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The effect of auxin transport inhibition on Arabidopsis root development at low and high phosphate. Arabidopsis (Col-0) seedlings were grown for 16 d on nutrient medium containing low (1 M) and high (1 mM) phosphate content and varying concentrations of TIBA. Data are given for the length of the primary root (A), lateral root number (B), and lateral root density (C). Values shown represent the mean of 15 seedlings SE. Different letters are used to indicate means that differ significantly (P 0.05).
Source publication
The postembryonic developmental program of the plant root system is plastic and allows changes in root architecture to adapt to environmental conditions such as water and nutrient availability. Among essential nutrients, phosphorus (P) often limits plant productivity because of its low mobility in soil. Therefore, the architecture of the root syste...
Contexts in source publication
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... this effect appeared to be more dras- tic in low P conditions: Primary root elongation de- creased 2-fold in low P-treated seedlings grown in the presence of 10 7 m TIBA when compared with untreated controls, whereas a significant reduction of primary root elongation in seedlings grown at 1 mm P was only observed at concentrations of 10 5 m TIBA (Fig. 4A). Lateral root formation was similarly affected by treatments with 10 7 m TIBA at both high and low P concentrations, 41% and 50%, respectively (Fig. 4B). However, lateral root formation was completely abolished at 10 6 m TIBA in seedlings grown in 1 mm P, whereas at this concentration seedlings grown at low P still produce several ...
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... of 10 7 m TIBA when compared with untreated controls, whereas a significant reduction of primary root elongation in seedlings grown at 1 mm P was only observed at concentrations of 10 5 m TIBA (Fig. 4A). Lateral root formation was similarly affected by treatments with 10 7 m TIBA at both high and low P concentrations, 41% and 50%, respectively (Fig. 4B). However, lateral root formation was completely abolished at 10 6 m TIBA in seedlings grown in 1 mm P, whereas at this concentration seedlings grown at low P still produce several lateral roots (Fig. 4B). As a consequence of these changes, the negative effect of TIBA on lateral root density at 1 m P is significantly lower than at 1 mm ...
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... Lateral root formation was similarly affected by treatments with 10 7 m TIBA at both high and low P concentrations, 41% and 50%, respectively (Fig. 4B). However, lateral root formation was completely abolished at 10 6 m TIBA in seedlings grown in 1 mm P, whereas at this concentration seedlings grown at low P still produce several lateral roots (Fig. 4B). As a consequence of these changes, the negative effect of TIBA on lateral root density at 1 m P is significantly lower than at 1 mm P (Fig. ...
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... (Fig. 4B). However, lateral root formation was completely abolished at 10 6 m TIBA in seedlings grown in 1 mm P, whereas at this concentration seedlings grown at low P still produce several lateral roots (Fig. 4B). As a consequence of these changes, the negative effect of TIBA on lateral root density at 1 m P is significantly lower than at 1 mm P (Fig. ...
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... to be essential for lateral root development ( Reed et al., 1998;Casimiro et al., 2001). We used TIBA, an auxin transport inhibitor, to gain knowledge of the participation of auxin trans- port on lateral root development in response to P availability. Primary root elongation in low P seed- lings was more sensitive to TIBA than in high P seedlings (Fig. 4A); however, P-deprived plants showed lower sensitivity to the negative effect of TIBA on lateral root formation and lateral root den- sity when compared with high P-grown plants (Fig. 4, B and C). Because it is known that auxins inhibit primary root elongation and stimulate lateral root formation, these observations appear somewhat par- ...
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... port on lateral root development in response to P availability. Primary root elongation in low P seed- lings was more sensitive to TIBA than in high P seedlings (Fig. 4A); however, P-deprived plants showed lower sensitivity to the negative effect of TIBA on lateral root formation and lateral root den- sity when compared with high P-grown plants (Fig. 4, B and C). Because it is known that auxins inhibit primary root elongation and stimulate lateral root formation, these observations appear somewhat par- adoxical. However, it has recently been reported that treatment with auxin transport inhibitors results in suboptimal levels of auxins for lateral root initiation, but also in the ...
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Citations
... Generally, highly weathered soils under humid tropical environments show low fertility, high acidity, and high iron (Fe) and aluminum (Al) oxide contents. In these soils, the movement of the H 2 PO 4 ion, the main form of phosphorus (P) taken up by plants, is very slow due to physical-chemical mechanisms binding it to the colloid surface, which is more evident in tropical soils (López-Bucio et al., 2002). When low-P soils are first fertilized, farmers must apply more P than what is taken up by crops, but continuous phosphate application gradually saturates the pathways through which phosphate is adsorbed and penetrates in soil colloids (Barrow & Debnath, 2014). ...
Background
Most of the phosphorus (P) applied to low fertility, acidic tropical soils with high iron and aluminum oxide contents end up adsorbed to soil colloids and not available to crops. Diffusion of P from fertilizers was found to be facilitated by coating with humic substances and by soil moisture.
Aim
However, there is still controversy on the effect of humic substances on soil P forms and diffusion, and there is a gap in the knowledge of how coating the fertilizer interacts with soil water.
Methods
We studied P diffusion and availability from a conventional single superphosphate and a humic acid‐coated superphosphate in Petry dishes as affected by soil moisture and the effect of the distance of the fertilizer to the roots using a root‐matt methodology.
Results
Coating single superphosphate with humic substances from leonardite (0.5%) and increasing water moisture resulted in improved P diffusion in the soil and plant P uptake. Maize dry matter increased by humic acid‐coated phosphate from 3% to 26%, depending on the distance from the fertilizer to the roots. Therefore, there is evidence of a lower P adsorption to soil colloids. The coated fertilizer increased labile P by 76% around the fertilizer granule, while higher levels of less labile P were observed with the use of conventional single superphosphate.
Conclusion
All this resulted in facilitated P transport from the soil to the roots, which is important mainly in double‐cropped systems where the second crop is usually exposed to temporary drought.
... In particular, although BB consistently showed increased LR density with increasing P availability, the cultivar Okinawa showed increased LR density with decreasing P (Villordon et al. 2020). For Arabidopsis, it has been demonstrated that LR density can vary depending on available P in the growth medium (L opez-Bucio et al. 2002;Williamson et al. 2001). ...
The primary objective of this work was to generate species-specific information about root architectural adaptations to simulated natural levels of arsenic (As) during the establishment phase and onset of storage root formation in sweetpotato. Cultivars Bayou Belle and Beauregard were grown on sand substrate and provided with 0.5X Hoagland’s nutrient solution with varying levels of As (0, 5, 10, or 15 mg⋅L ⁻¹ ). During the first experiment, entire root systems were sampled at 5, 10, and 15 days, corresponding to key adventitious root developmental stages. Compared with the untreated controls at 15 days, ‘Bayou Belle’ and ‘Beauregard’ provided with 15 mg⋅L ⁻¹ As showed respective increases in the following root architectural attributes: 168% and 130% in main root length; 168% and 98% in lateral root length; and 140% and 50% in lateral root density. A second experiment was performed to produce storage root samples at 50 days. Storage root length, width, and length/width ratio did not vary with As levels. The accumulation of As in storage roots increased with increasing As levels. The results support the hypothesis that natural As levels stimulate adventitious root development in sweetpotato in a cultivar-dependent manner. The observations are consistent with findings of other species that show similar growth stimulation at low As levels. This is the first report of sweetpotato root system architecture responses to experimental levels of As that are known to be present in agricultural soils. Standardization of experimental procedures and understanding of root system adaptations to natural levels of As could lead to a more systematic exploitation of genome-wide techniques and characterization of the molecular basis of reduced As uptake in plants.
... Auxin is an important phytohormone that promotes plant LR growth and development, and Pi can regulate LR development by altering auxin biosynthesis, signal transduction, polar transport and sensitivity Nacry et al., 2005;Perez-Torres et al., 2008). Studies have shown that the concentration of auxin increases in both whole taproots and new LRs of Arabidopsis thaliana but decreases in old LRs under a low-Pi environment (Jiang et al., 2007;Lopez-Bucio et al., 2002;Nacry et al., 2005). In addition, auxin in maize (Zea mays) is redistributed under Hetero-NP or Hetero-LP conditions, thereby regulating root morphology (Wang et al., 2020). ...
... Phytohormones such as IAA, ABA and GA are known to play important roles in regulating RSA under low Pi stress (Jia et al., 2022;Kumar et al., 2021;Liu, 2021). Auxin is considered to be the main regulator of LR development, promotes the differentiation of LR primordial cells and regulates the morphogenesis of LRs (Jiang et al., 2007;Liu et al., 2013;Liu, 2021;Lopez-Bucio et al., 2002;Nacry et al., 2005;Wang et al., 2020). In the present study, the difference in auxin concentration between the Hetero-NP and Hetero-LP treatments may be because the supply of heterogeneous Pi promotes the redistribution of auxin, which participates in the regulation of the development of LRs. ...
... Under low P stress, the concentrations of phytohormones such as IAA, ABA, JA, SA and GA change, and the levels of genes involved in phytohormone synthesis, signal transduction, response and metabolism also increase . Several key elements of the auxin pathway play important roles in LR proliferation in response to low P stress in A. thaliana, such as PIN, ARF, AUX/IAA, LBD, GH3, small auxin-up RNAs (SAUR), and the auxin receptor TIR1 (Lopez-Bucio et al., 2002;Okushima et al., 2007;Perez-Torres et al., 2008;Scheible and Rojas-Triana, 2015). In this study, the transcription level of ILL6 (potri.002g082400), ...
... For the coordination of auxin and phosphate signalling, specifically the formation of lateral roots in response to low P i , genes encoding MYB-CC domains, including PHR1, were also found to be targets of ARF TFs [81]. The fact that PSR was suppressed in auxin repressor iaa28-1 mutant would also suggest that some ARFs act as suppressors of PHR1or related CC-MYC [137]. Huang et al. [81] found that the binding of ARF7 and ARF19 to auxin-response elements of the PHR1 promoter is essential for the induction of PSI genes under low P i availability, and phosphate uptake was reduced when ARF7 and ARF19 function was abolished. ...
The plant macronutrient phosphorus is a scarce resource and plant-available phosphate is limiting in most soil types. Generally, a gene regulatory module called the phosphate starvation response (PSR) enables efficient phosphate acquisition by roots and translocation to other organs. Plants growing on moderate to nutrient-rich soils need to co-ordinate availability of different nutrients and repress the highly efficient PSR to adjust phosphate acquisition to the availability of other macro- and micronutrients, and in particular nitrogen. PSR repression is mediated by a small family of single SYG1/Pho81/XPR1 (SPX) domain proteins. The SPX domain binds higher order inositol pyrophosphates that signal cellular phosphorus status and modulate SPX protein interaction with PHOSPHATE STARVATION RESPONSE1 (PHR1), the central transcriptional regulator of PSR. Sequestration by SPX repressors restricts PHR1 access to PSR gene promoters. Here we focus on SPX4 that primarily acts in shoots and sequesters many transcription factors other than PHR1 in the cytosol to control processes beyond the classical PSR, such as nitrate, auxin, and jasmonic acid signalling. Unlike SPX1 and SPX2, SPX4 is subject to proteasomal degradation not only by singular E3 ligases, but also by SCF–CRL complexes. Emerging models for these different layers of control and their consequences for plant acclimation to the environment will be discussed.
... One common strategy plants employ for increasing P-uptake is the production of longer and more branched roots, which can increase the surface area of the root system and improve the plant's ability to explore the soil for nutrients. For example, several studies have shown that plants grown under low P-conditions produce longer and more branched roots than those grown under high P-conditions [60,61]. ...
Soil phosphorus (P) plays a crucial role in regulating plant-microbe interactions in the rhizosphere. This chapter provides an in-depth analysis of the role of P in plant physiology, growth, and its availability in soil. Phosphorus acquisition and uptake, its impact on plant metabolism, and its influence on plant growth and development are reviewed in this chapter. The mechanisms by which plants acquire P from the soil, including the production of phosphatase enzymes, secretion of organic acids, mycorrhizal symbiosis, changes in root morphology, phosphorus use efficiency, and mobilization and transporters, are also reviewed. The chapter also explores the impact of P on microbial communities in the rhizosphere and its role in plant-microbe interactions. Finally, the implications of P availability in the rhizosphere for sustainable agriculture and crop production are discussed, highlighting the potential for improving P availability in the soil to enhance agricultural productivity and environmental sustainability.
... Phosphorus deficiency is a limiting factor for plant growth, and a limited amount of plant-available soil phosphorous leads to severe yield losses [44]. Phosphorus deficiency causes a decrease in the number of primary roots and an increase in lateral root density and length [45][46][47][48]. Alfin-like transcription factor AL6 pure mutants produced shorter root hairs under phosphorus deficiency conditions, probably caused by altered expression of its downstream target genes. ...
Alfin-like (AL) proteins are an important class of transcription factor (TF) widely distributed in eukaryotes and play vital roles in many aspects of plant growth and development. AL proteins contain an Alfin-like domain and a specific PHD-finger structure domain at the N-terminus and C-terminus, respectively. The PHD domain can bind to a specific (C/A) CAC element in the promoter region and affect plant growth and development by regulating the expression of functional genes. This review describes a variety of AL transcription factors that have been isolated and characterized in Arabidopsis thaliana, Brassica rapa, Zea mays, Brassica oleracea, Solanum lycopersicum, Populus trichocarpa, Pyrus bretschenedri, Malus domestica, and other species. These studies have focused mainly on plant growth and development, different abiotic stress responses, different hormonal stress responses, and stress responses after exposure to pathogenic bacteria. However, studies on the molecular functional mechanisms of Alfin-like transcription factors and the interactions between different signaling pathways are rare. In this review, we performed phylogenetic analysis, cluster analysis, and motif analysis based on A. thaliana sequences. We summarize the structural characteristics of AL transcription factors in different plant species and the diverse functions of AL transcription factors in plant development and stress regulation responses. The aim of this study was to provide a reference for further application of the functions and mechanisms of action of the AL protein family in plants.
... Вміст органічних речовин, макро-і мікроелементів, води, кисню, а також pH, температура, і наявність патогенних мікроорганізмів у ґрунті 23 значно впливають на кількість, фізіологічний та метаболічний стан мікроорганізмів. Мінеральна добрива -один з чинників, що гальмує ефективність ґрунтових мікроорганізмів 24,25,26 . ...
Економічна і екологічна криза привели до різкого зменшення внесення органічних і мінеральних добрив, зниження площ посівів багаторічних бобових трав, ігнорування сівозмін. Це підсилює деградацію ґрунтів, активує процес дегуміфикації та переущільнення ґрунтів, знижуючи інтенсивність біологічного кругообігу, що негативно позначається на ефективності їх родючості і врожайності вирощуваних культур. Метою роботи було визначити особливості морфологічних ознак кореневої системи селекційного матеріалу люцерни, встановити кореляційні зв’язки ознак кореневої системи та надземної маси.
Виділити кращі генотипи для використання їх у практичній селекції.
У розділі монографії наведено результати дослідження морфологічних особливостей кореневої системи та її зв’язку з травостою у різних генотипів люцерни, представлених сортами та популяціями: Луїза, Зоряна, Надія, Унітро, Серафима, ПК/98, ПР-04, МО-115, SV, НМG.
Дослідження проводили протягом 2015–2018 рр. в польових умовах в Інституті зрошуваного землеробства НААН на темно-каштановому ґрунті. Технологія вирощування культури була стандартною для зрошуваних умов зони проведення досліджень. Експериментальні дані обробляли за загальноприйнятою методикою дисперсійного аналізу та кореляційного аналізу Пірсона. Результати дослідження свідчать про суттєві відмінності морфології кореневої системи в різних генотипів люцерни та їх неоднакове значення для селекційної роботи. Сорти Зоряна, Серафим та популяція МО-115 з високим об’ємом кореневої системи 6,9–7,0 мл та встановленими зв’язками між вивченими особли- востями кореневою та надземною масою рекомендовано використо- вувати в подальшій селекційній роботі люцерни. При вивченні морфо- логічної структури кореневої системи було встановлено, що діаметр головного кореня, залежно від генотипу, в абсолютному вираженні, знаходиться в межах 5,10–7,80 мм, при амплітуді коливання коефіцієнту варіювання V=26,4–31,4 %, що дає можливість передбачити ефективний добір за цією ознакою. У доборів за діаметром головного кореня у більшості генотипів підвищуються показники продуктивності надземної та кореневої маси чи одного з них. При збільшенні діаметра до 6,7–6,9 мм, після другого циклу доборів, підвищується продуктивність надземної маси до 4,75–6,37 г, кореневої – до 4,71–5,26 г.
... The vigor of the parent plant, combined with balanced nutrition, can positively induce the rhizogenesis of the cuttings, defining the concentration of carbohydrates, nitrogenous substances, amino acids, auxins, phenolic compounds, among other rooting promoting substances (López-Bucio et al., 2002;Cunha et al., 2009). Cunha et al. (2009) describe in Table 1 the macro and micronutrient demands in Eucalyptus globulus during root formation of woody species. ...
Guarana [Paullinia cupana var. sorbilis (Mart.) Ducke] is a species of great economic and social important in Brazil, as it is the only commercial guarana producer in the world. The vegetative propagation method indicated for the culture is stem cuttings, which aims at productivity, tolerance, and uniformity of clonal cultivars, because
reproduction by seeds has slow germination and high genetic variability, which in traditional varieties is an undesirable factor. Genetic factors can interfere with the rooting capacity of the crop. Studies seek alternatives that can improve this condition and enhance the production system. Use of growth regulators, microorganisms that promote plant growth, variation of substrates and fertilization, have been strategies used. Preliminary tests on the rate of stem rooting and seed germination with the use of exogenous phytohormone did not demonstrate in relation to the non-application of these inducers. The use of rhizobacteria, which presents itself as a promising activity in many cultures, has not yet been demonstrated in the culture of guarana. On the other hand, the influence of different substrates on rooting has already shown consistent results as a function of rooting rate. Fertilizing the mother plants as recommended by the production system for the crop has proven to be an efficient procedure. There are still few studies aimed at improving the spread of guarana, demonstrating that new protocols need to
be explored, or that the protocols already used are reviewed from another perspective.
... Sterile plant seeds are germinated and grown under sterile conditions at 22 • C with a photoperiod of 16 h of light and 8 h of darkness [117]. Five-to ten-day-old seedlings are inoculated with a bacterial culture, with uninoculated plants used as controls. ...
This review covers the literature data on plant growth-promoting bacteria in soil, which can fix atmospheric nitrogen, solubilize phosphates, produce and secrete siderophores, and may exhibit several different behaviors simultaneously. We discuss perspectives for creating bacterial consortia and introducing them into the soil to increase crop productivity in agrosystems. The application of rhizosphere bacteria—which are capable of fixing nitrogen, solubilizing organic and inorganic phosphates, and secreting siderophores, as well as their consortia—has been demonstrated to meet the objectives of sustainable agriculture, such as increasing soil fertility and crop yields. The combining of plant growth-promoting bacteria with mineral fertilizers is a crucial trend that allows for a reduction in fertilizer use and is beneficial for crop production.
... Another phenomenon worth mentioning is that the number and density of lateral roots were reduced to varying degrees on all three media (Fig. 1e-f ). Compared to the previous report that Pi-limiting conditions arrests primary root growth and promotes lateral root proliferation in Arabidopsis plants [34], our work revealed that during a largescale shortage of mineral nutrients, plants could divert their limited resources from lateral root growth and development, and the adaptation strategy focused mainly on primary roots and root hairs. ...
Background
Plants show developmental plasticity with variations in environmental nutrients. Considering low-cost rock dust has been identified as a potential alternative to artificial fertilizers for more sustainable agriculture, the growth responses of Arabidopsis seedlings on three rock meals (basalt, granite, and marlstone) were examined for the different foraging behavior, biomass accumulation, and root architecture.
Results
Compared to ½ MS medium, basalt and granite meal increased primary root length by 13% and 38%, respectively, but marlstone caused a 66% decrease, and they all drastically reduced initiation and elongation of lateral roots but lengthened root hairs. Simultaneous supply of organic nutrients and trace elements increased fresh weight due to the increased length of primary roots and root hairs. When nitrogen (N), phosphorus (P), and potassium (K) were supplied individually, N proved most effective in improving fresh weight of seedlings growing on basalt and granite, whereas K, followed by P, was most effective for those growing on marlstone. Unexpectedly, the addition of N to marlstone negatively affected seedling growth, which was associated with repressed auxin biosynthesis in roots.
Conclusions
Our data indicate that plants can recognize and adapt to complex mineral deficiency by adjusting hormonal homeostasis to achieve environmental sensitivity and developmental plasticity, which provide a basis for ecologically sound and sustainable strategies to maximize the use of natural resources and reduce the production of artificial fertilizers.
