- Theory of coevolution of cytoplasmic male-sterility, nuclear restorer and selfing. [Journal Article]
- JTJ Theor Biol 2019 Jun 13
- Gynodioecy is a sexual polymorphism in angiosperms, where hermaphroditic and female individuals coexist. This is sometimes caused by a cytoplasmic genetic element (CGE) that destroys male functions, …
Gynodioecy is a sexual polymorphism in angiosperms, where hermaphroditic and female individuals coexist. This is sometimes caused by a cytoplasmic genetic element (CGE) that destroys male functions, which is called cytoplasmic male-sterility (CMS). On the other hand, nuclear genes tend to evolve the ability to restore male function. The coevolutionary process of CMS and the restoration has been studied theoretically. Recently, a theoretical study suggested that these coevolutionary dynamics could be influenced by the rate of selfing within populations, although it assumed that the selfing rate of a population was a fixed parameter. Accordingly, we theoretically study the coevolution of three traits in this paper: CMS, nuclear restorer and selfing rate, in which we hypothesize that selfing evolution can suppress CMS evolution under some conditions. The analysis indicates three significant properties of the system; (1) CMS-restorer evolution can result in bistability under a given selfing rate, (2) the coevolution of three traits can realize intermediate levels of selfing, and (3) the evolution of high levels of selfing is conditionally associated with no CMS and/or no restoration, which may support our hypothesis.
- Parietaria major allergens vs pollen in the air we breathe. [Journal Article]
- EREnviron Res 2019 May 30; 176:108514
- CONCLUSIONS: Parietaria aeroallergens show similar pattern of Urticaceae airborne pollen. Urticaceae pollen calendar is as a good tool for allergy prevention. On the other hand, important concentrations of Par j 1 and Par j 2 were located in the breathable fraction (PM2.5), which could explain the asthmatic symptoms in the allergic population to Parietaria.
- Pollen development in male sterile mangosteen (Garcinia mangostana L.) and male fertile seashore mangosteen (Garcinia celebica L.). [Journal Article]
- PProtoplasma 2019 Jun 14
- Mangosteen (Garcinia mangostana L.) is an economically important tropical fruit, yet the reproductive biology of this dioecious plant is complex. Male trees are not known, and female trees have steri…
Mangosteen (Garcinia mangostana L.) is an economically important tropical fruit, yet the reproductive biology of this dioecious plant is complex. Male trees are not known, and female trees have sterile anthers leading to apomixis. We hypothesized that pollen abortion in mangosteen is due to altered tapetum activity during microgametogenesis. Developmental events at the cellular and sub-cellular levels during pollen development in G. mangostana were therefore examined and compared with seashore mangosteen (G. celebica L.), a closely related species with fertile anthers. In G. mangostana, the microspore mother cell had disorganized cytoplasm, including lack of Golgi apparatus and its vesicles, as well as abnormal callose wall accumulation. Globular droplets, which resembled orbicules or Ubisch bodies, were abundant in the locule, including pre-Ubisch bodies found along the tapetal plasma membrane. The tapetum of G. mangostana underwent cell death earlier than the fertile G. celebica, and during the premature death, the mitochondria had dramatically altered shapes. Low accumulation of starch in collapsed microspore mother cells and tetrad cell remnants also suggested that altered cell metabolism is related to pollen abortion in mangosteen. The present results demonstrate the importance of coordinated development between the tapetum and microspores in pollen development and provide new insights into male sterility in mangosteen (G. mangostana).
- Pyrrolizidine Alkaloids: The Botanical Origin of Pollen Collected during the Flowering Period of Echium vulgare and the Stability of Pyrrolizidine Alkaloids in Bee Bread. [Journal Article]
- MMolecules 2019 Jun 13; 24(12)
- Previous studies have shown that pollen products sold as nutritional supplements and used in apitherapy may contain toxic pyrrolizidine alkaloids (PAs) if bees collect pollen from PA-containing plant…
Previous studies have shown that pollen products sold as nutritional supplements and used in apitherapy may contain toxic pyrrolizidine alkaloids (PAs) if bees collect pollen from PA-containing plants, such as Echium vulgare. In this study, the botanical origin of pollen from two observation sites was studied. Despite a high PA content in pollen samples that bees collected during E. vulgare's flowering period, bees were found to collect relatively few Echium pollen loads. Thus, the monitoring of pollen loads collected at the apiaries is unviable to estimate the risk of PA contamination in pollen or bee bread. In a second step, the stability of PAs in bee bread samples containing PAs at concentrations of 2538 ng/g and 98 ng/g was assessed over a period of five or six months, respectively. No significant PA reduction was observed in bee bread stored at 15 °C, but there were overall PA reductions of 39% and 33% in bee bread stored at 30 °C, reflecting hive conditions. While PA N-oxides decreased over time, other types of PAs remained relatively stable. Monitoring PAs in pollen products remains important to ensure consumer safety and should include echivulgarine (and its N-oxide), the major PA type found in pollen from E. vulgare.
- Comprehensive analysis of Ogura cytoplasmic male sterility-related genes in turnip (Brassica rapa ssp. rapifera) using RNA sequencing analysis and bioinformatics. [Journal Article]
- PlosPLoS One 2019; 14(6):e0218029
- 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 lo…
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.
- Mechanics of a Plant in Fluid Flow. [Journal Article]
- JEJ Exp Bot 2019 Jun 13
- Plants live in constantly moving fluid, whether air or water. In response to the loads associated with fluid motion, plants bend and twist, often with great amplitude. These large deformations are no…
Plants live in constantly moving fluid, whether air or water. In response to the loads associated with fluid motion, plants bend and twist, often with great amplitude. These large deformations are not found in traditional engineering application and thus necessitate new specialised scientific developments. Studying Fluid-Structure Interactions (FSI) in botany, forestry and agricultural science is crucial to the optimisation of biomass production for food, energy, and construction materials. FSI are also central in the study of the ecological adaptation of plants to their environment. This review paper surveys the mechanics of FSI on individual plants. We present a short refresher on fluid mechanics then dive in the statics and dynamics of plant-fluid interactions. For every phenomenon considered, we present the appropriate dimensionless numbers to characterise the problem, discuss the implications of these phenomena on biological processes, and propose future research avenues. We cover the concept of reconfiguration while considering poroelasticity, torsion, chirality, buoyancy, and skin friction. We also cover the dynamical phenomena of wave action, flutter, and vortex-induced vibrations.
- A cotton (Gossypium hirsutum) WRKY transcription factor (GhWRKY22) participates in regulating anther/pollen development. [Journal Article]
- PPPlant Physiol Biochem 2019 Jun 06; 141:231-239
- Anther/pollen development is a highly programmed process in flowering plants. However, the molecular mechanism of regulating anther/pollen development is still largely unclear so far. Here, we report…
Anther/pollen development is a highly programmed process in flowering plants. However, the molecular mechanism of regulating anther/pollen development is still largely unclear so far. Here, we report a cotton WRKY transcription factor (GhWRKY22) that functions in anther/pollen development. Quantitative RT-PCR and GUS activity analyses revealed that GhWRKY22 is predominantly expressed in the late developing anther/pollen of cotton. The transgenic Arabidopsis plants expressing GhWRKY22 displayed the male fertility defect with the fewer viable pollen grains. Expression of the genes involved in jasmonate (JA) biosynthesis was up-regulated, whereas expression of the JA-repressors (JAZ1 and JAZ8) was down-regulated in the transgenic Arabidopsis plants expressing GhWRKY22, compared with those in wild type. Yeast one-hybrid and ChIP-qPCR assays demonstrated that GhWRKY22 modulated the expression of JAZ genes by directly binding to their promoters for regulating anther/pollen development. Yeast two-hybrid assay indicated that GhMYB24 could interact with GhJAZ8-A and GhJAZ13-A. Furthermore, expression of AtMYB24, AtPAL2 and AtANS2 was enhanced in the transgenic Arabidopsis plants, owing to GhWRKY22 overexpression. Taking the data together, our results suggest that GhWRKY22 acts as a transcriptional repressor to regulate anther/pollen development possibly by modulating the expression of the JAZ genes.
- Annual growth cycle observation, hybridization and forcing culture for improving the ornamental application of Paeonia lactiflora Pall. in the low-latitude regions. [Journal Article]
- PlosPLoS One 2019; 14(6):e0218164
- Expanding the southern range of herbaceous peony (Paeonia lactiflora Pall.) is a meaningful and worthwhile horticultural endeavor in the Northern Hemisphere. However, high temperatures in winter seri…
Expanding the southern range of herbaceous peony (Paeonia lactiflora Pall.) is a meaningful and worthwhile horticultural endeavor in the Northern Hemisphere. However, high temperatures in winter seriously hinder the bud dormancy release and flowering of peony in the more southern areas of subtropical and tropical regions. Resource introduction and hybridization can contribute to creating new cultivars with high adaptability in a warmer winter climate. In this study, three representative cultivars of P. lactiflora were screened for flowering capabilities and their annual growth cycles were observed to provide information needed for hybridization. Among these three cultivars, 'Hang Baishao' is the best adapted cultivar for southern growing regions and is unique in its ability to thrive in southern areas of N 30°00'. Pollen viability of 'Hang Baishao' was 55.60% based on five measuring methods, which makes it an excellent male parent in hybridization. Hybrid plants among these three cultivars grew well, but all of their flower buds aborted. Additionally, the ability of three growth regulators that advance the flowering of 'Hang Baishao' to promote an indoor cultivation strategy for improving peony application as a potted or cut-flower plant was tested. 5-azacytidine could impact the growth of 'Hang Baishao' and induce dwarfism and small flowers but not advance the flowering time. Gibberellin A3 promoted the sprouting and growth significantly, but all plants eventually withered. Chilling at 0-4°C for four weeks and irrigation with 300 mg/L humic acid was the optimal combination used to hasten flowering and ensure flowering quality simultaneously. These results can lay the foundation for future studies on the chilling requirement trait, bud dormancy release and key functional gene exploration of herbaceous peony. Additionally, this study can also provide guidance for expanding the range of economically important plants with the winter dormancy trait to the low-latitude regions.
- Palynological data of cores MSM5/5-712-2 and PS2863/1-2 from northeastern Fram Strait spanning the last glacial maximum to present. [Journal Article]
- DBData Brief 2019; 24:103899
- The palynogical data of two sites from northeastern Fram Strait (MSM5/5-712 and PS2863) encompassing the last 23,000 years are presented here. The data set first includes the palynomorph concentratio…
The palynogical data of two sites from northeastern Fram Strait (MSM5/5-712 and PS2863) encompassing the last 23,000 years are presented here. The data set first includes the palynomorph concentrations: dinocysts (cysts/g) and their fluxes (cysts/cm2/yr) as well as pollen grains, spores, organic linings, Halodinium, reworked palynomorphs and Pediastrum represented in #/g. It also includes the relative abundance (%) of dinocyst taxa at sites MSM5/5-712 and PS2863. Finally, this Data in Brief comprises reconstructions of sea-surface conditions at the two sites, which include sea-surface temperature (°C) in summer and winter, sea-surface salinity (psu) in summer and winter, sea-ice cover (month/yr) and productivity (gC/m2yr). The most probable values in addition to minimum and maximum possible are reported. The data is presented in function of the cores depth and age. For more details on this data and the chronology of the cores, see .
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- ICTV Virus Taxonomy Profile: Bromoviridae. [Journal Article]
- JGJ Gen Virol 2019 Jun 13
- Bromoviridae is a family of plant viruses with tri-segmented, positive-sense, single-stranded RNA genomes of about 8 kb in total. Genomic RNAs are packaged in separate virions that may also contain s…
Bromoviridae is a family of plant viruses with tri-segmented, positive-sense, single-stranded RNA genomes of about 8 kb in total. Genomic RNAs are packaged in separate virions that may also contain subgenomic, defective or satellite RNAs. Virions are variable in morphology (spherical or bacilliform) and are transmitted between hosts mechanically, in/on the pollen and non-persistently by insect vectors. Members of the family are responsible for major disease epidemics in fruit, vegetable and fodder crops such as tomato, cucurbits, bananas, fruit trees and alfalfa. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Bromoviridae, which is available at www.ictv.global/report/bromoviridae.