scholarly journals Effects of High Temperature on Embryological Development and Hormone Profile in Flowers and Leaves of Common Buckwheat (Fagopyrum esculentum Moench)

2019 ◽  
Vol 20 (7) ◽  
pp. 1705 ◽  
Author(s):  
Agnieszka Płażek ◽  
Aneta Słomka ◽  
Przemysław Kopeć ◽  
Michał Dziurka ◽  
Marta Hornyák ◽  
...  

Common buckwheat is a valuable crop, mainly due to the beneficial chemical composition of its seeds. However, buckwheat cultivation is limited because of unstable seed yield. The most important reasons for the low yield include embryo and flower abortion. The aim of this work is to verify whether high temperature affects embryological development in this plant species. The experiment was conducted on plants of a Polish cultivar ‘Panda’ and strain PA15, in which the percentage of degenerating embryo sacs was previously determined and amounted to 32% and 10%, respectively. The plants were cultivated in phytotronic conditions at 20 °C (control), and 30 °C (thermal stress). The embryological processes and hormonal profiles in flowers at various developmental stages (buds, open flowers, and wilted flowers) and in donor leaves were analyzed in two-month-old plants. Significant effects of thermal stress on the defective development of female gametophytes and hormone content in flowers and leaves were observed. Ovules were much more sensitive to high temperature than pollen grains in both genotypes. Pollen viability remained unaffected at 30 °C in both genotypes. The effect of temperature on female gametophyte development was visible in cv. Panda but not in PA15 buds. A drastic reduction in the number of properly developed embryo sacs was clear in open flowers at 30 °C in both genotypes. A considerable increase in abscisic acid in open flowers ready for fertilization may serve as a signal inducing flower senescence observed in the next few days. Based on embryological analyses and hormone profiles in flowers, we conclude that cv. ‘Panda’ is more sensitive to thermal stress than strain PA15, mainly due to a much earlier response to thermal stress involving impairment of embryological processes already in the flower buds.

2012 ◽  
Vol 39 (12) ◽  
pp. 1009 ◽  
Author(s):  
Viola Devasirvatham ◽  
Pooran M. Gaur ◽  
Nalini Mallikarjuna ◽  
Raju N. Tokachichu ◽  
Richard M. Trethowan ◽  
...  

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.


2022 ◽  
Vol 28 (1) ◽  
pp. 92-98
Author(s):  
Cristiane Gonçalves Souza ◽  
Sabrina Maihave Barbosa Ramos ◽  
Silvia Nietsche ◽  
Clivia Carolina Fiorilo Possobom ◽  
Elka Fabiana Aparecida Almeida ◽  
...  

Abstract Adenium obesum (Forssk.) Roem. & Schult., popularly known as desert rose, has become a valuable ornamental plant. In floriculture, the production of hybrids is prioritized. Hence, knowledge on floral biology and sexual reproduction of the target species is fundamental. The objectives of this study were: (1) to test sucrose concentrations and temperatures for in vitro germination of A. obesum pollen grains; (2) to identify the effect of temperature on the viability of A. obesum pollen grains; and (3) to evaluate the viability of pollen grains and stigma receptivity in pre-anthesis, at flower opening, and 72 h post-flower opening in three accessions of A. obesum. A significant relationship between temperatures and sucrose concentrations was observed in the in vitro germination test. The highest percentage of in vitro germination of pollen grains, 39.81%, was observed at an estimated temperature of 26.05 °C. Desert rose accessions maintained in biochemical oxygen demand (BOD) chambers at 30 °C during a 16-h light photoperiod showed faster flowering, and temperatures ≥ 25 °C induced pollen grain viability percentages above 69%. Temperature is one of the most important abiotic factors, influencing mainly in pollen germination, pollen tube growing and in efficiency fertilization. The ICA-wd accession stood out and can be considered a pollen donor in artificial pollination. The stigmas of flowers were receptive from a day before flower opening until three days after. The two parameters presented above, stigma receptivity and pollen viability, allow inferences about the appropriate time for successful pollination and subsequent fertilization in desert roses.


2020 ◽  
Vol 58 (1) ◽  
pp. 45-53
Author(s):  
M. HORNYAK ◽  
A. PLAZEK ◽  
P. KOPEC ◽  
M. DZIURKA ◽  
J. PASTUSZAK ◽  
...  

2004 ◽  
Vol 129 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Donna J. Clevenger ◽  
James E. Barrett ◽  
Harry J. Klee ◽  
David G. Clark

Pollen viability, in-vivo pollen tube growth, fruit ripening, seed germination, seed weight, whole plant vigor, and natural flower senescence were investigated in homozygous and heterozygous transgenic ethylene-insensitive CaMV35S::etr1-1 petunias (Petunia ×hybrida `Mitchell Diploid'). Homozygous or heterozygous plants were used to determine any maternal and/or paternal effects of the CaMV35S::etr1-1 transgene. All experiments except for those used to determine natural flower senescence characteristics were conducted in both high and low temperature greenhouses to determine the effect of temperature stress on transgenic plants when compared to wild-type. Results indicated that ethylene-insensitive plants had a decrease in pollen viability, root dry mass, seed weight, and seed germination. Fruit ripening, seed germination, and seed weight were maternally regulated. In contrast, the CaMV35S::etr1-1 transgene is completely dominant in its effect on natural flower senescence.


Fagopyrum ◽  
1970 ◽  
Vol 36 (2) ◽  
pp. 37-41
Author(s):  
Shinya Kasajima ◽  
Ikumi Yoshimaru ◽  
Hirotake Itoh

Studies regarding the developmental stage of common buckwheat (Fagopyrum esculentum Moench) have not been adequately performed despite its importance in studying the yield-determining process. In addition, the difference between common buckwheat and Tartary buckwheat (F. tataricum (L.) Gaertn.) is still unclear. In the present study, the differentiation and growth of the growing point until the stage of flower bud appearance were evaluated in the common buckwheat variety ‘Kitawasesoba’ and the Tartary buckwheat variety ‘Manten-Kirari’, which are the leading buckwheat varieties in Hokkaido, Japan. With some exceptions, the developmental stages of ‘Kitawasesoba’ and ‘Manten-Kirari’ can be distinguished. Thus, leaf primordia, axillary flower bud, and terminal flower bud differentiations and growths were observed. Both the common and Tartary buckwheat varieties did not exhibit large differences in the morphology of the growing point. However, the two varieties showed differences in the rates of differentiation and growth.Received: April 11, 2019; accepted: June 8, 2019Keywords: common buckwheat, developmental stage, growing point, Hokkaido, Tartary buckwheat


2018 ◽  
Vol 115 (47) ◽  
pp. E11188-E11197 ◽  
Author(s):  
Joëlle K. Muhlemann ◽  
Trenton L. B. Younts ◽  
Gloria K. Muday

Plant reproduction requires long-distance growth of a pollen tube to fertilize the female gametophyte. Prior reports suggested that mutations altering synthesis of flavonoids, plant specialized metabolites that include flavonols and anthocyanins, impair pollen development in several species, but the mechanism by which flavonols enhanced fertility was not defined. Here, we used genetic approaches to demonstrate that flavonols enhanced pollen development by reducing the abundance of reactive oxygen species (ROS). We further showed that flavonols reduced high-temperature stress-induced ROS accumulation and inhibition of pollen tube growth. The anthocyanin reduced (are) tomato mutant had reduced flavonol accumulation in pollen grains and tubes. This mutant produced fewer pollen grains and had impaired pollen viability, germination, tube growth, and tube integrity, resulting in reduced seed set. Consistent with flavonols acting as ROS scavengers, are had elevated levels of ROS. The pollen viability, tube growth and integrity defects, and ROS accumulation in are were reversed by genetic complementation. Inhibition of ROS synthesis or scavenging of excess ROS with an exogenous antioxidant treatment also reversed the are phenotypes, indicating that flavonols function by reducing ROS levels. Heat stress resulted in increased ROS in pollen tubes and inhibited tube growth, with more pronounced effects in the are mutant that could be rescued by antioxidant treatment. These results are consistent with increased ROS inhibiting pollen tube growth and with flavonols preventing ROS from reaching damaging levels. These results reveal that flavonol metabolites regulate plant sexual reproduction at both normal and elevated temperatures by maintaining ROS homeostasis.


2021 ◽  
Vol 22 (5) ◽  
pp. 2678
Author(s):  
Przemysław Kopeć ◽  
Marta Hornyák ◽  
Jakub Pastuszak ◽  
Anna Szczerba ◽  
Marcin Rapacz ◽  
...  

Common buckwheat (Fagopyrum esculentum Moench), a pseudocereal crop, produces a large number of flowers, but this does not guarantee high seed yields. This species demonstrates strong abortion of flowers and embryos. High temperatures during the generative growth phase result in an increase in the degeneration of embryo sacs. The aim of this study was to investigate proteomic changes in flowers and leaves of two common buckwheat accessions with different degrees of heat tolerance, Panda and PA15. Two-dimensional gel electrophoresis and mass spectrometry techniques were used to analyze the proteome profiles. Analyses were conducted for flower buds, open flowers capable of fertilization, and wilted flowers, as well as donor leaves, i.e., those growing closest to the inflorescences. High temperature up-regulated the expression of 182 proteins. The proteomic response to heat stress differed between the accessions and among their organs. In the Panda accession, we observed a change in abundance of 17, 13, 28, and 11 proteins, in buds, open and wilted flowers, and leaves, respectively. However, in the PA15 accession there were 34, 21, 63, and 21 such proteins, respectively. Fifteen heat-affected proteins were common to both accessions. The indole-3-glycerol phosphate synthase chloroplastic-like isoform X2 accumulated in the open flowers of the heat-sensitive cultivar Panda in response to high temperature, and may be a candidate protein as a marker of heat sensitivity in buckwheat plants.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rui Zhang ◽  
Yujie Meng ◽  
Hejia Song ◽  
Ran Niu ◽  
Yu Wang ◽  
...  

Abstract Background Although exposure to air pollution has been linked to many health issues, few studies have quantified the modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China. Methods The data of daily incidence of influenza and the relevant meteorological data and air pollution data in Ningbo from 2014 to 2017 were retrieved. Low, medium and high temperature layers were stratified by the daily mean temperature with 25th and 75th percentiles. The potential modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo was investigated through analyzing the effects of air pollutants stratified by temperature stratum using distributed lag non-linear model (DLNM). Stratified analysis by sex and age were also conducted. Results Overall, a 10 μg/m3 increment of O3, PM2.5, PM10 and NO2 could increase the incidence risk of influenza with the cumulative relative risk of 1.028 (95% CI 1.007, 1.050), 1.061 (95% CI 1.004, 1.122), 1.043 (95% CI 1.003, 1.085), and 1.118 (95% CI 1.028, 1.216), respectively. Male and aged 7–17 years were more sensitive to air pollutants. Through the temperature stratification analysis, we found that temperature could modify the impacts of air pollution on daily incidence of influenza with high temperature exacerbating the impact of air pollutants. At high temperature layer, male and the groups aged 0–6 years and 18–64 years were more sensitive to air pollution. Conclusion Temperature modified the relationship between air pollution and daily incidence of influenza and high temperature would exacerbate the effects of air pollutants in Ningbo.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 290
Author(s):  
Abdul Kader Alabdullah ◽  
Graham Moore ◽  
Azahara C. Martín

Although most flowering plants are polyploid, little is known of how the meiotic process evolves after polyploidisation to stabilise and preserve fertility. On wheat polyploidisation, the major meiotic gene ZIP4 on chromosome 3B duplicated onto 5B and diverged (TaZIP4-B2). TaZIP4-B2 was recently shown to promote homologous pairing, synapsis and crossover, and suppress homoeologous crossover. We therefore suspected that these meiotic stabilising effects could be important for preserving wheat fertility. A CRISPR Tazip4-B2 mutant was exploited to assess the contribution of the 5B duplicated ZIP4 copy in maintaining pollen viability and grain setting. Analysis demonstrated abnormalities in 56% of meiocytes in the Tazip4-B2 mutant, with micronuclei in 50% of tetrads, reduced size in 48% of pollen grains and a near 50% reduction in grain number. Further studies showed that most of the reduced grain number occurred when Tazip4-B2 mutant plants were pollinated with the less viable Tazip4-B2 mutant pollen rather than with wild type pollen, suggesting that the stabilising effect of TaZIP4-B2 on meiosis has a greater consequence in subsequent male, rather than female gametogenesis. These studies reveal the extraordinary value of the wheat chromosome 5B TaZIP4-B2 duplication to agriculture and human nutrition. Future studies should further investigate the role of TaZIP4-B2 on female fertility and assess whether different TaZIP4-B2 alleles exhibit variable effects on meiotic stabilisation and/or resistance to temperature change.


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