m6A RNA methyltransferase complex in rice and uncovered a previously unknown function of m6A RNA methylation in regulation of plant sporogenesis. Importantly, OsFIP is essential for rice male gametogenesis. Knocking out of OsFIP results in early degeneration of microspores at the vacuolated pollen stage and simultaneously causes abnormal meiosis in prophase I. We further analyzed the profile of rice m6A modification during sporogenesis in both WT and OsFIP loss-of-function plants, and identified a rice panicle specific m6A modification motif “UGWAMH”. Interestingly, we found that OsFIP directly mediates the m6A methylation of a set of threonine protease and NTPase mRNAs and is essential for their expression and/or splicing, which in turn regulates the progress of sporogenesis. Our findings revealed for the first time that OsFIP plays an indispensable role in plant early sporogenesis. This study also provides evidence for the different functions of the m6A RNA methyltransferase complex between rice and Arabidopsis. [ABSTRACT FROM AUTHOR]

During early meiotic prophase, homologous chromosomes are connected along their entire lengths by a proteinaceous tripartite structure known as the synaptonemal complex (SC). Although the components that comprise the SC are predominantly studied in this canonical ribbon-like structure, they can also polymerize into repeated structures known as polycomplexes. We find that in Drosophila oocytes, the ability of SC components to assemble into canonical tripartite SC requires the E3 ubiquitin ligase Seven in absentia (Sina). In sina mutant oocytes, SC components assemble into large rod-like polycomplexes instead of proper SC. Thus, the wild-type Sina protein inhibits the polymerization of SC components, including those of the lateral element, into polycomplexes. These polycomplexes persist into meiotic stages when canonical SC has been disassembled, indicating that Sina also plays a role in controlling SC disassembly. Polycomplexes induced by loss-of-function sina mutations associate with centromeres, sites of double-strand breaks, and cohesins. Perhaps as a consequence of these associations, centromere clustering is defective and crossing over is reduced. These results suggest that while features of the polycomplexes can be recognized as SC by other components of the meiotic nucleus, polycomplexes nonetheless fail to execute core functions of canonical SC. [ABSTRACT FROM AUTHOR]

Electrical synapses between neurons, also known as gap junctions, are direct cell membrane channels between adjacent neurons. Gap junctions play a role in the synchronization of neuronal network activity; however, their involvement in cognition has not been well characterized. Three-hour olfactory associative memory in Drosophila has two components: consolidated anesthesia-resistant memory (ARM) and labile anesthesia-sensitive memory (ASM). Here, we show that knockdown of the gap junction gene innexin5 (inx5) in mushroom body (MB) neurons disrupted ARM, while leaving ASM intact. Whole-mount brain immunohistochemistry indicated that INX5 protein was preferentially expressed in the somas, calyxes, and lobes regions of the MB neurons. Adult-stage-specific knockdown of inx5 in αβ neurons disrupted ARM, suggesting a specific requirement of INX5 in αβ neurons for ARM formation. Hyperpolarization of αβ neurons during memory retrieval by expressing an engineered halorhodopsin (eNpHR) also disrupted ARM. Administration of the gap junction blocker carbenoxolone (CBX) reduced the proportion of odor responsive αβ neurons to the training odor 3 hours after training. Finally, the α-branch-specific 3-hour ARM-specific memory trace was also diminished with CBX treatment and in inx5 knockdown flies. Altogether, our results suggest INX5 gap junction channels in αβ neurons for ARM retrieval and also provide a more detailed neuronal mechanism for consolidated memory in Drosophila. [ABSTRACT FROM AUTHOR]

Given the disposability of somatic tissue, selection can favor a higher mutation rate in the early segregating soma than in germline, as seen in some animals. Although in plants intra-organismic mutation rate heterogeneity is poorly resolved, the same selectionist logic can predict a lower rate in shoot than in root and in longer-lived terminal tissues (e.g., leaves) than in ontogenetically similar short-lived ones (e.g., petals), and that mutation rate heterogeneity should be deterministic with no significant differences between biological replicates. To address these expectations, we sequenced 754 genomes from various tissues of eight plant species. Consistent with a selectionist model, the rate of mutation accumulation per unit time in shoot apical meristem is lower than that in root apical tissues in perennials, in which a high proportion of mutations in shoots are themselves transmissible, but not in annuals, in which somatic mutations tend not to be transmissible. Similarly, the number of mutations accumulated in leaves is commonly lower than that within a petal of the same plant, and there is no more heterogeneity in accumulation rates between replicate branches than expected by chance. High mutation accumulation in runners of strawberry is, we argue, the exception that proves the rule, as mutation transmission patterns indicate that runner has a restricted germline. However, we also find that in vitro callus tissue has a higher mutation rate (per unit time) than the wild-grown comparator, suggesting nonadaptive mutational “fragility”. As mutational fragility does not obviously explain why the shoot—root difference varies with plant longevity, we conclude that some mutation rate variation between tissues is consistent with selectionist theory but that a mechanistic null of mutational fragility should be considered. [ABSTRACT FROM AUTHOR]

Tissue morphogenesis critically depends on the coordination of cellular growth patterns. In plants, many organs consist of clonally distinct cell layers, such as the epidermis, whose cells undergo divisions that are oriented along the plane of the layer. The developmental control of such planar growth is poorly understood. We have previously identified the Arabidopsis AGCVIII-class protein kinase UNICORN (UCN) as a central regulator of this process. Plants lacking UCN activity show spontaneous formation of ectopic multicellular protrusions in integuments and malformed petals indicating that UCN suppresses uncontrolled growth in those tissues. In the current model UCN regulates planar growth of integuments in part by directly repressing the putative transcription factor ABERRANT TESTA SHAPE (ATS). Here we report on the identification of 3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE 1 (PDK1) as a novel factor involved in UCN-mediated growth control. PDK1 constitutes a basic component of signaling mediated by AGC protein kinases throughout eukaryotes. Arabidopsis PDK1 is implied in stress responses and growth promotion. Here we show that loss-of-function mutations in PDK1 suppress aberrant growth in integuments and petals of ucn mutants. Additional genetic, in vitro, and cell biological data support the view that UCN functions by repressing PDK1. Furthermore, our data indicate that PDK1 is indirectly required for deregulated growth caused by ATS overexpression. Our findings support a model proposing that UCN suppresses ectopic growth in integuments through two independent processes: the attenuation of the protein kinase PDK1 in the cytoplasm and the repression of the transcription factor ATS in the nucleus. [ABSTRACT FROM AUTHOR]

Corolla color in Gentiana lutea L. exhibits a yellow/orange variation. We previously demonstrated that the orange petal color of G. lutea L. var. aurantiaca is predominantly caused by newly synthesized pelargonidin glycosides that confer a reddish hue to the yellow background color, derived from the carotenoids. However, the anthocyanin molecules of these pelargonidin glycosides are not yet fully identified and characterized. Here, we investigated the regulation, content and type of anthocyanins determining the petal coloration of the orange-flowered G. lutea L. var. aurantiaca. Anthocyanins from the petals of G. lutea L. var. aurantiaca were characterized and quantified by HPLC-ESI-MS/MS (High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry) coupled with a diode array detector in flowers at three different stages of development (S1, S3 and S5). Eleven pelargonidin derivatives were identified in the petals of G. lutea L. var. aurantiaca for the first time, but quantitative and qualitative differences were observed at each developmental stage. The highest levels of these pelargonidin derivatives were reached at the fully open flower stage (S5) where all anthocyanins were detected. In contrast, not all the anthocyanins were detected at the budlet stage (S1) and mature bud stage (S3) and those corresponded to more complex pelargonidin derivatives. The major pelargonidin derivatives found at all the stages were pelargonidin 3-O-glucoside, pelargonidin 3,5-O-diglucoside and pelargonidin 3-O-rutinoside. Furthermore, the expression of DFR (dihydroflavonol 4-reductase), ANS (anthocyanidin synthase), 3GT (UDP-glucose:flavonoid 3-O-glucosyltransferase), 5GT (UDP-glucose:flavonoid 5-O-glucosyltransferase) and 5AT (anthocyanin 5-aromatic acyltransferase) genes was analyzed in the petals of three developmental stages, showing that the expression level of DFR, ANS and 3GT parallels the accumulation of the pelargonidin glucosides. Overall, this study enhances the knowledge of the biochemical basis of flower coloration in Gentiana species, and lays a foundation for breeding of flower color and genetic variation studies on Gentiana varieties. [ABSTRACT FROM AUTHOR]

Floral bilateral symmetry is one of the most important acquisitions in flower shape evolution in angiosperms. Members of Gesneriaceae possess predominantly zygomorphic flowers yet natural reversal to actinomorphy have independently evolved multiple times. The development of floral bilateral symmetry relies greatly on the gene CYCLOIDEA (CYC). Our reconstructed GCYC phylogeny indicated at least five GCYC duplication events occurred over the evolutionary history of Gesneriaceae. However, the patterns of GCYC expression following the duplications and the role of natural selection on GCYC copies in relation to floral symmetry remained largely unstudied. The Asiatic tribe Trichosporeae contains most reversals to actinomorphy. We thus investigated shifts in GCYC gene expression among selected zygomorphic species (Hemiboea bicornuta and Lysionotus pauciflorus) and species with reversals to actinomorphy (Conandron ramondioides) by RT-PCR. In the actinomorphic C. ramondioides, none of the three copies of GCYC was found expressed in petals implying that the reversal was a loss-of-function event. On the other hand, both zygomorphic species retained one GCYC1 copy that was expressed in the dorsal petals but each species utilized a different copy (GCYC1C for H. bicornuta and GCYC1D for L. pauciflorus). Together with previously published data, it appeared that GCYC1C and GCYC1D copies diversified their expression in a distinct species-specific pattern. To detect whether the selection signal (ω) changed before and after the duplication of GCYC1 in Asiatic Trichosporeae, we reconstructed a GCYC phylogeny using maximum likelihood and Bayesian inference algorithms and examined selection signals using PAML. The PAML analysis detected relaxation from selection right after the GCYC1 duplication (ωpre-duplication = 0.2819, ωpost-duplication = 0.3985) among Asiatic Trichosporeae species. We propose that the selection relaxation after the GCYC1 duplication created an "evolutionary window of flexibility" in which multiple copies were retained with randomly diverged roles for dorsal-specific expressions in association with floral symmetry changes. [ABSTRACT FROM AUTHOR]

Four new species of Capsicum (Capsiceae, Solanaceae) from Andean tropical forests in South America are described. Capsicum benoistii Hunz. ex Barboza sp. nov. (incertae sedis) is endemic to a restricted area in south-central Ecuador and is most similar to the more widespread C. geminifolium (Dammer) Hunz. (Colombia, Ecuador, and Peru). Capsicum piuranum Barboza & S. Leiva sp. nov. (Andean clade) is found in northern Peru (Department Piura) and is morphologically most similar to C. caballeroi M. Nee of the Bolivian yungas (Departments Santa Cruz and Cochabamba) but closely related to C. geminifolium and C. lycianthoides Bitter. Capsicum longifolium Barboza & S. Leiva sp. nov. (Andean clade) occurs from northern Peru (Departments Amazonas, Cajamarca, and Piura) to southern Ecuador (Province Zamora-Chinchipe), and is morphologically most similar to C. dimorphum (Miers) Kuntze (Colombia, Ecuador, and Peru). Capsicum neei Barboza & X. Reyes sp. nov. (Bolivian clade) is endemic to southeastern Bolivia (Departments Chuquisaca and Santa Cruz) in the Boliviano-Tucumano Forest, is morphologically most similar to another Bolivian endemic species C. minutiflorum Rusby (Hunz.), and is closely related to C. caballeroi. Complete descriptions, illustrations, distributions and conservation assessments of all new species are given. Chromosome numbers for C. piuranum and C. longifolium are also provided. Three of the new species were included in a new phylogenetic analysis for Capsicum; their positions were strongly resolved within clades previously recognized in the genus. [ABSTRACT FROM AUTHOR]

The release of neurotransmitters from synapses obeys complex and stochastic dynamics. Depending on the recent history of synaptic activation, many synapses depress the probability of releasing more neurotransmitter, which is known as synaptic depression. Our understanding of how synaptic depression affects the information efficacy, however, is limited. Here we propose a mathematically tractable model of both synchronous spike-evoked release and asynchronous release that permits us to quantify the information conveyed by a synapse. The model transits between discrete states of a communication channel, with the present state depending on many past time steps, emulating the gradual depression and exponential recovery of the synapse. Asynchronous and spontaneous releases play a critical role in shaping the information efficacy of the synapse. We prove that depression can enhance both the information rate and the information rate per unit energy expended, provided that synchronous spike-evoked release depresses less (or recovers faster) than asynchronous release. Furthermore, we explore the theoretical implications of short-term synaptic depression adapting on longer time scales, as part of the phenomenon of metaplasticity. In particular, we show that a synapse can adjust its energy expenditure by changing the dynamics of short-term synaptic depression without affecting the net information conveyed by each successful release. Moreover, the optimal input spike rate is independent of the amplitude or time constant of synaptic depression. We analyze the information efficacy of three types of synapses for which the short-term dynamics of both synchronous and asynchronous release have been experimentally measured. In hippocampal autaptic synapses, the persistence of asynchronous release during depression cannot compensate for the reduction of synchronous release, so that the rate of information transmission declines with synaptic depression. In the calyx of Held, the information rate per release remains constant despite large variations in the measured asynchronous release rate. Lastly, we show that dopamine, by controlling asynchronous release in corticostriatal synapses, increases the synaptic information efficacy in nucleus accumbens. [ABSTRACT FROM AUTHOR]

Thousand grain weight is one of the components determining wheat grain yield. It represents the average value of individual grain weights which depends on position within the ear and on positon within the spikelet. Our objective was to quantify the influences of individual floret anthesis date, of carpel weight at anthesis and of rate and duration of grain filling, on variation in individual final grain weight. Two bread wheat cultivars were grown in a greenhouse and their ears were sampled from anthesis through to harvest. Each ear was divided into three parts—basal, central and apical—where the two proximal grains were dissected from each of two spikelets. We analysed (i) the flowering time shift within the ear and within the spikelet; and (ii) the growth kinetics during grain filling in relation to position along the ear. For both cultivars, florets located in the central part of the ear were the first to reach anthesis followed by those in the apical part and then the basal part. Within a spikelet, the floret located nearest the rachis flowered first followed by the more distal ones. We found no significant systematic effect of flowering time-shift on final grain weight. Nevertheless, grains in the central part were heavier than the basal ones (9.75% smaller) and than the apical ones (18.25% smaller). These differences were explained mainly by differences in mean grain filling rates. Analysis of growth kinetics enabled an improved explanation of the variability of individual grain weight along the ear. [ABSTRACT FROM AUTHOR]

Background and aims: The bacterial leaf nodule symbiosis is a close interaction between endophytes and their plant hosts, mainly within the coffee family. The interaction between Rubiaceae species and Burkholderia bacteria is unique due to its obligate nature, high specificity, and predominantly vertical transmission of the endophytes to the next generation of host plants. This vertical transmission is intriguing since it is the basis for the uniqueness of the symbiosis. However, unequivocal evidence of the location of the endophytes in the seeds is lacking. The aim of this paper is therefore to demonstrate the presence of the host specific endophyte in the seeds of Psychotria punctata and confirm its precise location. In addition, the suggested location of the endophyte in other parts of the host plant is investigated. Methods: To identify and locate the endophyte in Psychotria punctata, a two-level approach was adopted using both a molecular screening method and fluorescent in situ hybridisation microscopy. Key results: The endophytes, molecularly identified as Candidatus Burkholderia kirkii, were detected in the leaves, vegetative and flower buds, anthers, gynoecium, embryos, and young twigs. In addition, they were in situ localised in leaves, flowers and shoot apical meristems, and, for the first time, in between the cotyledons of the embryos. Conclusions: Both independent techniques detected the host specific endophyte in close proximity to the shoot apical meristem of the embryo, which confirms for the first time the exact location of the endophytes in the seeds. This study provides reliable proof that the endophytes are maintained throughout the growth and development of the host plant and are transmitted vertically to the offspring. [ABSTRACT FROM AUTHOR]

The Rubiaceae tribe Rubieae has a world-wide distribution with up to 1,000 species. These collectively exhibit an enormous ecological and morphological diversity, making Rubieae an excellent group for macro- and microevolutionary studies. Previous molecular phylogenetic analyses used only a limited sampling within the tribe or missed lineages crucial for understanding character evolution in this group. Here, we analyze sequences from two plastid spacer regions as well as morphological and biogeographic data from an extensive and evenly distributed sampling to establish a sound phylogenetic framework. This framework serves as a basis for our investigation of the evolution of important morphological characters and the biogeographic history of the Rubieae. The tribe includes three major clades, the Kelloggiinae Clade (Kelloggia), the Rubiinae Clade (Didymaea, Rubia) and the most species-rich Galiinae Clade (Asperula, Callipeltis, Crucianella, Cruciata, Galium, Mericarpaea, Phuopsis, Sherardia, Valantia). Within the Galiinae Clade, the largest genera Galium and Asperula are para- and polyphyletic, respectively. Smaller clades, however, usually correspond to currently recognized taxa (small genera or sections within genera), which may be used as starting points for a refined classification in this clade. Life-form (perennial versus annual), flower shape (long versus short corolla tube) and fruit characters (dry versus fleshy, with or without uncinate hairs) are highly homoplasious and have changed multiple times independently. Inference on the evolution of leaf whorls, a characteristic feature of the tribe, is sensitive to model choice. Multi-parted leaf whorls appear to have originated from opposite leaves with two small interpetiolar stipules that are subsequently enlarged and increased in number. Early diversification of Rubieae probably started during the Miocene in western Eurasia. Disjunctions between the Old and the New World possibly are due to connections via a North Atlantic land bridge. Diversification of the Galiineae Clade started later in the Miocene, probably in the Mediterranean, from where lineages reached, often multiple times, Africa, eastern Asia and further on the Americas and Australia. [ABSTRACT FROM AUTHOR]

Meiotic cytokinesis influences the fertility and ploidy of gametes. However, limited information is available on the genetic control of meiotic cytokinesis in plants. Here, we identified a rice mutant with low male fertility, defective callose in meiosis 1 (dcm1). The pollen grains of dcm1 are proved to be defective in exine formation. Meiotic cytokinesis is disrupted in dcm1, resulting in disordered spindle orientation during meiosis II and formation of pollen grains with varied size and DNA content. We demonstrated that meiotic cytokinesis defect in dcm1 is caused by prematurely dissolution of callosic plates. Furthermore, peripheral callose surrounding the dcm1 pollen mother cells (PMCs) also disappeared untimely around pachytene. The DCM1 protein contains five tandem CCCH motifs and interacts with nuclear poly (A) binding proteins (PABNs) in nuclear speckles. The expression profiles of genes related to callose synthesis and degradation are significantly modified in dcm1. Together, we propose that DCM1 plays an essential role in male meiotic cytokinesis by preserving callose from prematurely dissolution in rice. [ABSTRACT FROM AUTHOR]

Summary: In Arabidopsis thaliana the CLAVATA1 (CLV1) receptor and GENERAL CONTROL NON DEREPRESSIBLE 5 (GCN5) histone acetyltransferase both regulate inflorescence meristem size and affect the expression of the meristem‐promoting transcription factor WUSCHEL (WUS). Single and multiple mutants of GCN5 and CLAVATA members, were analysed for their gynoecium development, using morphological, physiological, genetic and molecular approaches. The clv1‐1gcn5‐1 double mutants exhibited novel phenotypes including elongated gynoecia with reduced valves and enlarged stigma and style, indicating a synergistic action of CLAVATA signaling and GCN5 action in the development of the gynoecium. Reporter line and gene expression analysis showed that clv1‐1gcn5‐1 plants have altered auxin and cytokinin response, distribution and ectopic overexpression of WUS. WUS expression was found in the style of wild‐type gynoecia stage 10–13, suggesting a possible novel role for WUS in the development of the style. CLV1 and GCN5 are regulators of apical–basal and mediolateral polarity of the Arabidopsis gynoecium. They affect gynoecium morphogenesis through the negative regulation of auxin biosynthesis and promotion of polar auxin transport. They also promote cytokinin signaling in the carpel margin meristem and negatively regulate it at the stigma. Finally, they synergistically suppress WUS at the centre of the gynoecium. [ABSTRACT FROM AUTHOR]

Morphological classification of living things has challenged science for several centuries and has led to a wide range of objective morphometric approaches in data gathering and analysis. In this paper we explore those methods using apple cultivars, a model biological system in which discrete groups are pre-defined but in which there is a high level of overall morphological similarity. The effectiveness of morphometric techniques in discovering the groups is evaluated using statistical learning tools. No one technique proved optimal in classification on every occasion, linear morphometric techniques slightly out-performing geometric (72.6% accuracy on test set versus 66.7%). The combined use of these techniques with post-hoc knowledge of their individual successes with particular cultivars achieves a notably higher classification accuracy (77.8%). From this we conclude that even with pre-determined discrete categories, a range of approaches is needed where those categories are intrinsically similar to each other, and we raise the question of whether in studies where potentially continuous natural variation is being categorised the level of match between categories is routinely set too high. [ABSTRACT FROM AUTHOR]

Plants have evolved diverse cell types with distinct sizes, shapes, and functions. For example, most flowering plants contain specialized petal conical epidermal cells that are thought to attract pollinators and influence light capture and reflectance, but the molecular mechanisms controlling conical cell shaping remain unclear. Here, through a genetic screen in Arabidopsis thaliana, we demonstrated that loss-of-function mutations in ANGUSTIFOLIA (AN), which encodes for a homolog of mammalian CtBP/BARs, displayed conical cells phenotype with wider tip angles, correlating with increased accumulation of reactive oxygen species (ROS). We further showed that exogenously supplied ROS generated similar conical cell phenotypes as the an mutants. Moreover, reduced endogenous ROS levels resulted in deceased tip sharpening of conical cells. Furthermore, through enhancer screening, we demonstrated that mutations in katanin (KTN1) enhanced conical cell phenotypes of the an-t1 mutants. Genetic analyses showed that AN acted in parallel with KTN1 to control conical cell shaping. Both increased or decreased ROS levels and mutations in AN suppressed microtubule organization into well-ordered circumferential arrays. We demonstrated that the AN-ROS pathway jointly functioned with KTN1 to modulate microtubule ordering, correlating with the tip sharpening of conical cells. Collectively, our findings revealed a mechanistic insight into ROS homeostasis regulation of microtubule organization and conical cell shaping. [ABSTRACT FROM AUTHOR]

INDUCER OF CBF EXPRESSION 1 (ICE1) encodes a MYC-like basic helix-loop-helix (bHLH) transcription factor playing a critical role in plant responses to chilling and freezing stresses and leaf stomata development. However, no information connecting ICE1 and reproductive development has been reported. In this study, we show that ICE1 controls plant male fertility via impacting anther dehydration. The loss-of-function mutation in ICE1 gene in Arabidopsis caused anther indehiscence and decreased pollen viability as well as germination rate. Further analysis revealed that the anthers in the mutant of ICE1 (ice1-2) had the structure of stomium, though the epidermis did not shrink to dehisce. The anther indehiscence and influenced pollen viability as well as germination in ice1-2 were due to abnormal anther dehydration, for most of anthers dehisced with drought treatment and pollen grains from those dehydrated anthers had similar viability and germination rates compared with wild type. Accordingly, the sterility of ice1-2 could be rescued by ambient dehydration treatments. Likewise, the stomatal differentiation of ice1-2 anther epidermis was disrupted in a different manner compared with that in leaves. ICE1 specifically bound to MYC-recognition elements in the promoter of FAMA, a key regulator of guard cell differentiation, to activate FAMA expression. Transcriptome profiling in the anther tissues further exhibited ICE1-modulated genes associated with water transport and ion exchange in the anther. Together, this work reveals the key role of ICE1 in male fertility control and establishes a regulatory network mediated by ICE1 for stomata development and water movement in the anther. [ABSTRACT FROM AUTHOR]