Boron Deficiency Research Articles

Addition of silicon to boron foliar spray in cotton plants modulates the antioxidative system attenuating boron deficiency and toxicity

BackgroundBoron (B) nutritional disorders, either deficiency or toxicity, may lead to an increase in reactive oxygen species production, causing damage to cells. Oxidative damage in leaves can be attenuated by supplying silicon (Si). The aim of this study was to assess the effect of increasing foliar B accumulation on cotton plants to determine whether adding Si to the spray solution promotes gains to correct deficiency and toxicity of this micronutrient by decreasing oxidative stress via synthetizing proline and glycine-betaine, thereby raising dry matter production.ResultsB deficiency or toxicity increased H2O2 and MDA leaf concentration in cotton plants. H2O2 and MDA leaf concentration declined, with quadratic adjustment, as a function of increased leaf B accumulation. Proline and glycine-betaine leaf concentration increased under B-deficiency and B-toxicity. In addition, production of these nonenzymatic antioxidant compounds was greater in plants under toxicity, in relation to deficient plants. Adding Si to the B spray solution reduced H2O2 and MDA concentration in the plants under nutrient deficiency or toxicity. Si reduced H2O2, primarily in B-deficient plants. Si also increased proline and glycine-betaine concentration, mainly in plants under B toxicity. Dry matter production of B-deficient cotton plants increased up to an application of 1.2 g L− 1 of B. The critical B level in the spray solution for deficiency and toxicity was observed at a concentration of 0.5 and 1.9 g L− 1 of B, respectively, in the presence of Si, and 0.4 and 1.9 g L− 1 of B without it. In addition, the presence of Si in the B solution raised dry matter production in all B concentrations evaluated in this study.ConclusionOur findings demonstrated that adding Si to a B solution is important in the foliar spraying of cotton plants because it increases proline and glycine-betaine production and reduces H2O2 and MDA concentration, in addition to mitigating the oxidative stress in cotton plants under B deficiency or toxicity.

Boron in Soil Plant System and Its Significance in Indian Agriculture

Boron is one of the 17 essential plant nutrients, required for normal plant growth. Its widespread deficiency in ~30% of Indian soils have been observed to affect plant growth and economic yield. Because of its mobile nature, it tends to leach down in soil layers. Boron deficiency has more specifically been observed in light-textured alluvial soils with low content of organic matter. The higher active absorptive surface area of clays restricts its leaching losses. Boron becomes available to plants upon decomposition of organic matter by soil micro-organisms after its mineralization. The soils with high content of calcium carbonate are also prone to B deficiency. Boron availability decreases with an increase in soil pH, except in saline-sodic soils. Soil application of B has been observed to more credible option owing to its considerable residual effect on succeeding crops. Considerable yield response of B application has been found in cotton, cereals, legumes, oilseeds and alfalfa and citrus fruit plants, grown in B deficient soils. Therefore, assessment of B status in soils is crucial to ensure B application in deficient soils for the long-term sustainability of soils in terms of exploring crop genetic potential. Boron is a critical nutrient from a nutritional requirement point of view as it shows second most widespread micronutrient deficiency globally after Zn.

Diagnosis of Boron Deficiency and Effects of Boron on Yield and Quality Values of Sugar Beet (Beta vulgaris L.) Grown in Elbistan District

Diagnosis of Boron Deficiency and Effects of Boron on Yield and Quality Values of Sugar Beet (Beta vulgaris L.) Grown in Elbistan District

The Influence of Boron on Some Plant Nutrients in Sweet Sorghum (Sorghum bicolor L.)

Boron is one of the important micronutrients which plays important role in plant growth. The supply of boron to the plants plays key role in behaviour of other macro and micro nutrients in the plant. The response of plants to boron varies with soil type, environmental conditions and plant species also. So, the excess or deficiency of boron may affect the uptake and availability of other plant nutrients. The sweet Sorghum is important crop used as food, fodder, fuel and fertilizer. It can produce sugar juice from the stem that is useful to produce ethanol, jaggery and syrup along with grains. The sweet Sorghum c. v. Madhura and RSSV-9 were selected for the present investigation. The seeds of these varieties were sown in the earth pots having 2x3x2 feet in size and depth. An average of 25 kg of black soil was used with average 2 kg of organic farm manures per pot. The selected soil was analysed for its original boron concentration. The soil is having 0.0339 ppm boron in it with p H 6.7. After 15 days, 40 days and 70 days of sowing, the pots were treated with different boron concentrations like 10 ppm, 50 ppm and 100 ppm along with control having distilled water only. Five fresh leaf samples were collected randomly on the 5 th day of last boron treatment and washed with distilled water for further analysis. In the present investigation an attempt has been made to study the behaviour of inorganic contents like magnesium and manganese in sweet sorghum cultivars Madhura and RSSV-9 after treating with different boron concentrations. The results are showing consistent decrease in magnesium content due to all the boron treatments in both the cultivars but significant decrease in Mg content reported with 100 ppm boron in c. v. Madhura. The manganese activity is increased due to 10 ppm boron treatment in both the varieties. As boron treatment is increased the Mn level is decreased as compare to control plants in both cultivars under investigation.

Growth, Gas Exchange, and Boron Distribution Characteristics in Two Grape Species Plants under Boron Deficiency Condition

The boron (B) deficiency tolerance capacity of two grape materials, ‘Xishui-4’ (Vitis flexuosa) and ‘Crystal’ (V. vinifera × V. labrusca), were evaluated using a potted experiment in order to identify the B-use efficiency of grape and screen B-efficient grape resources. The sterile lines of two genotypes of grape were used as test materials, and a large number of test-tube seedlings were obtained through rapid propagation. The test-tube seedlings were acclimatization and transplanted, and the tested seedlings were treated with B stress after survival. In this experiment, the materials were cultured in nutrient solution, which contained 0.00 (B0), 0.25 (B1), and 0.50 (control) mg·L−1 B concentrations, and the two genotypes of grape seedlings were cultured in vitro. The results were counted after 60 days of culture. The results showed that the B deficiency significantly reduced the growth parameters such as plant height, leaf area, total root length, and dry biomass of the two genotypes, and the inhibition of ‘Crystal’ growth parameters was greater than that of ‘Xishui-4’. Moreover, the B deficiency also affected photosynthesis of the two genotypes, such as decreased leaf photosynthetic pigments, net photosynthesis rate, transpiration rate, stomatal conductance, intercellular carbon dioxide concentration, and stomatal density. Interestingly, the decrease ranges of ‘Crystal’ were greater than those of ‘Xishui-4’, indicating that ‘Crystal’ photosynthesis was more susceptible to B deficiency. Under the control condition, the concentration and accumulation of B in ‘Crystal’ were significantly higher than those in ‘Xishui-4’. However, under the condition of B deficiency, the B concentration, accumulation amount, accumulation rate, utilization index, and tolerance index of ‘Xishui-4’ were higher than those of ‘Crystal’, and the B transport capacity of ‘Xishui-4’ was more stable, indicating that ‘Xishui-4’ had a better tolerance against B-deficient stress than ‘Crystal’ did. Therefore, ‘Xishui-4’ is a plant with strong adaptability to B deficiency stress, which can be used as B efficient grape resources and a genetic improvement of B efficient grape.

Boron supplying alters cadmium retention in root cell walls and glutathione content in Capsicum annuum

Large areas of farmland in southern China are facing environmental problems such as cadmium (Cd) contamination and boron (B) deficiency. The aim of this study was to investigate the biochemical and molecular mechanisms underlying the reduction in Cd accumulation in hot pepper (Capsicum annuum) by B application. A hydroponic experiment was conducted to compare the subcellular distribution of Cd, transcriptome profile, degree of pectin methylation, and glutathione (GSH) synthesis in the roots of hot pepper under different B and Cd conditions. Boron supply promoted root cell wall biosynthesis and pectin demethylation by upregulating related genes and increasing cell wall Cd concentration by 28%. In addition, with the application of B, the proportion of Cd in root cell walls increased from 27% to 37%. Boron supplementation upregulated sulfur metabolism-related genes but decreased cysteine and GSH contents in the roots. As a result, shoot Cd concentration decreased by 27% due to the decrease in GSH, a critical long-distance transport carrier of Cd. Consequently, B supply could reduce the uptake, translocation, and accumulation of Cd in hot pepper by retaining Cd in the root cell walls and decreasing GSH content.

Increasing media pH contribute to the absorption of boron via roots to promote the growth of citrus

Low pH is an important limiting factor for plant development in the south of China due to problems of acid red soil and boron (B) deficiency. Whereas, there is very limited information on the relationship between media pH and B distribution in plant, the physiological process changed by the interaction of pH and B in citrus growth also unclear. This experiment was conducted on trifoliate rootstock by employing two different concentrations of B (0 or 10 μM B) under three pH levels: pH 4, pH 5, and pH 6. Our results illustrate that low pH inhibite plant growth and cause oxidative stress in the roots, resulting in cell membrane injury. The increase of pH and B addition reduce the accumulation of ROS (O2.- and H2O2) by regulating the activity of Class Ⅲ peroxidases (CIII Prxs). Moreover, increased pH improves the internal circulation of B in plants and decrease the content of lignin and cellulose in cell wall (CW). In summary, our investigation demonstrated that the increase of pH in nutrient solution can accelerate the re-distribution of B by roots to promote citrus growth. The accumulation of B in roots can protect plants from the damage of ROS by regulating the activity of CIII Prxs as well as decrease the content of lignin and cellulose are to promotes roots elongation.

Defects in meristem maintenance, cell division, and cytokinin signaling are early responses in the boron deficient maize mutant tassel-less1.

Meristems house the stem cells needed for the developmental plasticity observed in adverse environmental conditions and are crucial for determining plant architecture. Meristem development is particularly sensitive to deficiencies of the micronutrient boron, yet how boron integrates into meristem development pathways is unknown. We addressed this question using the boron-deficient maize mutant, tassel-less1 (tls1). Reduced boron uptake in tls1 leads to a progressive impairment of meristem development that manifests in vegetative and reproductive defects. We show, that the tls1 tassel phenotype (male reproductive structure) was partially suppressed by mutations in the CLAVATA1 (CLV1)-ortholog, thick tassel dwarf1 (td1), but not by other mutants in the well characterized CLV-WUSCHEL pathway, which controls meristem size. The suppression of tls1 by td1 correlates with altered signaling of the phytohormone cytokinin. In contrast, mutations in the meristem maintenance gene knotted1 (kn1) enhanced both vegetative and reproductive defects in tls1. In addition, reduced transcript levels of kn1 and cell cycle genes are early defects in tls1 tassel meristems. Our results show that specific meristem maintenance and hormone pathways are affected in tls1, and suggest that reduced boron levels induced by tls1 are the underlying cause of the observed defects. We, therefore, provide new insights into the molecular mechanisms affected by boron deficiency in maize, leading to a better understanding of how genetic and environmental factors integrate during shoot meristem development.

Boron fertilization of root chicory (Cichorium intybus var. sativum) in a field experiment in Kwazulu-Natal, South Africa

Root chicory (Cichorium intybus var. sativum ) production is increasing in KwaZulu-Natal Province, South Africa, especially on coarse-textured soils, prone to boron (B) deficiency. Literature on the response of chicory to B application is scarce and largely anecdotal. A field experiment was conducted to determine this response and the movement of B in the upper 60 cm of a loamy sand. Eight rates of B (from 0 to 3.5 kg ha−1) were either soil- or foliar-applied, with four replications. Soil samples were taken pretrial and after each of the two harvests at 15 cm depth intervals to 60 cm for fertility analysis. Hot water soluble B was also analyzed. Results are presented as means of the two harvest periods for yield, and leaf and soil analysis. Root analysis is reported for the second harvest only. Yield effects were not significant (p > 0.05) for both seasons over all B application rates. Application method (App), and the App × B interaction were also not significant. Root chicory was tolerant to 3.5 kg B ha−1. Multiple rooting, especially in the control plots, was significant compared to plots that received B and root rot incidence was also significantly higher, probably due to B deficiency. Root quality was compromised at about 0.1 mg B kg−1 in the topsoil. A highly significant movement of B occurred from the topsoil to 45–60 cm measured after the final harvest. The application rate, App, and time were all significant for the averaged data from the 0–15 to 45–60 cm depths.

MicroRNA Mediated Plant Responses to Nutrient Stress.

To complete their life cycles, plants require several minerals that are found in soil. Plant growth and development can be affected by nutrient shortages or high nutrient availability. Several adaptations and evolutionary changes have enabled plants to cope with inappropriate growth conditions and low or high nutrient levels. MicroRNAs (miRNAs) have been recognized for transcript cleavage and translational reduction, and can be used for post-transcriptional regulation. Aside from regulating plant growth and development, miRNAs play a crucial role in regulating plant’s adaptations to adverse environmental conditions. Additionally, miRNAs are involved in plants’ sensory functions, nutrient uptake, long-distance root transport, and physiological functions related to nutrients. It may be possible to develop crops that can be cultivated in soils that are either deficient in nutrients or have extreme nutrient supplies by understanding how plant miRNAs are associated with nutrient stress. In this review, an overview is presented regarding recent advances in the understanding of plants’ responses to nitrogen, phosphorus, potassium, sulfur, copper, iron, boron, magnesium, manganese, zinc, and calcium deficiencies via miRNA regulation. We conclude with future research directions emphasizing the modification of crops for improving future food security.

PH-Dependent mitigation of aluminum toxicity in pea (Pisum sativum) roots by boron

Boron (B) deficiency and aluminum (Al) toxicity are two major constraints on plants grown in acidic soils. B supply mitigates Al toxicity; however, the underlying mechanisms of this process remain elusive. In this work, Pisum sativum plants were used to address this issue. In the absence of pH buffers, B supply had a better mitigation effect on Al-induced root inhibition at pH 4.0 than pH 4.8. However, in MES buffered solution, mitigating effects of B on Al-induced root inhibition were more pronounced at pH 4.8, indicating a strong pH dependency of this process. Quantification of pH-dependent accumulation of Al in various root zones, modification of root pH by an exogenous addition of rapid alkalization factor (RALF), and measuring changes in the rhizosphere pH by fluorescent dyes have revealed operation of two concurrent mechanisms to explain alleviation of the inhibition of root elongation induced by Al toxicity by boron: (1) via enhancing rhizosphere pH under strong acidic stress (pH4.0), and (2) via stabilizing of cell wall by cross-linking with RGII at relatively higher pH (4.8). These findings provide scientific basis and support for the application of B fertilizers in the regions with inherited soil acidity.

Boron deficiency affects ATP hydrolysis of plasma membrane and nutrients uptake in coffee: Consequences for plant growth

Boron (B) shapes the plasma membrane structure and modulates the plasma membrane H+-ATPase activity stimulating nutrients uptake by the plant root system. However, the influence of B-nutritional status on plasma membrane H+-ATPase activity of some plants remains unclear, especially in dicots with higher B requirement, such as coffee. This study investigated the effects of B-nutritional status on ATP hydrolysis of plasma membrane and nutrients uptake in coffee. Coffee seedlings were grown in substrate with six B levels (0.1, 0.2, 0.4, 0.6, 0.8 and 1.0 mg dm−3, as H3BO3) for 153 days and plasma membrane H+-ATPase activity was evaluated in the roots, as well as nutrient concentration and accumulation in leaf tissues and plant growth. The B nutritional status greatly influenced plasma membrane H+-ATPase activity in roots. At 1.0 mg dm−3, the ATPase hydrolysis activity was six times greater and H+ transport two times higher compared to the lowest level of 0.1 mg dm−3. The B supply increased significantly leaf concentrations of B, K, P, Mg, and Ca; nevertheless, accumulation of these nutrients did not vary in the leaves because leaf biomass decreased at high B levels.

HYDROXY ACIDS AND POLYOLS AS POTENTIAL EXTRACTANTS FOR IONMETRIC DETERMINATION OF BORON IN SOILS

Boron is an essential element for plants, animals, and humans. Its deficiency in plants may result in reduced growth rates, yield loss, and even death. At the same time, excess of boron is toxic for both plants and living organisms. Boron is important for steroid hormones production, vitamin D and minerals metabolism, formation of bone tissue, and affects estrogen and testosterone levels. The primary source of boron for humans and other living organisms is plant-origin food. The richest ones are fruits and nuts. High concentrations of boron are found in raisins (22 mg/kg), peanuts (17 mg/kg), peanut butter (14,5 mg/kg). In the agriculture the boron monitoring in soils and water irrigation is particularly important because this element is crucial for plant growth Boron deficiency has a drastic effect on fruit quality and yield, even when there are only mild or moderate foliar symptoms.
 The main source of boron for plants is soil and water. Quantitative determination of boron in soil extracts can be performed using spectrophotometric, potentiometric, chromatographic, atomic absorption spectrophotometric, and inductively coupled plasma techniques. The most popular are inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). These methods are described in the appropriate standards PN-EN ISO 11885:2009 and PN-EN ISO 17294–1:2007.
 Boric acid is known to form complexes through esterification reactions with hydroxy-group in molecules of amino- and carboxylic acids, carbohydrates, nucleotides and vitamins that can be used for boron extraction from soils. Partial esterification results in monoesters (1:1 complex) and complete esterification leads to the bicyclic diester (1:2 complex).
 In present research the tetrafluoroborate selective sensor applicable for fluoroborate formation reaction monitoring was used as an analytical tool for the investigation of an impact of soil extraction procedure for boron analysis. The investigation of alternative soil boron extraction procedures using α-hydroxy acids (and other cis-diol containing compounds) and subsequent quantitative analysis of boron by kinetic-potentiometric monitoring of fluoroborate formation rate with use of previously developed [BF4]¯-selective electrode have been performed. The kinetics of complex destruction under fluoride containing acidified media by means of kinetic-potentiometric analysis has been investigated. The possible boron losses during its extraction from soils have been checked.

Nanoencapsulated Boron Foliar Supply Increased Expression of NIPs Aquaporins and BOR Transporters of In Vitro Ipomoea batatas Plants

Nanoencapsulation with proteoliposomes from natural membranes has been proposed as a carrier for the highly efficient delivery of mineral nutrients into plant tissues. Since Boron deficiency occurred frequently in crops, and is an element with low movement in tissues, in this work, nanoencapsulated B vs free B was applied to in vitro sweet potato plants to investigate the regulation of B transporters (aquaporins and specific transporters). Additionally, an metabolomic analysis was performed, and mineral nutrient and pigment concentrations were determined. The results showed high increases in B concentration in leaves when B was applied as encapsulated, but also Fe and Mn concentration increased. Likewise, the metabolomics study showed that single carbohydrates of these plants could be related to the energy need for increasing the expression of most NIP aquaporins (NIP1;2, NIP1;3; NIP4;1, NIP4;2, NIP5;1, NIP6;1, and NIP7) and boron transporters (BOR2, BOR4 and BOR7;1). Therefore, the results were associated with the higher mobility of encapsulated B into leaves and the stimulation of transport into cells, since after applying encapsulated B, the aforementioned NIPs and BORs increased in expression.

Improving boron use efficiency via different application techniques for optimum production of good quality potato (Solanum tuberosum L.) in alkaline soil.

Boron (B) deficiency is a widespread problem in alkaline soils which affects yield and quality of potato but is often ignored by the growers. That’s why, we compared the impact of different methods of boron application (foliar spray, fertigation and soil dressing) along with control on boron use efficiency (BUE), quality and yield of potato in alkaline soils. Boron (0.5 kg ha-1) applied as a foliar spray had significantly increased plant height, tuber per plant, tuber volume and enhanced the quality in terms of vitamin C, starch and B content of potato compared to other methods. Moreover, foliar applied B significantly improved B uptake and it use efficiency over other application methods. B concentration in tubers were strongly correlated with vitamin C and starch contents. The application methods were ranked as foliar spray>fertigation>soil dressing in term of their effectiveness towards potato yield and quality improvement. Thus, for optimum production of good quality potato, B should be applied as foliar spray at the rate of 0.5 kg B ha-1 in existing agro-climatic conditions.

The Xyloglucan Endotransglucosylase/Hydrolase Gene XTH22/TCH4 Regulates Plant Growth by Disrupting the Cell Wall Homeostasis in Arabidopsis under Boron Deficiency.

TCH4 is a xyloglucan endotransglucosylase/hydrolase (XTH) family member. Extensive studies have shown that XTHs are very important in cell wall homeostasis for plant growth and development. Boron (B), as an essential micronutrient for plants, plays an essential role in the cross-linking of cell wall pectin. However, the effect of B on cell wall organization is unclear. This study aimed to explore the mechanism of plant adaption to B stress by investigating the role of TCH4 in cell wall homeostasis. We conducted both plate and hydroponic cultures of wild-type Col-0 and overexpression and gene knockout lines of XTH22/TCH4 to analyze the phenotype, components, and characteristics of the cell wall using immunofluorescence, atomic force microscopy (AFM), and transmission electron microscopy (TEM). B deficiency induces the expression of TCH4. The overexpression lines of TCH4 presented more sensitivity to B deficiency than the wild-type Col-0, while the knockout lines of TCH4 were more resistant to low B stress. Up-regulation of TCH4 influenced the ratio of chelator-soluble pectin to alkali-soluble pectin and decreased the degree of methylesterification of pectin under B-deficient conditions. Moreover, we found that B deficiency disturbed the arrangement of cellulose, enlarged the gap between cellulose microfibrils, and decreased the mechanical strength of the cell wall, leading to the formation of a thickened and deformed triangular region of the cell wall. These symptoms were more profound in the TCH4 overexpression lines. Consistently, compared with Col-0, the O2− and MDA contents in the TCH4 overexpression lines increased under B-deficient conditions. This study identified the B-deficiency-induced TCH4 gene, which regulates cell wall homeostasis to influence plant growth under B-deficient conditions.

The effect of 24-epibrassinolide on gene expression related to cell walls under boron deficiency and toxicity in the leaves of Arabidopsis thaliana

The changing composition of plant cell walls allows for the continuation of the existing structure under normal conditions and also the protection of physical integrity under altering environmental conditions. In this study, the possible effects of the 24-Epibrassinolide (EBL) hormone under boron (B) deficiency and toxicity conditions on the expression of cell wall-related genes [cellulose synthase (CESA), expansin (EXP), xyloglucan endotransglucosylase/hydrolase (XTH) and pectin methylesterase (PME)] were investigated in the rosette leaves of Arabidopsis thaliana. For this purpose, 0 or 3000 ?M of boric acid (BA) and/or 1 ?M of EBL were applied to the plants which were grown in a hydroponic medium for five and ten weeks. While B-toxicity elevated the mRNA levels of the CESA4 and CESA8 genes in the leaves of the five-week-old plants, B-stress (B-deficiency and -toxicity) caused an increase in the expression of the CESA4, CESA6, and CESA8 genes in the ten-week-old plants. The transcript levels of the EXPA5 gene increased under B-stress in the ten-week-old plants whereas the expression of the EXPA8 gene decreased when compared to the control at two developmental stages. Co-treatment of EBL and B-stress strongly elevated the transcript level of the EXPA5 gene in the ten-week-old plants and the EXPA8 gene at both developmental stages. The EXPA14 and XTH23 genes exhibited distinct expression profiles under B-deficiency and -toxicity in both the five- and ten-week-old plants. The transcript level of the XTH21 gene was upregulated in the leaves of the plants exposed to B-stress. The mRNA level of the PME2 and PME41 genes was generally upregulated in response to B-stress in both the five- and ten-week-old plants. 24-Epibrassinolide alone and in combination with B-stress led to a remarkable increase in the expression of the XTH and PME genes compared to the control. These results demonstrate that cell wall genes generally show a similar pattern of expression at both developmental stages and the EBL hormone induces changes in the expression levels of cell wall-related genes under B-stress.

THE AVAILABILITY STATUS OF BORON IN THE CULTIVATED SOIL OF NEPAL

Boron is available in nature in rocks and deposits and the availability is influenced by soil organic matter, soil pH, soil texture, and temperature and is taken up by plants in non-ionic form H3BO3 (boric acid) but this concentration account for only about 10% of total soil boron leading to boron deficiency. Also, boron toxicity may occur in low rainfall, extremely alkaline, and saline soils harming plants’ growth and development. Boron shortage and toxicity in plants have a fairly narrow range, and both are detrimental. Hence, it is needed to critically balance boron homeostasis in cropping soil. The concentration of boron in cultivated soil in different agroecological regions was found to be low to very low (1mg/kg of soil) in this review study, which was undertaken to familiarize the status of boron in Nepalese cultivated land. In separate micronutrient investigations, a few additional micronutrients were shown to be medium albeit, boron was found to be low even in the valley (>0.01ppm) including all three ecological regions. This shows boron deficiency is a universal problem in Nepal affecting 80-90% of agricultural soil. And this problem can be corrected by both foliar applications and by soil application of boron sources such as borate as per the recommended dose.

Jasmonate Signaling and Remodelling of Cell Wall Metabolism Induced by Boron Deficiency in Pea Shoots

Jasmonate Signaling and Remodelling of Cell Wall Metabolism Induced by Boron Deficiency in Pea Shoots

Bringing out the potential of organoboron compounds by designing the chemical bonds and spaces around boron.

Since the structures, reactivity and properties of organoboron compounds stem from the electron deficiency and low electronegativity of boron, the design of the chemical bonds attached to boron as well as the space provided by substituents around boron leads to particular reactivity and functions of organoboron compounds. Based on the concept of vacant boron p-orbital engineering in combination with peripheral space design for boron, we have developed new organoboron compounds, which exhibit exotic reactivity and properties and boron-mediated organic transformations capable of constructing large π-conjugated systems. Here we describe our recent study by focusing on three topics: (i) the synthesis and its derivatization, small-molecule activation and application to materials science of a two-coordinate boron cation (borinium ion), (ii) a 9-borafluorene-mediated benzannulation reaction of alkyne derivatives and (iii) BN-substituted molecules featuring a 4nπ heterocycle exhibiting unique electronic and emission properties. The molecules and reactions appearing in this article are unprecedented, yet feature very simple systems, and therefore clearly demonstrate intrinsic and new potential of organoboron compounds.