scholarly journals Long-term mild heat causes post-mitotic pollen abortion through a local effect on flowers

2021 ◽  
Author(s):  
Jiemeng Xu ◽  
Stuart Jansma ◽  
Mieke Wolters-Arts ◽  
Peter de Groot ◽  
Ivo Rieu
Keyword(s):  
Pollen Development ◽  
Pollen Viability ◽  
Systemic Effect ◽  
Local Effect ◽  
Pollen Abortion ◽  
Mild Heat ◽  
Biochemical Analyses ◽  
Microspore Stage ◽  
Whole Plants

Crop reproductive success is significantly challenged by heatwaves, which are increasing in frequency and severity globally. A major reason is reduced male fertility due to deviations in pollen development, but the mechanism behind this is not well understood. Here, long-term mild heat (LTMH) treatment, mimicking a heatwave, was applied locally to flowers or to whole plants and followed up by cytological, transcriptomic and biochemical analyses. LTMH was shown to act directly on the flowers and not via a systemic effect on other plant tissue. The meiosis to early microspore stage was the most sensitive to LTMH and three days of exposure around this period was sufficient to significantly reduce pollen viability. Extensive cytological analysis showed that abnormalities in pollen development could first be observed after pollen mitosis I, while tapetum development appeared unaffected. Transcriptomic and biochemical analyses suggested that pollen development suffered from tapetal ER stress and that there was a limited role for oxidative stress. These characteristics differentiate the response of developing anthers and pollen to LTMH from the response to severe heat stress.

Study of the Changes in Insoluble Polysaccharides during Pollen Development in Rice (Oryza sativa L.) by Microscopic Multispectral Imaging

2010 ◽  
Vol 16 (4) ◽  
pp. 488-501 ◽  
Author(s):  
Shunan Liu ◽  
Lei Pan ◽  
Qiongshui Wu ◽  
Yaojun Hu ◽  
Xiaojun Chen ◽  
...  
Keyword(s):  
Pollen Development ◽  
Multispectral Imaging ◽  
Oryza Sativa L ◽  
Periodic Acid ◽  
Pollen Abortion ◽  
Periodic Acid Schiff ◽  
Steep Decrease ◽  
Multispectral Analysis ◽  
Microspore Stage ◽  
Insoluble Polysaccharides

AbstractMultispectral analysis combined with the Periodic Acid-Schiff method was used to investigate cytological features of insoluble polysaccharides and changes in total insoluble polysaccharide content (TPC) during pollen development in rice, including four cytoplasmic male sterility lines (MSLs) and their corresponding fertility-maintaining lines (FMLs). The multispectral curves of the relative transmittance value (RTV) and the images of developing pollen cells were obtained across a range of successive wavelengths (400–720 nm). A minimum RTV was found near 550 nm indicating an absorption peak of the TPC. Thus, the TPC was measured using the RTV of 550 nm. In the four FMLs, the minimum TPC of developing pollen cells occurred at the late microspore stage, while the maximum TPC occurred at the mature pollen grain stage. The TPC levels of pollen cells were significantly higher in the four FMLs than in their corresponding MSLs during and after pollen abortion. Notably, a steep decrease of multispectral curves at 420 nm appeared before the occurrence of abortion, implying a marker associated with pollen abortion in rice. Our results will be helpful for exploring the changes in TPC during pollen ontogenesis in rice and provide a novel method for the study of bio-macromolecules.

scholarly journals Efficient Protocol for Improving the Development of Cryopreserved Embryonic Axes of Chestnut (Castanea sativa Mill.) by Encapsulation–Vitrification

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 231
Author(s):  
Mariam Gaidamashvili ◽  
Eka Khurtsidze ◽  
Tamari Kutchava ◽  
Maurizio Lambardi ◽  
Carla Benelli
Keyword(s):  
Activated Charcoal ◽  
Castanea Sativa ◽  
Alginate Beads ◽  
Embryonic Axes ◽  
Root Regrowth ◽  
Castanea Sativa Mill ◽  
Whole Plants ◽  
Long Term Preservation ◽  
Direct Immersion

An optimized cryopreservation protocol for embryonic axes (EAs) of chestnut (Castanea sativa Mill.) has been developed based on the encapsulation–vitrification procedure. EAs of mature seeds were aseptically dissected and encapsulated in alginate beads with or without 0.3% (w/v) activated charcoal (AC). Embedded EAs were dehydrated with Plant Vitrification Solution 2 for different treatment times up to 120 min, followed by direct immersion in liquid nitrogen. Cryopreserved embryonic axes encapsulated with AC showed higher survival (70%) compared to those encapsulated without AC (50%). Sixty-four percent of embryonic axes, from synthetic seeds with AC, subsequently developed as whole plants. Plantlet regrowth was faster in AC-encapsulated EAs and showed enhanced postcryopreservation shoot and root regrowth over 2 cm after five weeks from rewarming. Results indicate that encapsulation–vitrification with activated charcoal added to the beads is an effective method for the long-term preservation of Castaneasativa embryonic axes.

High Fat Diet Mediates Amyloid-β Cleaving Enzyme 1 Phosphorylation and SUMOylation, Enhancing Cognitive Impairment in APP/PS1 Mice

2021 ◽  
pp. 1-14
Author(s):  
Jian Bao ◽  
Zheng Liang ◽  
Xiaokang Gong ◽  
Jing Yu ◽  
Yifan Xiao ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
High Fat Diet ◽  
Amyloid Β ◽  
Normal Diet ◽  
Standard Diet ◽  
High Fat ◽  
Augmented Learning ◽  
Biochemical Analyses ◽  
Modifiable Lifestyle Factors

Background: Alzheimer’s disease (AD) is the most common form of dementia in older adults and extracellular accumulation of amyloid-β (Aβ) is one of the two characterized pathologies of AD. Obesity is significantly associated with AD developing factors. Several studies have reported that high fat diet (HFD) influenced Aβ accumulation and cognitive performance during AD pathology. However, the underlying neurobiological mechanisms have not yet been elucidated. Objective: The objective of this study was to explore the underlying neurobiological mechanisms of HFD influenced Aβ accumulation and cognitive performance during AD pathology. Methods: 2.5-month-old male APP/PS1 mice were randomly separated into two groups: 1) the normal diet (ND) group, fed a standard diet (10 kcal%fat); and 2) the HFD group, fed a high fat diet (40 kcal%fat, D12492; Research Diets). After 4 months of HFD or ND feeding, mice in the two groups were subjected for further ethological, morphological, and biochemical analyses. Results: A long-term HFD diet significantly increased perirenal fat and impaired dendritic integrity and aggravated neurodegeneration, and augmented learning and memory deficits in APP/PS1 mice. Furthermore, the HFD increased beta amyloid cleaving enzyme 1 (BACE1) dephosphorylation and SUMOylation, resulting in enhanced enzyme activity and stability, which exacerbated the deposition of amyloid plaques. Conclusion: Our study demonstrates that long-term HFD consumption aggravates amyloid-β accumulation and cognitive impairments, and that modifiable lifestyle factors, such as obesity, can induce BACE1 post-modifications which may contribute to AD pathogenesis.

scholarly journals Identification and Verification of Genes Related to Pollen Development and Male Sterility Induced by High Temperature in Thermo-sensitive Genic Male Sterile Wheat Line YanZhan 4110S

2020 ◽  
Author(s):  
Xuetong Yang ◽  
Jiali Ye ◽  
Fuqiang Niu ◽  
Yi Feng ◽  
Xiyue Song
Keyword(s):  
Gene Silencing ◽  
Male Sterility ◽  
Mosaic Virus ◽  
Pollen Development ◽  
Bioinformatics Analysis ◽  
Virus Induced Gene Silencing ◽  
Wheat Line ◽  
Pollen Abortion ◽  
Hub Genes ◽  
Genic Male Sterility

Abstract Background: Environment-sensitive genic male sterility is of vital importance to hybrid vigor in crop production and breeding, therefore, it is meaningful to identify and study the function of the genes related to pollen development and male sterility, which still not fully understanding currently. In this study, Yanzhan 4110S, a new thermo-sensitive genic male sterility (TGMS) wheat line, and its near isogenic line Yanzhan 4110 were carried out cytological features observation, bioinformatics analysis to investgate the abortion state and identified the genes involved in pollen development which have fertility regulation function. Barely stripe mosaic virus-induced gene silencing was used to verify the genes function.Results: Cytological analysis showed pollen abortion event of Yanzhan 4110S occur at the later uninucleate stage (Lun) under higher temperature induction (day/night temperatures of 22 °C/20 °C), when the anthers were collected and assessed for transcriptomic profiling through high-throughput sequencing. We then in-depth analyzed the differentially expressed genes (DEGs) by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, the results showed that the occurrence of Yanzhan 4110S male-sterility most likely related to metabolic pathway, including phenylpropanoid biosynthesis in the biosynthesis of other secondary metabolites, starch and sucrose metabolism in carbohydrate metabolism, carbon fixation in photosynthetic organisms as well as carbon metabolism in energy metabolism. The weighted gene co-expression network analysis in the transcriptome profiles further identified some hub genes, where the key genes involved in those pathways were intersection between the unique DEGs of Yanzhan 4110S in anther and hub genes, totally 228 genes, which were highly related to pollen development including TaMut11 and TaSF3. Moreover, further verification through barely stripe mosaic virus-induced gene silencing elucidated that the silencing of TaMut11 and TaSF3 caused pollen abortion, finally resulting in the declination of fertility. So, the genes TaMut11 and TaSF3 are related to fertility conversion of Yanzhan 4110S.Conclusion: Through comparative transcriptome bioinformatics analysis, the genes TaMut11 and TaSF3 associated with pollen development and male sterility induced by high temperature were identified in Yanzhan 4110S, and verificated by barely stripe mosaic virus-induced gene silencing. These findings provided researching the abortive mechanism in environment-sensitive genic male sterility wheat.

scholarly journals Overexpression of Two CCCH-type Zinc-Finger Protein Genes Leads to Pollen Abortion in Brassica campestris ssp. chinensis

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1287
Author(s):  
Liai Xu ◽  
Tingting Liu ◽  
Xingpeng Xiong ◽  
Weimiao Liu ◽  
Youjian Yu ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Zinc Finger ◽  
Pollen Development ◽  
Brassica Campestris ◽  
Zinc Finger Protein ◽  
Function Analysis ◽  
Pollen Grains ◽  
Functional Redundancy ◽  
Pollen Abortion ◽  
Finger Protein

The pollen grains produced by flowering plants are vital for sexual reproduction. Previous studies have shown that two CCCH-type zinc-finger protein genes in Brassica campestris, BcMF30a and BcMF30c, are involved in pollen development. Due to their possible functional redundancy, gain-of-function analysis is helpful to reveal their respective biological functions. Here, we found that the phenotypes of BcMF30a and BcMF30c overexpression transgenic plants driven by their native promoters were similar, suggesting their functional redundancy. The results showed that the vegetative growth was not affected in both transgenic plants, but male fertility was reduced. Further analysis found that the abortion of transgenic pollen was caused by the degradation of pollen contents from the late uninucleate microspore stage. Subcellular localization analysis demonstrated that BcMF30a and BcMF30c could localize in cytoplasmic foci. Combined with the studies of other CCCH-type genes, we speculated that the overexpression of these genes can induce the continuous assembly of abnormal cytoplasmic foci, thus resulting in defective plant growth and development, which, in this study, led to pollen abortion. Both the overexpression and knockout of BcMF30a and BcMF30c lead to abnormal pollen development, indicating that the appropriate expression levels of these two genes are critical for the maintenance of normal pollen development.

scholarly journals The Major Factors Causing the Microspore Abortion of Genic Male Sterile Mutant NWMS1 in Wheat (Triticum aestivum L.)

2019 ◽  
Vol 20 (24) ◽  
pp. 6252 ◽  
Author(s):  
Junchang Li ◽  
Jing Zhang ◽  
Huijuan Li ◽  
Hao Niu ◽  
Qiaoqiao Xu ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Male Sterility ◽  
Genetic Research ◽  
Triticum Aestivum L ◽  
Anther Development ◽  
Sucrose Metabolism ◽  
Male Sterile ◽  
Pollen Abortion ◽  
Microspore Stage ◽  
Regulation Model

Male sterility is a valuable trait for genetic research and production application of wheat (Triticum aestivum L.). NWMS1, a novel typical genic male sterility mutant, was obtained from Shengnong 1, mutagenized with ethyl methane sulfonate (EMS). Microstructure and ultrastructure observations of the anthers and microspores indicated that the pollen abortion of NWMS1 started at the early uninucleate microspore stage. Pollen grain collapse, plasmolysis, and absent starch grains were the three typical characteristics of the abnormal microspores. The anther transcriptomes of NWMS1 and its wild type Shengnong 1 were compared at the early anther development stage, pollen mother cell meiotic stage, and binucleate microspore stage. Several biological pathways clearly involved in abnormal anther development were identified, including protein processing in endoplasmic reticulum, starch and sucrose metabolism, lipid metabolism, and plant hormone signal transduction. There were 20 key genes involved in the abnormal anther development, screened out by weighted gene co-expression network analysis (WGCNA), including SKP1B, BIP5, KCS11, ADH3, BGLU6, and TIFY10B. The results indicated that the defect in starch and sucrose metabolism was the most important factor causing male sterility in NWMS1. Based on the experimental data, a primary molecular regulation model of abnormal anther and pollen developments in mutant NWMS1 was established. These results laid a solid foundation for further research on the molecular mechanism of wheat male sterility.

An ultrastructural study of pollen development in tomato (Lycopersicon esculentum). I. Tetrad to early binucleate microspore stage

1993 ◽  
Vol 71 (8) ◽  
pp. 1039-1047 ◽  
Author(s):  
P. L. Polowick ◽  
V. K. Sawhney
Keyword(s):  
Endoplasmic Reticulum ◽  
Lycopersicon Esculentum ◽  
Ultrastructural Study ◽  
Pollen Development ◽  
Pollen Wall ◽  
Ultrastructural Changes ◽  
Dense Matrix ◽  
Tetrad Stage ◽  
Microspore Stage ◽  
Electron Dense Matrix

Microspores undergo considerable ultrastructural changes between the tetrad and early binucleate microspore stages of microsporogenesis in tomato (Lycopersicon esculentum). Pollen wall deposition began late in the tetrad stage, and by the early microspore stage a lamellar foot layer and tectum were deposited. Sculpturing of the tectum was evident by the early binucleate microspore stage. Dictyosomes and vesicles were abundant during the period of pollen wall formation. Plastids were associated with the endoplasmic reticulum (ER) to form plastid–ER complexes, from the late tetrad to the vacuolate microspore stage. At the vacuolate microspore stage, endoplasmic reticulum independent of plastids was also observed, and at the early binucleate microspore stage ER was not associated with plastids. Free ribosomes were evenly distributed throughout the cytoplasm until the vacuolate microspore stage when they were organized into polysomes. Mitochondria were spherical to ellipsoid, with an electron-dense matrix and swollen cristae, until the early binucleate microspore stage when they were highly elongate and became convoluted. Key words: Lycopersicon esculentum, microsporogenesis, pollen development, tetrads, tomato, ultrastructure.

Tapetal development and abiotic stress: a centre of vulnerability

2012 ◽  
Vol 39 (7) ◽  
pp. 553 ◽  
Author(s):  
Roger W. Parish ◽  
Huy A. Phan ◽  
Sylvana Iacuone ◽  
Song F. Li
Keyword(s):  
Cell Wall ◽  
Abiotic Stress ◽  
Oryza Sativa L ◽  
Triticum Aestivum L ◽  
Pollen Abortion ◽  
Cell Wall Invertase ◽  
Developmental Program ◽  
Specific Effects ◽  
Hexose Sugars ◽  
Microspore Stage

Many self-fertilising crops are particularly sensitive to abiotic stress at the reproductive stage. In rice (Oryza sativa L.) and wheat (Triticum aestivum L.), for example, abiotic stress during meiosis and the young microspore stage indicates the tapetum is highly vulnerable and that the developmental program appears to be compromised. Tapetal hypertrophy can occur as a consequence of cold and drought stress, and programmed cell death (PCD) is delayed or inhibited. Since the correct timing of tapetal PCD is essential for pollen reproduction, substantial losses in grain yield occur. In wheat and rice, a decrease in tapetal cell wall invertase levels is correlated with pollen abortion and results in the amount of hexose sugars reaching the tapetum, and subsequently the developing microspores, being severely reduced (‘starvation hypothesis’). ABA and gibberellin levels may be modified by cold and drought, influencing levels of cell wall invertase(s) and the tapetal developmental program, respectively. Many genes regulating tapetal and microspore development have been identified in Arabidopsis thaliana (L.) Heynh. and rice and the specific effects of abiotic stresses on the program and pathways can now begin to be assessed.

Aspterric Acid and 6-Hydroxymellein, Inhibitors of Pollen Development in Arabidopsis thaliana, Produced by Aspergillus terreus

2002 ◽  
Vol 57 (5-6) ◽  
pp. 459-464 ◽  
Author(s):  
Atsumi Shimada ◽  
Miyako Kusano ◽  
Sumiyo Takeuchi ◽  
Shozo Fujioka ◽  
Tomohisa Inokuchi ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Microscopic Examination ◽  
Pollen Development ◽  
Aspergillus Terreus ◽  
Higher Plants ◽  
Molecular Investigation ◽  
Microspore Stage ◽  
Stage 1

Aspterric acid (1) and 6-hydroxymellein (2), inhibitors of pollen development in Arabidopsis thaliana, have been isolated fromthe fungus Aspergillus terreus. 1 and 2 inhibited the pollen development at concentrations of 38 and 52 μᴍ, respectively. The microscopic examination of pollen development suggested that the inhibition by the treatment with 1 caused at meiosis and the inhibition by the treatment with 2 caused at microspore stage. 1 and 2 could be useful agents for the molecular investigation of anther and pollen development in higher plants.

Transgenic MSH overexpression attenuates the metabolic effects of a high-fat diet

2007 ◽  
Vol 293 (1) ◽  
pp. E121-E131 ◽  
Author(s):  
Michelle Lee ◽  
Andrea Kim ◽  
Streamson C. Chua ◽  
Silvana Obici ◽  
Sharon L. Wardlaw
Keyword(s):  
High Fat Diet ◽  
Metabolic Effects ◽  
High Fat ◽  
Fat Percentage ◽  
Male And Female ◽  
Fat Accumulation ◽  
Low Fat Diet ◽  
Hepatic Fat ◽  
Biochemical Analyses

To determine whether long-term melanocortinergic activation can attenuate the metabolic effects of a high fat diet, mice overexpressing an NH2-terminal POMC transgene that includes α- and γ3-MSH were studied on either a 10% low-fat diet (LFD) or 45% high-fat diet (HFD). Weight gain was modestly reduced in transgenic (Tg-MSH) male and female mice vs. wild type (WT) on HFD ( P < 0.05) but not LFD. Substantial reductions in body fat percentage were found in both male and female Tg-MSH mice on LFD ( P < 0.05) and were more pronounced on HFD ( P < 0.001). These changes occurred in the absence of significant feeding differences in most groups, consistent with effects of Tg-MSH on energy expenditure and partitioning. This is supported by indirect calorimetry studies demonstrating higher resting oxygen consumption and lower RQ in Tg-MSH mice on the HFD. Tg-MSH mice had lower fasting insulin levels and improved glucose tolerance on both diets. Histological and biochemical analyses revealed that hepatic fat accumulation was markedly reduced in Tg-MSH mice on the HFD. Tg-MSH also attenuated the increase in corticosterone induced by the HFD. Higher levels of Agrp mRNA, which might counteract effects of the transgene, were measured in Tg-MSH mice on LFD ( P = 0.02) but not HFD. These data show that long-term melanocortin activation reduces body weight, adiposity, and hepatic fat accumulation and improves glucose metabolism, particularly in the setting of diet-induced obesity. Our results suggest that long-term melanocortinergic activation could serve as a potential strategy for the treatment of obesity and its deleterious metabolic consequences.

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