Fig 3 - uploaded by José-Antonio Munive
Content may be subject to copyright.
Main structures of a three-week old nodule formed on common bean (Phaseolus vulgaris L., cultivar Bayomex) root, inoculated with Rhizobium etli CE-3. Peridermis (a), parenchyma (b), vascular bundle (c), developing zone (d), endodermis (e), and inner cortex formed by infected (f) and non-infected (g) cells
Source publication
We studied morphological changes over time by nodules formed on the root system of the common bean (Phaseolus vulgaris L.). Two cultivars, Bayomex and Cacahuate 72 with growth habit Type I and the Rhizobium etli strain CE-3 were used. The results showed the collapse of the infected zone, degradation of the cell walls and membranes,
changes in the n...
Contexts in source publication
Context 1
... 72, respec- tively (Fig. 2). Maximum nodule fresh weight was reached 10 weeks after inoculation in the Bayomex cultivar and 9 weeks in the Cacahuate 72 cultivar. Nodule formation began within 1 day of bacterial inoculation. There were no differences in the structure of nodules between Bayomex and Cacahuate 72, so only those of Bayomex are given (Fig. 3). This shows a transverse section of a 3-week-old mature nodule of cultivar Bayomex in which typical structures such as the cortex (formed by the internal part of the peridermis), the parenchyma, the vascular bundles, and the development zone (which includes endodermis) and internal cortex of infected and non-infected cells. The most ...
Context 2
... of cultivar Bayomex in which typical structures such as the cortex (formed by the internal part of the peridermis), the parenchyma, the vascular bundles, and the development zone (which includes endodermis) and internal cortex of infected and non-infected cells. The most conspicuous changes during symbiosis were found in the development zone (Fig. 3d) and the internal cortex, which contains cells infected by R. etli CE-3 ( Fig. 3f) and also non-infected cells (Fig. 3g). The peridermis showed almost no change from weeks 1 to 10 (Fig. 3a). Changes in color and turgor started in the seventh week. No differences in internal morphology were observed between both cultivars during nodular ...
Context 3
... the internal part of the peridermis), the parenchyma, the vascular bundles, and the development zone (which includes endodermis) and internal cortex of infected and non-infected cells. The most conspicuous changes during symbiosis were found in the development zone (Fig. 3d) and the internal cortex, which contains cells infected by R. etli CE-3 ( Fig. 3f) and also non-infected cells (Fig. 3g). The peridermis showed almost no change from weeks 1 to 10 (Fig. 3a). Changes in color and turgor started in the seventh week. No differences in internal morphology were observed between both cultivars during nodular senes- cence. In the first week, the zone with infected cells was small (white ...
Context 4
... the parenchyma, the vascular bundles, and the development zone (which includes endodermis) and internal cortex of infected and non-infected cells. The most conspicuous changes during symbiosis were found in the development zone (Fig. 3d) and the internal cortex, which contains cells infected by R. etli CE-3 ( Fig. 3f) and also non-infected cells (Fig. 3g). The peridermis showed almost no change from weeks 1 to 10 (Fig. 3a). Changes in color and turgor started in the seventh week. No differences in internal morphology were observed between both cultivars during nodular senes- cence. In the first week, the zone with infected cells was small (white arrow) and the parenchyma still had many ...
Context 5
... includes endodermis) and internal cortex of infected and non-infected cells. The most conspicuous changes during symbiosis were found in the development zone (Fig. 3d) and the internal cortex, which contains cells infected by R. etli CE-3 ( Fig. 3f) and also non-infected cells (Fig. 3g). The peridermis showed almost no change from weeks 1 to 10 (Fig. 3a). Changes in color and turgor started in the seventh week. No differences in internal morphology were observed between both cultivars during nodular senes- cence. In the first week, the zone with infected cells was small (white arrow) and the parenchyma still had many cell (Fig. 4a). During week 2 and 3, the infected zone of the nodule ...
Similar publications
Carioca beans (Phaseolus vulgaris L.) stored under high temperature and humidity are subjected to the hard-to-cook phenomenon (HTC), which result in loss of technological and sensory quality. Cotyledon cells of easy-to-cook (ETC) and HTC bean were examined by histochemical and transmission electron microscopy methods to identify structural differen...
Citations
... This may be due to the fact that broad beans are more adaptable to their environment and that low temperatures and dry conditions are more favorable for nodulation. This is contrary to the findings of Lumactud et al (Fernańdez-Luque et al., 2008;Beleń et al., 2015). This may have occurred because of the different crop species studied; broad bean has a longer root system, greater volume and surface area, greater ability to draw water and nutrients, greater ability to cope with drought, and a lower effect on nodulation (Rowse and Goodman, 1981;Nyalemegbe and Kenneth, 1994). ...
Introduction
Biological nitrogen fixation (BNF) plays a crucial role in nitrogen utilization in agroecosystems. Functional characteristics of plants (grasses vs. legumes) affect BNF. However, little is still known about how ecological zones and cropping patterns affect legume nitrogen fixation. This study’s objective was to assess the effects of different cropping systems on aboveground dry matter, interspecific relationships, nodulation characteristics, root conformation, soil physicochemistry, BNF, and nitrogen transfer in three ecological zones and determine the main factors affecting nitrogen derived from the atmosphere (Ndfa) and nitrogen transferred (Ntransfer).
Methods
The ¹⁵N labeling method was applied. Oats (Avena sativa L.), forage peas (Pisum sativum L.), common vetch (Vicia sativa L.), and fava beans (Vicia faba L.) were grown in monocultures and mixtures (YS: oats and forage peas; YJ: oats and common vetch; YC: oats and fava beans) in three ecological regions (HZ: Huangshui Valley; GN: Sanjiangyuan District; MY: Qilian Mountains Basin) in a split-plot design.
Results
The results showed that mixing significantly promoted legume nodulation, optimized the configuration of the root system, increased aboveground dry matter, and enhanced nitrogen fixation in different ecological regions. The percentage of nitrogen derived from the atmosphere (%Ndfa) and percentage of nitrogen transferred (%Ntransfer) of legumes grown with different legume types and in different ecological zones were significantly different, but mixed cropping significantly increased the %Ndfa of the legumes. Factors affecting Ndfa included the cropping pattern, the ecological zone (R), the root nodule number, pH, ammonium-nitrogen, nitrate-nitrogen, microbial nitrogen mass (MBN), plant nitrogen content (N%), and aboveground dry biomass. Factors affecting Ntransfer included R, temperature, altitude, root surface area, nitrogen-fixing enzyme activity, organic matter, total soil nitrogen, MBN, and N%.
Discussion
We concluded that mixed cropping is beneficial for BNF and that mixed cropping of legumes is a sustainable and effective forage management practice on the Tibetan Plateau.
... The nodules of legumes are of particular interest for the scientific community, as the site of nitrogen fixation by means of symbiotic nitrogen-fixing bacteria. Root nodules of legumes are the product of a highly specific interaction between the bacteria involved (rhizobia) and plants' roots or stems [58]. The inverse correlations observed between yield, pod size, and number of nodules are interesting. ...
The use of beneficial microorganisms, such as plant growth promoting rhizobacteria (PGPR) and mycorrhizal fungi, for organic farming could improve the productivity and the resilience of vegetable crops. Both PGPR and PGPF are allowed for organic farming, and they represent new important tools for regenerating poor and marginal soils in transition to environmentally friendly farming. In the experiment, the effects of PGPM-based products were evaluated on snap bean in combination with two irrigation regimes. The experimental design adopted was split-plot, with the main plot represented by the irrigation regime (reintegration of 100 and 60% of the ETc), the sub-plot by the microbial consortia, and finally the sub-sub-plot by genotype (‘Domino’ and ‘Maxi’). Seeds were sown in a cold greenhouse and the growing cycle finished after 86 days from sowing. The results showed a significant increase of the yield due to the application of PGPM compared to the control. The deficit irrigation applied (ETc 60%) affected plants growth in the two genotypes and their related production differently (in average 2.20 kg m−2 for Domino and 3.63 kg m−2 for Maxi), showing a positive effect of PGPM on yield (in average 2.47 kg m−2 without PGPM and 3.36 kg m−2 with PGPM) and product quality. Furthermore, an interesting negative correlation between the number of nodules and the yield was also observed, as a consequence of their early outcome which increased plant productivity in relation to the experimental factors.
... Highyielding soybeans produce sufficient nodules and increase biological nitrogen fixation capacities. It is reported that nodule numbers were significantly decreased under severe drought stress, resulting in a change in the normal growth of roots (Fernandez-Luquen et al., 2008; Marquez-Garcia et al., 2015) [23,41] . Furthermore, Manavalan et al. (2009) [40] reported that nitrogenase activity was reduced (70%) at the first four days of drought. ...
Soybean is a drought-sensitive crop and drought is one of the serious problems for crop production in many regions of the world, leading to a huge production loss. Drought stress affects soybean growth as well as yield by reducing all yield components and deteriorating the quality of seed. Therefore, crop growth, yield, and quality improvement under drought is an important goal of plant science research. In this review, we will discuss the currently available information on changes in phenology, yield components, and quality of seed under drought stress. It is presumed that this review will help in formulating future research by understanding the physio-morphological changes of soybean under drought stress.
... Due to their ability to form root nodules, i.e., symbiotic association with soil rhizobial bacteria, legumes represent one of the most drought-responsive crop plants. Indeed, as osmotic stress disrupts cellular ionic and osmotic equilibrium [11], nodules are known to be highly sensitive to osmotic stress [12]. Reduced soil water potential (Ψ w ) also affects diffusion of oxygen via the root epidermis, directly affecting the nodule function [13]. ...
Drought dramatically affects crop productivity worldwide. For legumes this effect is especially pronounced, as their symbiotic association with rhizobia is highly-sensitive to dehydration. This might be attributed to the oxidative stress, which ultimately accompanies plants’ response to water deficit. Indeed, enhanced formation of reactive oxygen species in root nodules might result in up-regulation of lipid peroxidation and overproduction of reactive carbonyl compounds (RCCs), which readily modify biomolecules and disrupt cell functions. Thus, the knowledge of the nodule carbonyl metabolome dynamics is critically important for understanding the drought-related losses of nitrogen fixation efficiency and plant productivity. Therefore, here we provide, to the best of our knowledge, for the first time a comprehensive overview of the pea root nodule carbonyl metabolome and address its alterations in response to polyethylene glycol-induced osmotic stress as the first step to examine the changes of RCC patterns in drought treated plants. RCCs were extracted from the nodules and derivatized with 7-(diethylamino)coumarin-3-carbohydrazide (CHH). The relative quantification of CHH-derivatives by liquid chromatography-high resolution mass spectrometry with a post-run correction for derivative stability revealed in total 194 features with intensities above 1 × 105 counts, 19 of which were down- and three were upregulated. The upregulation of glyceraldehyde could accompany non-enzymatic conversion of glyceraldehyde-3-phosphate to methylglyoxal. The accumulation of 4,5-dioxovaleric acid could be the reason for down-regulation of porphyrin metabolism, suppression of leghemoglobin synthesis, inhibition of nitrogenase and degradation of legume-rhizobial symbiosis in response to polyethylene glycol (PEG)-induced osmotic stress effect. This effect needs to be confirmed with soil-based drought models.
... Finally, the sections were left in 100% methyl salicylate until microscopy analysis. For staining, vibratome sections were first dehydrated in a graded ethanol series (85, 96, and 100%-1.5 h each) and then stained with Safranin O-Fast Green according to Fernandez-Luqueno et al. (2008). ...
... Longitudinal, 4 or 10 µm thick, sections (depending on the DAA age) were made with an American Optics Spencer 820 Rotary Microtome. Sections were placed on microscope slides, dried at 60°C for at least 1 h, and stained with Safranin O-Fast Green (Fernandez-Luqueno et al., 2008). ...
This work describes the application of clearing on vibratome sections to study the embryo formation in cassava. This procedure provides high-resolution images and reduces significantly the number of sections that need to be analyzed per ovule. This methodology was instrumental for the development of the protocol for embryo rescue in cassava. It has been also applied to monitor the embryo formation response when optimizing seed setting from regular and broad crosses for cassava breeding. Broad crosses between cassava and castor bean (incompatible-euphorbiaceae species) were made aiming to induce doubled haploids through the elimination of the incompatible-male parent genome as done in cereals. Castor bean is widely available and provides continues supply of pollen. Our results suggest that this methodology is easy and effective to assess the response of hundreds of cassava ovules pollinated with castor bean pollen, allowing the identification of multicellular structures in the embryo sac without apparent formation of endosperm. The protocol is also useful when developing and optimizing a methodology to induce doubled haploids in cassava via gynogenesis or from ovules pollinated with irradiated cassava pollen.
... According to Gualtieri and Bisseling (2000), P. vulgaris nodules matured within few weeks and appeared spherical due to non-persistent meristematic characteristics. Fernández-Luqueño et al. (2008) reported that during nodule senescence some morphology changes are taking place in two studied cultivars of P. vulgaris (Bayomex and Cacahuate 72) inoculated with Rhizobium etli strain CE-3. These include a change in protein and starch granules and their distribution, disintegration of central tissues, breakdown of a cell wall, and cellular collapse of infected zone. ...
Legumes (Leguminosae or Fabaceae) are considered the second most cultivated crop, covering 14% of the total cultivated land worldwide. Legumes considered as the major source of important oils, micronutrients, vegetable proteins, fiber, and minerals for both livestock and human consumption. Besides, they provide nitrogen (N) to agroecosystem through their exclusive capability to fix atmospheric N in symbiotic relationship with soil rhizobia. The symbiotic association among legumes and rhizobial bacterium occurs in the root nodules of legume where they access to atmospheric N. Hence, it is of great benefit for us to understand the mechanism of symbiotic nitrogen fixation (SNF) and their effects on the neighboring environment. The excessive application of chemical fertilizers has resulted in an alarming disturbance of the N cycle, e.g., buildup of nitrates in soil and water and atmosphere contamination with nitrogen oxides. In order to maintain a sustainable agricultural system, substitutes for chemical fertilizers should be sought on an emergency basis. Biological nitrogen fixation (BNF), known as a microbiological process, is used by legumes that transform atmospheric N into a plant in its usable form, which can be this alternative. Mineral N shortage is a recurring character of arid and semi-arid soils. Consequently, it is understood that BNF is a sustainable and environmentally friendly substitution to chemical fertilizers. There exists convincing proof that some non-leguminous crops, in some cases, may benefit from association with diazotrophs. Considerably, a natural association between plants mainly gains the potential benefit from N fixation and bacteria, which is seldom manageable as, part of agricultural practices. Especially in drylands, these associations are hard to maintain and are very unreliable. Nonetheless, through recent advancements in induction of nodular structures on roots of several cereal crops, i.e., wheat and rice, the possibility of dependable symbiosis with free-living diazotrophs, e.g., azospirilla and rhizobia may ultimately be achieved. Nevertheless, in this chapter, we have described the biology and physiology of N fixation by legumes.
... Longitudinal, 4 µm or 10 µm thick, sections (depending on ovaries age) were made with an American Optics Spencer 820 Rotary Microtome. Sections were placed on microscope slides, dried at 60 • C for at least 1 h, and then stained with Safranin O -Fast Green (Fernandez-Luqueno et al., 2008). Samples were analyzed under light and dark field illumination with a Nikon Eclipse 55i microscope. ...
Embryo rescue (ER) in cassava breeding has several relevant applications, from the recovery of broad crosses to the recovery of seeds from the standard pollination program. Cassava fruit setting may drop from 100%, during the 1st week after pollination, to less than 40% during the 2nd week after pollination due to the abscission of fruits depending on genotypes. Therefore, the availability of an ER protocol for early stages of embryo development, in particular during the first 2 weeks after pollination (prior the cotyledonary stage), could have practical implications for cassava breeding. Until now, attempts to recover cassava immature embryos at stages of development earlier than the cotyledonary stage failed. The earliest successful rescue reported in cassava is from embryos excised 32–36 days after anthesis (DAA). However, limited information was available regarding embryo development in cassava. This work studied and documented the stage of embryo development in histological sections of hand-pollinated ovules fixed from 1 to 30 days after anthesis (DAA). At 7 DAA, zygotes were just at the first stages of cell division (pro- embryo stage). At 14 DAA, embryos were at the pre-globular stage. Embryos at the early globular stage were observed in sections fixed at 21 DAA, and at the proper globular stage at 24 DAA. Samples at 30 DAA contained cotyledonary embryos that easily developed after ovule culture into viable plants using existing protocols. A second contribution of this work is the development of a protocol for the recovery of fully developed plants from immature embryos rescued and cultured in vitro as early as 7–14 DAA. Since embryos collected at this age are at the pro-embryo to pre-globular stage, ovary/ovule culture was necessary. A method is described whereby ovules were cultured to allow the development of pro-embryos and pre-globular stage embryos into the cotyledonary stage. Subsequently, these mature embryos were excised from the ovules to induce germination and the recovery of fully developed plants.
... Longitudinal 4-µm-or 8-10-µm-thick sections (depending on the age of the ovaries) were made with an American Optics Spencer 820 Rotary Microtome. The sections were placed on microscopic slides, dried at 60 • C for at least 1 h, and then stained with Safranin O-Fast Green (Fernandez-Luqueno et al., 2008). The samples were analyzed under light and dark field illumination with a Nikon Eclipse 55i microscope. ...
Cassava (Manihot esculenta Crantz) is an important crop for subsistence farming in tropical and subtropical regions. There is a need to increase the rate of genetic gain to develop varieties adapted to new environmental conditions affected by climate change, which also influences the patterns of pests and diseases. The rate of cassava genetic improvement is limited by the difficulty in obtaining true-breeding types (inbred/homozygous lines). Cassava inbreeding obtained through conventional sequential self-pollination increases exposure of useful recessive traits and breeding value of progenitors. However, it takes 10–15 years to produce homozygous lines through successive self-pollination. Doubled haploid (DH) technology is a functional alternative to progressive self-pollination, and is already widely used in major crops to accelerate inbreeding. This work aimed at developing a protocol for the culture of isolated ovules and the induction of gynogenesis in cassava. Basic groundbreaking studies on cassava embryo sac development are presented. A protocol using unpollinated ovules collected from ovaries 1 day after anthesis is described. In the unpollinated-cultured ovules, the presence of embryos formed probably from the egg cells and not surrounded by the endosperm, was documented by anatomical analyses. This achievement is an important first step in the development of a reproducible gynogenesis protocol for the generation of doubled haploids in cassava. This protocol can also be useful as a starting point to obtain DHs using alternative methods of induction such as pollination of cassava with pollen of distant species or with cassava pollen irradiated with gamma rays.
... Inmediatamente después de la siembra se aplicó un riego con agua de la llave. Durante el cultivo del frijol se realizaron riegos con agua potable según las necesidades del cultivo, así como con riegos adicionales con 250 mL de solución nutritiva una vez a la semana (Fernández-Luqueño et al., 2008). A los 15 días después de la siembra (DDS) se realizó un raleo para dejar solo una plantas por UE. ...
... Identification of genes, proteins, and metabolites involved in the formation of specific resistant features in plants are essential for better understanding of root architecture regulation, bacteroid development and lifespan concerning an adaptation of legumes to grow in conditions of water deficiency. Studies carried out on Glycine max, Medicago truncatula, Medicago sativa, Pisum sativum, Phaseolus, Lotus japonicus and Trifolium repens showed that drought adversely affects number, size, and density of nodules, and consequently disturbs their functioning (Fernández-Luqueño et al., 2008;Suárez et al., 2008;Márquez-Garcia et al., 2015). In the first stage, we analyzed the basic biometric parameters and made microscopy studies to demonstrate the influence of drought stress on plants and confirm the choice of this experimental approach. ...
The ability of symbiosis with Rhizobium bacteria is an extremely important trait of Lupinus luteus L. Its cultivation increases soil fertility and reduces the necessity of using chemical fertilizers, thus makes lupine an excellent proecological and agronomical species. Nevertheless, nodule functioning associated with nitrogen fixation can be strongly affected by soil drought. On the face of changing climatic conditions, the emphasis should be given to get the knowledge concerning the phytohormonal and molecular markers of early response on water deficit in soil. In this paper, we have shown that soil drought stress, by causing water loss in nodules and affecting their structure, evokes degradation of symbiosome and leads to hormonal and molecular changes. The stress factor modulated abscisic acid (ABA) and ethylene (ET) biosynthesis pathways. It was reflected by increased expression of LlZEP (ZEAXANTHIN EPOXIDASE) involved in ABA biosynthesis and strong accumulation of this phytohormone. At the same time, the mRNA of synthase (LlACS) and oxidase (LlACO) of 1-aminocyclopropane-1-carboxylic acid (ACC) were elevated, while ACC accumulated significantly. Moreover, drought stress negatively influenced the expression of LlBOP (BLADE-ON-PETIOLE) and LlLbI (LEGHEMOGLOBIN), previously pointed out as regulators of nodule functioning. Simultaneously the iron and nitrogen content drastically decreased in the stressed nodules. Presented novel information describing phytohormonal changes during drought stress directly in the nodules can help to elucidate the hormonal and molecular mechanisms that control plant response to water loss.
