Absolute and relative content of carbon and nitrogen differ by sex in Ceratopteris richardii gametophytes

Botany ◽  
2016 ◽  
Vol 94 (5) ◽  
pp. 405-410 ◽  
Author(s):  
Taylor T. Goodnoe ◽  
Jeffrey P. Hill
Keyword(s):  
Sex Determination ◽  
Nutrient Availability ◽  
Abiotic Factors ◽  
Sex Expression ◽  
Dry Mass ◽  
Ceratopteris Richardii ◽  
Carbon And Nitrogen ◽  
Individual Fitness ◽  
Nutrient Effects ◽  
Short Time

When habitats are heterogeneous regarding key abiotic factors, and individual organisms have no control over the environment in which they develop, labile sex expression can allow individuals to adjust their sex based on local environmental conditions, resulting in increased individual fitness. Sexual lability is found extensively in homosporous ferns, where sex expression is often regulated via the pheromone antheridiogen. Nutrient availability may provide additional signals for sex determination in fern gametophytes, particularly if nutrient demands required for sexual development differ by sex. The model fern Ceratopteris richardii Brongn. has a well-characterized antheridiogen response and short time to sexual maturity. Although tests for nutrient effects on sex determination have been conducted in this fern, tests for differences in nutrient demands by sex have not. Elemental analysis demonstrated that 14-day-old ameristic male and meristic female or hermaphrodite gametophytes of C. richardii differ significantly in their relative carbon and nitrogen masses, resulting in significantly dissimilar C:N ratios between the sexes. Average gametophyte dry mass in ameristic males was approximately half that of meristic plants of the same age, and contained less N than meristic gametophytes in both relative and absolute terms. Those characteristic differences in elemental composition imply that variation in nutrient availability could potentially influence sex expression in C. richardii gametophyte populations, rather than regulation of sex determination by the antheridiogen system alone.

Effects of variation in carbon, nitrogen, and phosphorus molarity and stoichiometry on sex determination in the fern Ceratopteris richardii

Botany ◽  
2016 ◽  
Vol 94 (4) ◽  
pp. 249-259 ◽  
Author(s):  
Taylor T. Goodnoe ◽  
Jeffrey P. Hill ◽  
Ken Aho
Keyword(s):  
Sex Determination ◽  
Normal Growth ◽  
Early Response ◽  
Sex Expression ◽  
Dry Mass ◽  
Phenotypic Trait ◽  
Ceratopteris Richardii ◽  
Nitrogen And Phosphorus ◽  
Exogenous Glucose ◽  
Nutrient Effects

Carbon (C), nitrogen (N), and phosphorous (P) are needed by all organisms for basic biological processes. When an individual macronutrient is not accessible, nutrient limitation occurs. The stochiometric balance between multiple nutrients and individual concentrations are both vital for normal growth and development. Labile sex expression in plants is a phenotypic trait predicted to be sensitive to local nutrient conditions because males and females differ in their nutritional demands. We applied concepts from ecological stoichiometry to assess the effects of variation in individual nutrient concentration and multiple macronutrient stoichiometry on sexual development in the fern Ceratopteris richardii Brongn. Manipulation of N, P, and organic and inorganic C was expected to yield variation in the ratio of males to females, consistent with environmental sex-determination theory. Our results suggest nutrient stoichiometry, not strictly concentration, influences sex determination at ambient CO2. However, an early response to population density preempted nutrient effects in elevated CO2 environments with exogenous glucose, in which C. richardii gametophytes presumably grow naturally. Although sex determination is not nutrient-dependent in the latter environment, C:N in the dry mass of meristic gametophytes is influenced by the external nutrient context, suggesting sex determination takes place before abiotic environmental factors subsequently influence plant nutrient uptake.

scholarly journals A Review of Indicators of Healthy Agricultural Soils with Pea Footrot Disease Suppression Potentials

2012 ◽  
Vol 1 (2) ◽  
pp. 235 ◽  
Author(s):  
Ebimieowei Etebu ◽  
A. Mark Osborn
Keyword(s):  
Field Experiments ◽  
Agricultural Soils ◽  
Abiotic Factors ◽  
Disease Incidence ◽  
Soil Health ◽  
Disease Suppression ◽  
Initial Inoculum ◽  
Carbon And Nitrogen ◽  
Short Time

<p>The quality of a soil is often viewed in relation to its ability to suppress plant disease and enhance agricultural productivity. A soil is considered suppressive when, in spite of favourable conditions for disease incidence and development, a pathogen cannot become established, or establishes but produces no disease, or establishes and produces disease for a short time and then declines. The interplay of biotic and abiotic factors has long been known to assert disease suppressive capabilities or otherwise. However, the multi-functionality of soil makes the identification of a single property as a general indicator of soil health an uphill task. In this paper, therefore, some indicators of soil health important to agriculture are reviewed with emphasis on pea footrot disease suppression potentials. Findings show that footrot disease due to <em>Nectria haematococca </em>(anamorph <em>Fusarium solani </em>f.sp <em>pisi</em>) is a globally, economically important disease of peas, and an initial inoculum density of ? 100 pathogenic forms of <em>N. haematococca </em>cells would produce an appreciable level of pea footrot disease depending on the relative amount of phosphorus, carbon and nitrogen present in soil. It would be desirable to confirm pea footrot disease models obtained from pot experiments with results from field experiments.</p>

scholarly journals Nutrient supply controls the linkage between species abundance and ecological interactions in marine bacterial communities

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Tianjiao Dai ◽  
Donghui Wen ◽  
Colin T. Bates ◽  
Linwei Wu ◽  
Xue Guo ◽  
...  
Keyword(s):  
Nutrient Availability ◽  
Copy Number ◽  
Abiotic Factors ◽  
Species Abundance ◽  
Coastal Sediment ◽  
Global Ocean ◽  
Bacterial Growth Rate ◽  
Opposite Pattern ◽  
Microbial Species ◽  
Rare Biosphere

AbstractNutrient scarcity is pervasive for natural microbial communities, affecting species reproduction and co-existence. However, it remains unclear whether there are general rules of how microbial species abundances are shaped by biotic and abiotic factors. Here we show that the ribosomal RNA gene operon (rrn) copy number, a genomic trait related to bacterial growth rate and nutrient demand, decreases from the abundant to the rare biosphere in the nutrient-rich coastal sediment but exhibits the opposite pattern in the nutrient-scarce pelagic zone of the global ocean. Both patterns are underlain by positive correlations between community-level rrn copy number and nutrients. Furthermore, inter-species co-exclusion inferred by negative network associations is observed more in coastal sediment than in ocean water samples. Nutrient manipulation experiments yield effects of nutrient availability on rrn copy numbers and network associations that are consistent with our field observations. Based on these results, we propose a “hunger games” hypothesis to define microbial species abundance rules using the rrn copy number, ecological interaction, and nutrient availability.

scholarly journals Determinants of life-history traits in a fish ectoparasite: a hierarchical analysis

Parasitology ◽  
2011 ◽  
Vol 138 (7) ◽  
pp. 848-857 ◽  
Author(s):  
G. LOOT ◽  
N. POULET ◽  
S. BROSSE ◽  
L. TUDESQUE ◽  
F. THOMAS ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Egg Size ◽  
Life History Traits ◽  
Abiotic Factors ◽  
Individual Characteristics ◽  
Trade Off ◽  
Individual Fitness ◽  
Parasite Number ◽  
Egg Number

SUMMARYObjective. Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We then determined the factors affecting the strength of the trade-off between egg number and egg size. Methods. To do so, we used 4-level (parasite, microhabitat, host and environment) hierarchical models coupled to a field database. Results. Variation in life-history traits was mostly due to individual characteristics measured at the parasite level. At the microhabitat level (fins of fish hosts), parasite number was positively related to body size, egg presence and egg number. Higher parasite number on fins was positively associated with individual parasite fitness. At the host level, host body size was positively related to the individual fitness of the parasite; parasites were bigger and more fecund on bigger hosts. In contrast, factors measured at the environmental level had a weak influence on life-history traits. Finally, a site-dependent trade-off between egg number and egg size existed in this population. Conclusion. Our study illustrates the importance of considering parasite life-history traits in a hierarchical framework to decipher complex links between biotic, abiotic factors and parasite life-history traits.

The effects of light on sex determination in gametophytes of the fern Ceratopteris richardii

2007 ◽  
Vol 120 (5) ◽  
pp. 629-634 ◽  
Author(s):  
Hiroyuki Kamachi ◽  
Orie Iwasawa ◽  
Leslie G. Hickok ◽  
Masaaki Nakayama ◽  
Munenori Noguchi ◽  
...  
Keyword(s):  
Sex Determination ◽  
Ceratopteris Richardii

Antheridiogen concentration and spore size predict gametophyte size in Ceratopteris richardii

Botany ◽  
2012 ◽  
Vol 90 (3) ◽  
pp. 175-179 ◽  
Author(s):  
Mike Ganger ◽  
Tiffany Sturey
Keyword(s):  
Sex Determination ◽  
Environmental Sex Determination ◽  
Wild Type ◽  
Ceratopteris Richardii ◽  
Spore Size ◽  
Male Development ◽  
Homosporous Fern ◽  
Type C ◽  
Slow Growing ◽  
Genetic Mutants

In many plants females invest more in reproduction than males. In organisms that exhibit environmental sex determination, individuals in low-quality environments or who are slow growing are expected to develop into males. The gametophytes of Ceratopteris richardii Brongn., a homosporous fern, may develop as males or hermaphrodites. Hermaphrodites secrete a pheromone called antheridiogen that induces undifferentiated spores to develop as males. Given that induction is not 100% in the presence of antheridiogen, it is hypothesized that resources may alter C. richardii gender decisions. An experiment was undertaken to determine (i) whether spore size predicts gender, (ii) whether spore size predicts gametophyte size, (iii) whether antheridiogen negatively affects the growth of C. richardii, and (iv) whether wild-type C. richardii and him1 mutants (genetic mutants disposed to male development regardless of antheridiogen presence) behave similarly in their response to antheridiogen. Spore size was not predictive of gender but was positively related to both male and hermaphrodite gametophyte size. Antheridiogen was found to slow the growth of male and hermaphrodite gametophytes of the wild type and male gametophytes of the him1 mutant. These results are supportive of the idea that gender may be determined indirectly through antheridiogen’s effect on gametophyte growth.

Factors influencing temporal variation of a Sargassum filipendula (Phaeophyta: Fucales) bed in a subtropical shore

2009 ◽  
Vol 89 (2) ◽  
pp. 315-321 ◽  
Author(s):  
G.B. Jacobucci ◽  
M.O. Tanaka ◽  
F.P.P. Leite
Keyword(s):  
Temporal Variation ◽  
Abiotic Factors ◽  
Sampling Period ◽  
Dry Mass ◽  
Hypnea Musciformis ◽  
Temporal Fluctuations ◽  
Eastern Brazil ◽  
Sargassum Filipendula ◽  
Noticeable Reduction ◽  
Abiotic And Biotic Factors

In the present study, we evaluate the influence of biotic and abiotic factors on temporal fluctuations of Sargassum filipendula in a subtropical shore. Monthly algal samples, abiotic components, amphipod grazer density, and epiphyte biomass were obtained from a Sargassum bed in south-eastern Brazil. Density of S. filipendula fronds decreased during the sampling period, whereas dry mass was more constant, although with a noticeable reduction in the warmer months. Hypnea musciformis was the most frequent epiphyte on S. filipendula, occurring in all sampling periods, although with significant temporal variation. Sargassum filipendula density and dry mass were both influenced by epiphyte dry mass, temperature, and amphipod grazers. Sargassum filipendula biomass negatively influenced total epiphyte biomass, whereas H. musciformis biomass was positively influenced by phosphate, nitrite, and S. filipendula density and negatively influenced by S. filipendula dry mass and amphipod grazer abundance. Algal temporal fluctuations can be related to local abiotic and biotic factors, but the variation observed for S. filipendula and its epiphytes suggest that these factors have quite distinct effects for these algae.

scholarly journals Water restriction in different phenological stages and increased temperature affect cowpea production

2021 ◽  
Vol 45 ◽  
Author(s):  
Juliane Rafaele Alves Barros ◽  
Miguel Julio Machado Guimarães ◽  
Welson Lima Simões ◽  
Natoniel Franklin de Melo ◽  
Francislene Angelotti
Keyword(s):  
Air Temperature ◽  
Water Availability ◽  
Abiotic Factors ◽  
Dry Mass ◽  
Development Stage ◽  
Grain Production ◽  
Water Restriction ◽  
Phenological Stages ◽  
Increased Temperature ◽  
Temperature Regimes

ABSTRACT Water deficit and high temperatures are abiotic factors that most limit plant growth and development. However, its effects depend on crop development stage and on stress duration and intensity. Thus, the objective of was to evaluate the development of cowpea subjected to water restriction in different phenological stages and to increase in air temperature. The experiment was conducted with the cultivar ‘Carijó’, in growth chambers, in a 4 x 3 x 2 factorial arrangement, corresponding to levels of water availability (25, 50, 75, and 100%,), phenological stages (vegetative, flowering and pod filling) and temperature regimes (T°1: 20-26-33 °C e T°2: 24.8-30.8-37.8 °C), respectively. Reduction of water availability in the vegetative and flowering stages caused decrease in grain production. The percentage of aborted flowers was higher in plants maintained under an increased temperature of +4.8 °C, with consequent reduction in grain production. Higher water availability values favored shoot and root dry mass production. Increase of 4.8 °C did not affect shoot and root dry mass but reduced water use efficiency by about 83%. The highest enzymatic activities of CAT, GPX and SOD were found in plants subjected to the temperature of +4.8 °C. Only APX showed lower enzymatic activity with increasing temperature. The cv. ‘Carijó’ is more sensitive to the 4.8 °C increase in air temperature than to water deficits.

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