scholarly journals Respuestas fisiológicas de Zea mays durante la infección por Ustilago maydis bajo diferentes concentraciones de humus en suelo

Author(s):  
Lucila Méndez-Morán ◽  
Iván David Meza-Canales ◽  
Celia Robles-Murguía ◽  
América Loza-Llamas

The available resources during plant development, sometimes plant can be limited due to energy used during physiological plant defense to pathogens attacks. The main of this work was the physiological analysis of Zea mays plants development under different sustainable fertilization systems, as the earthworm-humus, and their relation with the response to Ustilago maydis infection, a biotrophyc fungus that causes the disease known as common coal or cuitlacoche in corn. Mize seedlings developed with different % of humus/soil under greenhouse conditions were inoculated with U. maydis (T1), and plants not inoculated as control (T0). Physiological and growth measurements in T1 showed a significant effect on the plant, the best was a 25%. After infection, the plants growth was lower as a result in decrease in photosynthesis activity, however, the presence of humus partially counteracts the fungus infection. High concentrations of humus reflected a negative effect on plant growth. In the future, the studies in the field will serve to deduce the importance of these agricultural practices in plant-fungus responses.

2021 ◽  
Author(s):  
ESTHER AURORA RUIZ HUERTA ◽  
Maria Aurora Armienta Hernández ◽  
Joseph G. Dubrovsky ◽  
Juan Miguel Gómez Bernal

Abstract Potentially toxic metals and metalloids present in mining residues can affect ecosystems, particularly plant growth and development. In this study we evaluated As and heavy metal (Fe, Zn, Cu, Cd, Pb) contents in maize (Zea mays L) plants grown in soils collected near (40 m), at intermediate (400 m) and remote (3000 m) distances from mine tailings near Taxco City, Mexico. Soils sampled near and at intermediate sites from the tailings contained high levels of heavy metals which were 3- to 55-fold higher compared to the control samples. The heavy metal and As content in plants reflected the soil contamination being the greatest for most studied elements in root samples followed by stems, leaves, and kernels. Though plants were capable of completing their life cycle and producing the seeds, high bioaccumulation levels had a strong impact on plant development. Abnormalities in the organs like malformations in reproductive structures (tassel and ear), reduction in the phytomer number and the plant height were present. Microscopic studies and morphometric analyses suggest that strongly affected plant growth result from negative and synergistic action of heavy metals and As in soils on cell growth and cell production. This study showed that maize grown near mine tailings accumulates high levels of heavy metals and As which decrease significantly plant yield and could be dangerous if consumed by animals and humans.


2020 ◽  
Vol 53 (2) ◽  
Author(s):  
Muhammad Mubeen ◽  
Asghari Bano ◽  
Barkat Ali ◽  
Zia Ul Islam ◽  
Ashfaq Ahmad ◽  
...  

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 573-576 ◽  
Author(s):  
I.E. Yates ◽  
C.C. Reilly

The influence of stage of fruit development and plant growth regulators on somatic embryogenesis and the relation of cultivar response on somatic embryogenesis and subsequent plant development have been investigated in eight cultivars of pecan [Carya illinoensis (Wangenh.) C. Koch]. Explants from the micropylar region of the ovule were more embryogenic when removed from fruits in the liquid endosperm stage than were intact ovules from less-mature fruits or from cotyledonary segments of more-mature fruits. Explants conditioned on medium containing auxin alone or auxin + cytokinin produced more somatic embryos than medium containing cytokinin alone. Under the conditions of this study, frequency of embryogenesis, as well as the germination of somatic embryos leading to plant development, indicated appreciable variation among cultivars. Plant development was greatest by far from somatic embryos of `Schley' than other cultivars studied.


2021 ◽  
Vol 9 (4) ◽  
pp. 870
Author(s):  
Muhammad Aammar Tufail ◽  
María Touceda-González ◽  
Ilaria Pertot ◽  
Ralf-Udo Ehlers

Plant growth promoting endophytic bacteria, which can fix nitrogen, plays a vital role in plant growth promotion. Previous authors have evaluated the effect of Gluconacetobacter diazotrophicus Pal5 inoculation on plants subjected to different sources of abiotic stress on an individual basis. The present study aimed to appraise the effect of G. diazotrophicus inoculation on the amelioration of the individual and combined effects of drought and nitrogen stress in maize plants (Zea mays L.). A pot experiment was conducted whereby treatments consisted of maize plants cultivated under drought stress, in soil with a low nitrogen concentration and these two stress sources combined, with and without G. diazotrophicus seed inoculation. The inoculated plants showed increased plant biomass, chlorophyll content, plant nitrogen uptake, and water use efficiency. A general increase in copy numbers of G. diazotrophicus, based on 16S rRNA gene quantification, was detected under combined moderate stress, in addition to an increase in the abundance of genes involved in N fixation (nifH). Endophytic colonization of bacteria was negatively affected by severe stress treatments. Overall, G. diazotrophicus Pal5 can be considered as an effective tool to increase maize crop production under drought conditions with low application of nitrogen fertilizer.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sai Guo ◽  
Wu Xiong ◽  
Xinnan Hang ◽  
Zhilei Gao ◽  
Zixuan Jiao ◽  
...  

Abstract Background Microbiomes play vital roles in plant health and performance, and the development of plant beneficial microbiomes can be steered by organic fertilizer inputs. Especially well-studied are fertilizer-induced changes on bacteria and fungi and how changes in these groups alter plant performance. However, impacts on protist communities, including their trophic interactions within the microbiome and consequences on plant performance remain largely unknown. Here, we tracked the entire microbiome, including bacteria, fungi, and protists, over six growing seasons of cucumber under different fertilization regimes (conventional, organic, and Trichoderma bio-organic fertilization) and linked microbial data to plant yield to identify plant growth-promoting microbes. Results Yields were higher in the (bio-)organic fertilization treatments. Soil abiotic conditions were altered by the fertilization regime, with the prominent effects coming from the (bio-)organic fertilization treatments. Those treatments also led to the pronounced shifts in protistan communities, especially microbivorous cercozoan protists. We found positive correlations of these protists with plant yield and the density of potentially plant-beneficial microorganisms. We further explored the mechanistic ramifications of these relationships via greenhouse experiments, showing that cercozoan protists can positively impact plant growth, potentially via interactions with plant-beneficial microorganisms including Trichoderma, the biological agent delivered by the bio-fertilizer. Conclusions We show that protists may play central roles in stimulating plant performance through microbiome interactions. Future agricultural practices might aim to specifically enhance plant beneficial protists or apply those protists as novel, sustainable biofertilizers.


Author(s):  
Mervat H. Hussein ◽  
Eladl Eltanahy ◽  
Alaa Fathy Al Bakry ◽  
Nesrein Elsafty ◽  
Maha M. Elshamy

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 267
Author(s):  
Anderson do Espirito Santo Pereira ◽  
Halley Caixeta Oliveira ◽  
Leonardo Fernandes Fraceto ◽  
Catherine Santaella

Our agriculture is threatened by climate change and the depletion of resources and biodiversity. A new agriculture revolution is needed in order to increase the production of crops and ensure the quality and safety of food, in a sustainable way. Nanotechnology can contribute to the sustainability of agriculture. Seed nano-priming is an efficient process that can change seed metabolism and signaling pathways, affecting not only germination and seedling establishment but also the entire plant lifecycle. Studies have shown various benefits of using seed nano-priming, such as improved plant growth and development, increased productivity, and a better nutritional quality of food. Nano-priming modulates biochemical pathways and the balance between reactive oxygen species and plant growth hormones, resulting in the promotion of stress and diseases resistance outcoming in the reduction of pesticides and fertilizers. The present review provides an overview of advances in the field, showing the challenges and possibilities concerning the use of nanotechnology in seed nano-priming, as a contribution to sustainable agricultural practices.


2018 ◽  
Vol 103 (10) ◽  
pp. 3729-3736 ◽  
Author(s):  
Arash Derakhshan ◽  
Tim I M Korevaar ◽  
Peter N Taylor ◽  
Deborah Levie ◽  
Monica Guxens ◽  
...  

Abstract Context Thyroperoxidase antibody (TPOAb) positivity is a major risk factor for gestational thyroid dysfunction. During the first 18 to 20 weeks of pregnancy, high concentrations of human chorionic gonadotropin (hCG) stimulate the thyroid to ensure adequate thyroid hormone availability for the developing fetus. However, TPOAb-positive women have an impaired thyroidal response to hCG stimulation. Objective To study the association of maternal TPOAb positivity during pregnancy with child IQ. Design, Setting, and Participants This study was embedded in two prospective birth cohorts: Generation R (Rotterdam, the Netherlands) and Avon Longitudinal Study of Parents and Children (ALSPAC; United Kingdom). Mother-child pairs with available data on early pregnancy TPOAb (≤18 weeks of gestation) and offspring IQ were included (n = 3637 for Generation R and n = 2396 for ALSPAC). Main Outcome Measures Child IQ at 5 to 10 years of age. Results In Generation R, TPOAb positivity was associated with a 2.0 ± 0.9-point lower mean child IQ (P = 0.03). Sensitivity analyses showed negative effect estimates already from TPOAb concentrations considerably lower than currently used manufacturer cutoffs. In ALSPAC, neither TPOAb positivity nor TPOAb concentrations below manufacturer cutoffs were associated with child IQ (TPOAb positivity: 0.7 ± 1.0; P = 0.45). Adjustment for maternal TSH or free T4 concentrations or urinary iodine/creatinine ratio did not change the results. Conclusion TPOAb positivity during pregnancy was associated with lower child IQ in Generation R but not in ALSPAC. Further studies are needed to elucidate whether differences between the study populations, such as maternal iodine status, could be the underlying cause for these differences.


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