Plants, fungi, and freeloaders: examining temporal changes in the “taxonomic richness” of endophytic fungi in the dwarf mistletoe Arceuthobium americanum over its growing season

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 323-335 ◽  
Author(s):  
Lucas D. Hampel ◽  
Naowarat Cheeptham ◽  
Nancy J. Flood ◽  
Cynthia Ross Friedman

Arceuthobium americanum Nutt. ex Engelm. (lodgepole pine dwarf mistletoe) is a dioecious plant parasitizing conifers in North America. Here, we documented changes in the “taxonomic richness” of culturable endophytic fungi in male and female A. americanum over the growing season. Endophytic fungi were isolated from vegetative stems of surface-sterilized aerial shoots from male and female A. americanum collected weekly from April to September. Isolated fungi were characterized macroscopically, generating a database of 48 morphologically unique forms that likely represented individual taxa. A random sample of endophytic fungi was sequenced to determine identity based on ITS rDNA. Richness increased throughout the growing season similarly in the stems of both sexes, suggesting that increased developmental age or time in the environment facilitates an increase in endophyte richness: male and female endophyte communities were 91% similar based on Sorensen’s coefficient. Sequenced endophytes came from many diverse taxa, including Serpula, Alternaria, and Tremella, which may function as mutualistic symbionts within the mistletoe. An increase in fungal richness throughout the growing season has been observed in all flowering plants examined to date, although our observation is the first for the genus and for parasitic plants in general, and has also contributed to knowledge of fungal diversity in dioecious plants.

Author(s):  
Maria Fitzgerald ◽  
Michael W. Salter

The influence of development and sex on pain perception has long been recognized but only recently has it become clear that this is due to specific differences in underlying pain neurobiology. This chapter summarizes the evidence for mechanistic differences in male and female pain biology and for functional changes in pain pathways through infancy, adolescence, and adulthood. It describes how both developmental age and sex determine peripheral nociception, spinal and brainstem processing, brain networks, and neuroimmune pathways in pain. Finally, the chapter discusses emerging evidence for interactions between sex and development and the importance of sex in the short- and long-term effects of early life pain.


Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 178
Author(s):  
Matej Vosnjak ◽  
Matevz Likar ◽  
Gregor Osterc

The influence of mycorrhizal inoculum in combination with different phosphorus treatments on growth and flowering parameters of Ajania (Ajania pacifica (Nakai) Bremer et Humphries) plants was investigated in two growing seasons (2015 and 2016). Plants of the cultivar ‘Silver and Gold’ were transplanted into pots either with added mycorrhizal inoculum or without inoculum and assigned to four phosphorus treatments. Mycorrhizal colonization was assessed by evaluating the frequency of colonization, intensity of colonization and density of fungal structures (arbuscules, vesicles, coils and microsclerotia) in the roots. During the growing season, the content of plant available phosphorus in the soil was analyzed, and shoot length, number of shoots, number of inflorescences, number of flowers and flowering time were evaluated. Inoculated Ajania plants were successfully colonized with arbuscular mycorrhizal fungi and dark septate endophytic fungi. In the root segments, hyphae were mainly observed, as well as vesicles, coils, arbuscules and microsclerotia, but in lower density. The density of fungal structures did not differ among phosphorus treatments, but did differ between years, with a higher density of fungal structures in 2016. Mycorrhizal plants developed higher number of shoots in 2016, higher number of inflorescences, higher number of flowers, and they flowered longer compared to uninoculated plants.


1989 ◽  
Vol 44 (3-4) ◽  
pp. 226-232 ◽  
Author(s):  
Keiko Yanosaka ◽  
Hajime Iwamura ◽  
Toshio Fujita

Abstract A series of N-phenylcarbamates induced flowers in one-month-old seedlings of Asparagus officinalis L. Ninety to 100% of the plants flowered when the seeds were germinated in the presence of the most potent members of this class. The flowering occurred only once at the top of the seedlings, which then continued to grow normally. This made it possible to select the commer­cially preferred m ales of this dioecious plant at the seedling stage. Both male and female flowers were fertile, so cross-breeding was possible between flowering seedlings as well as between flowering seedlings and adults that had grown normally. Activity of flowering induction was not related with inhibition of photosystem II activity.


2019 ◽  
Vol 286 (1913) ◽  
pp. 20191805 ◽  
Author(s):  
Takashi Akagi ◽  
Deborah Charlesworth

One reason for studying sex chromosomes of flowering plants is that they have often evolved separate sexes recently, and the genomes of dioecious species may not yet have evolved adaptations to their changes from the ancestral state. An unstudied question concerns the relative importance of such adaptation, versus the effects of the mutations that led to separate sexes in the first place. Theoretical models for such an evolutionary change make the prediction that the mutations that created males must have sexually antagonistic effects, not only abolishing female functions, but also increasing male functions relative to the ancestral functional hermaphrodites. It is important to test this critical assumption. Moreover, the involvement of sexual antagonism also implies that plant sex-determining genes may directly cause some of the sexual dimorphisms observed in dioecious plants. Sex-determining genes are starting to be uncovered in plants, including species in the genera Diospyros and Actinidia (families Ebenaceae and Actinidiaceae, respectively). Here, we describe transgenic experiments in which the effects of the very different male-determining genes of these two dioecious species were studied in a non-dioecious plant, Nicotiana tabacum . The results indeed support the critical assumption outlined above.


2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.


2012 ◽  
Vol 21 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Lyssa L. Martin ◽  
Cynthia Ross Friedman ◽  
Ronald G. Smith

The lodgepole pine dwarf mistletoe Arceuthobium americanum is a severe pest in coniferous forests of western North America.  To facilitate laboratory studies of this obligate parasite, a modified White’s medium was used for in vitro culture; the concentrations of IAA and Kn were varied to determine optimal IAA/Kn ratios.  It was found that explant health was related to the concentration of IAA (p = 0.008), but not Kn (p = 0.937), and that explants were healthiest at an IAA/Kn ratio of 0.1.  Radicular apices were generated at IAA/Kn ratios of 1.0 or greater, but no shoot organogenesis was observed.  These data suggest that A. americanum is more sensitive to auxins than cytokinins.  Parasites of plants are known to secrete high levels of cytokinins, which stimulate the host to shuttle nutrients to the infected area, and so we suspect that A. americanum has reduced cytokinin sensitivity.   Key words: Callus culture, Arceuthobium americanum, Explant, Response, Cytokinin, Insensitivity   D.O.I. 10.3329/ptcb.v21i1.9557   Plant Tissue Cult. & Biotech. 21(1): 1-10, 2011 (June)


2003 ◽  
Vol 83 (2) ◽  
pp. 409-410 ◽  
Author(s):  
T. S. C. Li ◽  
D. Wardle

A study was conducted at Summerland, BC, in 2000 and 2001 to investigate the effect of harvest period on the protein content of sea buckthorn leaves. Leaves of both male and female plants were collected bi-weekly during the growing season and analyzed with a LECO FP-528 nitrogen analyzer after air- and freeze-drying. A conversion factor of kA = 5.7 was applied to obtain the protein content. Total protein content in sea buckthorn leaves showed very small differences between male and female plants and from either freeze-dried or air-dried materials. There were significant fluctuations among harvest periods in both years. Based on the results of this experiment, sea buckthorn leaves should be harvested from late July to early August since leaf protein content peaked around this period of time and started to decline significantly by the middle of August. Key words: Sea buckthorn, Hippophae rhamnoides L., leaf protein


Sign in / Sign up

Export Citation Format

Share Document