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Megan J Colwell, Geoffrey R Williams, Rodger C Evans, Dave Shutler
European honey bees Apis mellifera are important commercial pollinators that have suffered greater than normal overwintering losses since 2007 in North America and Europe. Contributing factors likely include a combination of parasites, pesticides, and poor nutrition. We examined diet diversity, diet nutritional quality, and pesticides in honey bee-collected pollen from commercial colonies in the Canadian Maritime Provinces in spring and summer 2011. We sampled pollen collected by honey bees at colonies in four site types: apple orchards, blueberry fields, cranberry bogs, and fallow fields...
September 2017: Ecology and Evolution
Ana Lázaro-Nogal, Silvia Matesanz, Alfredo García-Fernández, Anna Traveset, Fernando Valladares
The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species' distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs...
September 2017: Ecology and Evolution
Giuseppe Pellegrino, Francesca Bellusci, Anna Maria Palermo
Floral displays, influencing attractiveness to insects, increase the number of pollinator visits and the efficiency of each visit in terms of pollen exchange and thus affect the plant reproductive success. Here, we conducted an in situ manipulation experiment to investigate whether the floral modifications affect reproductive success in natural orchid populations of Serapias lingua and Serapias vomeracea. We estimated male and female reproductive success of three treatment groups, disassembly of floral tube, cutting of lip, and painting of the callus surface, in terms of pollinaria removed/deposited and fruit production...
September 2017: Ecology and Evolution
Yinghong Lu, Sandra Stegemann, Shreya Agrawal, Daniel Karcher, Stephanie Ruf, Ralph Bock
Transgene expression from the plastid (chloroplast) genome provides unique advantages, including high levels of foreign protein accumulation, convenient transgene stacking in operons, and increased biosafety due to exclusion of plastids from pollen transmission [1, 2]. However, applications in biotechnology and synthetic biology are severely restricted by the very small number of plant species whose plastid genomes currently can be transformed [3, 4]. Here we report a simple method for the introduction of useful plastid transgenes into non-transformable species...
September 16, 2017: Current Biology: CB
Yosuke Matsushita, Hironobu Yanagisawa
Vertical and horizontal pollen transmission is important for efficient infection by viroids. Vertical pollen transmission of viroids is attributed to the infection by viroid in the embryo sac through infected pollen. To identify the viroid infection in pollen and pollen tubes elongating through the transmitting tract, we used in situ hybridization to histochemically analyze the distribution of Tomato planta macho viroid (TPMVd) in pollen grains, the stigma, and style of petunia plants. TPMVd was present in the generative nucleus and vegetative nucleus of mature infected pollen grains and germinating pollen grains...
September 23, 2017: Virus Genes
Yue Lou, Hai-Sheng Zhou, Yu Han, Qiu-Ye Zeng, Jun Zhu, Zhong-Nan Yang
Tapetum development and pollen production are regulated by a complex transcriptional network that consists of a group of tapetum-specific Arabidopsis transcription factors (TFs). Among these TFs, DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION 1 (TDF1) encodes an R2R3 MYB factor, and ABORTED MICROSPORE (AMS) encodes a basic helix-loop-helix (bHLH) factor. However, knowledge regarding the regulatory role of TDF1 in anther development remains limited. Here, we discovered that TDF1 directly regulates AMS via an AACCT cis-element...
September 20, 2017: New Phytologist
O Gavrilova, N Zavialova, M Tekleva, E Karasev
We have tested possibilities and limitations of confocal laser scanning microscopy to study the morphology of pollen and spores and inner structure of sporoderms. As test objects, we used pollen grains of the modern angiosperm Ribes niveum (Grossulariaceae) and Datura metel (Solanaceae), fossil angiosperm pollen grains of Pseudointegricorpus clarireticulatum and Wodehouseia spinata dated to the Late Cretaceous, fossil gymnosperm pollen grains of Cycadopites-type dated to the Middle Jurassic, and fossil megaspores Maexisporites rugulaeferus, M...
September 21, 2017: Journal of Microscopy
Patrick Duckney, Michael J Deeks, Martin R Dixon, Johan Kroon, Timothy J Hawkins, Patrick J Hussey
During fertilization, Pollen Receptor-Like Kinases (PRKs) control pollen tube growth through the pistil in response to extracellular signals, and regulate the actin cytoskeleton at the tube apex to drive tip growth. We investigated a novel link between membrane-integral PRKs and the actin cytoskeleton, mediated through interactions between PRKs and NET2A; a pollen-specific member of the NETWORKED superfamily of actin-binding proteins. We characterize NET2A as a novel actin-associated protein that localizes to punctae at the plasma membrane of the pollen tube shank, which are stably associated with cortical longitudinal actin cables...
September 20, 2017: New Phytologist
Sunil Kumar Singh, Vajinder Kumar Kumar, Ramamurthy Srinivasan, Paramvir Singh Ahuja, Shripad Ramchandra Bhat, Yelam Sreenivasulu
In plants, the role of TRAF-like proteins with meprin and the TRAF homology (MATH) domain is far from clear. In animals, these proteins serve as adapter molecules to mediate signal transduction from TNF-R to downstream effector molecules. A seed-sterile mutant with disrupted TRAF-like gene (At5g26290) exhibiting aberrant gametogenesis led us to investigate the developmental role of this gene in Arabidopsis. The mutation was semi-dominant and resulted in pleiotropic phenotypes with such features as short siliques with fewer ovules, pollen and seed sterility, altered MMC specification, and delayed programmed cell death in megaspores and the tapetum-features that overlapped those in other well-characterized mutants...
September 22, 2017: Plant Physiology
Seςil Kepil Özdemir, Selcan Özgüςlü
BACKGROUND: There is limited data regarding pollen food allergy syndrome (PFAS) in Turkey. OBJECTIVES: To investigate the clinical characteristics and possible risk factors of PFAS in Turkey, and to evaluate if there was an association between skin test reactivity to pollens and presence of PFAS. METHODS: A total of 254 consecutive adult patients with pollen sensitivity were prospectively recruited. Patients were interviewed with a questionnaire including a list of pollen-associated foods...
September 17, 2017: Asian Pacific Journal of Allergy and Immunology
Jaroslav Klápště, Mari Suontama, Emily Telfer, Natalie Graham, Charlie Low, Toby Stovold, Russel McKinley, Heidi Dungey
Accurate inference of relatedness between individuals in breeding population contributes to the precision of genetic parameter estimates, effectiveness of inbreeding management and the amount of genetic progress delivered from breeding programs. Pedigree reconstruction has been proven to be an efficient tool to correct pedigree errors and recover hidden relatedness in open pollinated progeny tests but the method can be limited by the lack of parental genotypes and the high proportion of alien pollen from outside the breeding population...
2017: PloS One
Akari Shibata, Yoshiaki Kameyama, Gaku Kudo
Gynodioecy is the coexistence of hermaphrodites and females in a population. It is supposed to be an intermediate stage in the evolutionary pathway from hermaphroditism to dioecy in angiosperm. Hermaphrodites gain fitness through both seed and pollen production whereas females gain fitness only through seed production. As females spread in a gynodioecious population, sexual selection prompts hermaphrodites to invest in male function and male-biased hermaphrodites prevail. In the gynodioecious shrub Daphne jezoensis (Thymelaeaceae), female frequency is stably around 50% in most populations, and fruit-set rate of hermaphrodites is commonly low...
September 21, 2017: Journal of Plant Research
Iris Heidmann, Marco Di Berardino
Analyzing pollen quality in an efficient and reliable manner is of great importance to the industries involved in seed and fruit production, plant breeding, and plant research. Pollen quality parameters, viability and germination capacity, are analyzed by various staining methods or by in vitro germination assays, respectively. These methods are time-consuming, species-dependent, and require a lab environment. Furthermore, the obtained viability data are often poorly related to in vivo pollen germination and seed set...
2017: Methods in Molecular Biology
Benjamin Peters, Jack Aidley, Murray Cadzow, David Twell, Lynette Brownfield
The male germline of flowering plants develops within the vegetative cell of the male gametophyte and displays a distinct transcriptional profile. Key to understanding the development of this unique cell lineage is determining how gene expression is regulated within germline cells. This knowledge impacts upon our understanding of cell specification, differentiation, and plant fertility. Here, we describe methods to identify cis-regulatory modules (CRMs) that act as key regulatory regions in the promoters of germline-expressed genes...
2017: Methods in Molecular Biology
Jan Fíla, David Honys
Protein phosphorylation was repeatedly shown to be the most dynamic post-translational modification mediated by a huge orchestra of protein kinases and phosphatases. Upon landing on a stigma, pollen grain dehydration and activation are accompanied by changes in protein phosphorylation together with the translation activation of stored mRNAs. To enable studies of the total phosphoproteome, it is usually necessary to apply various enrichment techniques. In this chapter, one of these protocols that worked previously well on tobacco mature pollen is presented in more detail...
2017: Methods in Molecular Biology
German Martinez
In the last decade, the accumulation and roles of small RNAs have been slowly uncovered. Recently, the RNA silencing pathways active in the male gametophyte of plants have started to be analyzed in depth. Although several studies have shed light on the small RNA populations present in the pollen, we still lack a clear picture of their regulatory activity. This chapter outlines an extraction method of mature pollen grains and its different downstream applications for the purification and detection of small RNAs...
2017: Methods in Molecular Biology
Scott D Russell, Daniel S Jones, Sarah Anderson, Xinkun Wang, Venkatesan Sundaresan, Xiaoping Gou
The male germline of flowering plants displays unexpectedly divergent transcriptional profiles compared to other cell types and tissues of plants. As these are among the smallest cells, and are harbored within pollen, isolating a pure collection of germline RNA presents unusual challenges. The sperm cells of rice represent a particularly challenging subject for study as the pollen are unusually short lived upon release from the anther, and the marker gene sequences that make FACS possible in Arabidopsis have not yet been introduced into rice...
2017: Methods in Molecular Biology
Mário R Santos, Cláudia Bispo, Jörg D Becker
Efficient methods to isolate highly purified Arabidopsis thaliana pollen and the subcellular components of the male gametophyte (the vegetative nucleus and two sperm cells) have enabled genome-scale studies revealing a highly dynamic reprogramming of the transcriptome and epigenome during pollen development. Here, we describe the isolation of uninucleate microspores, mature pollen, as well as sperm cells and vegetative nuclei by Fluorescence-Activated Cell Sorting.
2017: Methods in Molecular Biology
Peng-Fei Jia, Hong-Ju Li, Wei-Cai Yang
Here, we describe methods of transmission electron microscopy (TEM) based on conventional chemical fixation and high-pressure freezing (HPF) and freeze-substitution (FS) to examine the ultrastructure of Arabidopsis pollen grains and pollen tubes. Compared to other plant samples, such as root or leaf, pollen grains have thick pollen coat and cell wall which limit the permeation of fixative. Thus, it is difficult to obtain high-quality ultrastructural images of pollen. Moreover, pollen tube is very soft and the traditional procedure is too harsh to get an intact pollen tube sample...
2017: Methods in Molecular Biology
Peng-Fei Jia, Hong-Ju Li, Wei-Cai Yang
Peroxisome is an essential single-membrane bound organelle in most eukaryotic cells and functions in diverse cellular processes. De novo formation, division, and turnover of peroxisomes contribute to its biogenesis, morphology, and population regulation. In plants, peroxisome plays multiple roles, including metabolism, development, and stress response. Defective peroxisome biogenesis and development retard plant growth, adaption, and reproduction. Through tracing the subcellular localization of fluorescent reporter tagged matrix protein of peroxisome, fluorescence microscopy is a reliable and fast way to detect peroxisome biogenesis...
2017: Methods in Molecular Biology
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