Leaflet Boron Concentration Reduced with Hybrid Pistacia vera Rootstocks

Excessive boron (B) in soil and water is a problem for pistachio (Pistacia vera L.) production in the San Joaquin Valley (SJV) of California. Although amenable, leaching of B requires more water than chlorine (Cl) or sodium (Na) and is increasingly difficult as B in irrigation water increases. The lack of subsurface drainage to the ocean increases soil salinity in many growing areas, especially on the west side of the SJV where B is often excessive natively in the soil and water. Pistachio rootstocks that can tolerate or exclude B may be a partial solution. For the past decade in California, the dominant rootstock has been seedlings and clonal selections of University of California Berkeley 1 (UCB-1), which is a hybrid of P. atlantica × P. integerrima. This reliance on a genetically similar pool of rootstocks has constrained Pistacia’s genetic potential for adapting to high-salt environments. This study compared scion and rootstock leaflet B concentration of novel hybrid experimental rootstocks with variable percentages of P. vera and P. integerrima heritage with UCB-1. Rootstocks with P. vera heritage limited B in both rootstock and scion leaflets compared with UCB-1. In six trials conducted over several years, leaflet B in ungrafted hybrid rootstocks having 62.5% to 75% P. vera and 25% to 37.5% P. integerrima heritage had 27.6% to 43.1% lower B leaflet concentration than did UCB-1. Depending on the experiment and year, grafted rootstocks having 37.5% P. vera and 62.5% P. integerrima heritage had 46.8% to 70.8% lower B scion leaflet concentration than did UCB-1. Genetic variation in B uptake in Pistacia species and interspecific hybrids, and among individual seedlings within populations, allows the breeding of pistachio rootstocks more tolerant of excess B.

Assessment of Agroeconomic Indicators of Sesamum indicum L. as Influenced by Application of Boron at Different Levels and Plant Growth Stages

To achieve the nutritional target of human food, boron (B) has been described as an essential mineral in determining seed and theoretical oil yield of Sesamum indicum L. The research to increase its cultivation is garnering attention due to its high oil content, quality and its utilization for various purposes, which include human nutrition as well as its use in the food industry. For this, a two-year field experiment was performed at PAU, Punjab, India to determine the effect of different concentrations of foliar-applied B (20, 30 and 40 mg L−1) and different growth stages of crop, i.e., we measured the effects on agroeconomic indicators and certain quality parameters of sesame using different concentrations of B applied at the flowering and capsule formation stages as compared to using water spray and untreated plants. Water spray did not significantly affect the studied parameters. However, B application significantly increased the yield, uptake, antioxidant activity (AOA) and theoretical oil content (TOC) compared to those of untreated plants. The maximum increase in seed yield (26.75%), B seed and stover uptake (64.08% and 69.25%, respectively) as well as highest AOA (69.41%) and benefit to cost ratio (B:C ratio 2.63) was recorded when B was applied at 30 mg L−1 at the flowering and capsule formation stages. However, the maximum sesame yield and B uptake were recorded when B was applied at a rate of 30 mg L−1. A significant increase in TOC was also recorded with a B application rate of 30 mg L−1. For efficiency indices, the higher values of boron agronomic efficiency (BAE) and boron crop recovery efficiency (BCRE) were recorded when B was applied at 20 mg L−1 (5.25 and 30.56, respectively) and 30 mg L−1 (4.96 and 26.11, respectively) at the flowering and capsule formation stages. In conclusion, application of B @ 30 mg L−1 at the flowering and capsule formation stages seemed a viable technique to enhance yield, B uptake and economic returns of sesame.

Transient elastography in patients at risk of liver fibrosis in primary care: a follow-up study over 54 months

BackgroundLiver fibrosis assessment services using transient elastography are growing in primary care. These services identify patients requiring specialist referral for liver fibrosis, and provide an opportunity for recommending lifestyle change. However, there are uncertainties regarding service design, effectiveness of advice given, and frequency of follow-up.AimsTo assess: a) effectiveness of standard care lifestyle advice for weight management and alcohol consumption; b) uptake for liver rescan; c) usefulness of a 4.5-year time interval of rescanning in monitoring progression of liver fibrosis.Design & settingAnalysis of patient outcomes 4.5 years after first ‘liver service’ attendance that included transient elastography in five GP practices in Southampton, UK.MethodOutcomes included weight, alcohol consumption, rescan uptake, time interval between scans and change in liver fibrosis stage.Results401 participants were re-contacted. Mean ± SD wt loss was 1.2 kg ±8.4 kg (P=0.005), alcohol AUDIT grade increased by 7.8% (P=<0.001). 116/401 participants were eligible for liver rescanning. 59/116 (50.9%) agreed to undergo rescanning. Mean ± SD time interval between scans was 53.6±3.4 months. Liver fibrosis progressed from mild (≥6.0 kPa-8.1kPa) to significant fibrosis (8.2 kPa-9.6kPa) in 3.4% of patients; from mild to advanced fibrosis (9.7 kPa-13.5kPa)/cirrhosis (≥13.6 kPa) in 15.3% of patients, and did not progress in 81.3%. No baseline factors were independently associated with liver fibrosis progression at follow-up.ConclusionRescan recall attendance and adherence to lifestyle changes needs improving. Optimum time interval between scans remains uncertain. After a mean interval of 53.6 months between scans, and with no specific predictors indicated, a substantial minority (18.7%) experienced a deterioration in fibrosis grade.

Improved Method of Boron Fertilization in Rice (Oryza sativa L.)–Mustard (Brassica juncea L.) Cropping System in Upland Calcareous Soils

Calcareous soils are highly deficient in boron (B) due to having high levels of free CaCO3 and low organic matter. This has become one of the most important deficient micronutrients in Indian soil after zinc (Zn). For various rice (Oryza sativa L.)-based cropping systems, B fertilization is essential for increasing crop productivity and the biofortification of the crop, thus a suitable soil application protocol for B fertilization is required for B-deficient soils. In a six-year experiment, different rates of B application, namely, 0.5, 1.0, 1.5, and 2.0 kg ha−1 y−1, were evaluated to determine the effects of three different modes of B fertilization, i.e., applied only in the first year, applied in alternating years, and applied every year, in a rice (Oryza sativa L.)–Indian mustard (Brassica juncea L.) cropping system. It was observed that the application of B at 1.5 kg ha−1 every year or 2 kg ha−1 in alternate years resulted in the highest yield of rice and mustard, as well as the maximum system productivity of the rice–mustard cropping system. Application of 2 kg ha−1 of B in the initial year showed the maximum B uptake by rice, while application of 1.5–2.0 kg ha−1 of B every year resulted in the maximum B uptake by the mustard crop. Application of B at 2 kg ha−1 in alternate years or 1.5 kg ha−1 every year was the best B-application protocol in B-deficient calcareous soils for ensuring the highest productivity of the rice–mustard cropping system and B availability in the soil.

Vascular Tissue-Specific Expression of Bnac4.BOR1;1c, an Efflux Boron Transporter Gene, is Regulated in Response to Boron Availability for Efficient Boron Acquisition in Brassica Napus

AimsBnaC4.BOR1;1c is required for B acquisition in Brassica napus (B. napus) under low B stress. This study aimed to reveal the B regulatory mechanism of BnaC4.BOR1;1c and its physiological roles in B translocation from roots to shoots and B distribution in shoots. MethodsTransgenic Arabidopsis plants expressing GUS (β-glucuronidase) under different promoters were generated and the mRNA, and GUS activity was quantitatively measured. The in-situ PCR and immunohistochemistry in B. napus were performed to investigate BnaC4.BOR1;1c expression pattern and localization. Furthermore, assays of B transport and distribution in wild type B. napus and BnaC4.BOR1;1c RNAi lines were carried out to elucidate its physiological roles. ResultsResults showed that BnaC4.BOR1;1c mRNA abundance is negatively correlated with B availability, which was mediated by the 29 nt sequence in the 5’ terminal region of 5’-UTR. Besides, the 5’-UTR simultaneously regulates protein expression level, most probably depending on the translation efficiency. BnaC4.BOR1;1c mainly localizes on the plasma membrane of vascular bundle cells in roots and shoots with a polar localization manner that is probably beneficial to B xylem loading in roots and B unloading from xylem to phloem in vascular bundle of shoots. Short-term 10B uptake analysis demonstrates that BnaC4.BOR1;1c preferentially distributes B to developing leaves and flowers under B deficiency. ConclusionThis study reveals combined regulatory action of mRNA abundance and translation efficiency mediated by the 5’-UTR in BnaC4.BOR1;1c in response to B availability and its physiological role in preferential B acquisition in developing tissues of B. napus.

Can the new boron-fertilization method improve the system productivity of rice (Oryza sativa L.) – mustard (Brassica juncea L.) cropping system under upland calcareous soils?

Background Calcareous soils are highly deficient in boron (B) which has become one of the most important deficient micronutrients in Indian soil after zinc (Zn). For various rice-based cropping systems, B-fertilization is essential for increasing crop productivity and the biofortification of the crop, thus suitable soil application protocol for B-fertilization are required for B-deficient soils. Results In a six years-long experiment, different rates of B application viz. 0.5, 1.0, 1.5, and 2.0 kg ha− 1 y− 1 were evaluated to determine the effects of three different modes of B fertilization viz. applied only in the first year, in alternating years, and every year in rice ( Oryza sativa L.) – Indian mustard (Brassica juncea L.) cropping system. It was observed that the application of B at 1.5 kg ha− 1 in every year or 2 kg ha− 1 in alternate years resulted in the highest yield of rice and mustard as well as the system productivity of the rice–mustard cropping system. Application of 2 kg ha− 1 B in the initial year showed the maximum B-uptake by rice, while, application of 1.5–2.0 kg ha− 1 B in every year resulted in the maximum B-uptake by the mustard crop. Conclusion Application of B at 2 kg ha− 1 in alternate years or 1.5 kg ha− 1 in every year was the best B-application protocol under rice–mustard cropping system in B-deficient calcareous soils for ensuring the best system productivity of rice–mustard cropping system and B-availability in soil.

Field evaluation of a boron recycling fertiliser

Boron (B) is a plant nutrient and a limited mineral resource. Therefore, secondary B sources such as end-of-life cellulose fiber insulation (CFI) should be preferred for B fertiliser production over primary borates. In addition, crop B fertilisation is challenging because B is only weakly adsorbed in soils and prone to leaching in particular if the soil pH is below 7. The objectives of this study were to assess the effect of pyrolysed CFI (B-Biochar) on crop B uptake in the field and on B leaching in a lysimeter study. B-Biochar was pyrolysed at 600 °C and tested (1) in a field experiment with maize (Zea mays L.) and sunflower (Helianthus annuus L.), and (2) in a lab microlysimeter experiment to study B leaching under simulated rainfall. In the field experiment, B concentration in plant tissue increased by up to 100% with B-Biochar compared to the control (from 29.6 to 61.6 mg B/kg in young sunflower leaves) and was only slightly lower (–10% to –20%) than with water-soluble Na-tetraborate (Borax). This lower uptake was attributed to the slow-release properties of the B-Biochar. In the lysimeter experiment, 41% and 55% of added B through B-Biochar was leached below 16 cm depth when fertilised with 1 and 2 kg B/ha, respectively, but B concentration of the leachate remained below the 1 mg B/L threshold value for drinking water in the European Union. In conclusion, CFI has a strong potential as a secondary B source for fertiliser production, and pyrolysis appears to be a suitable process for that purpose. During the processing of CFI to fertiliser, more focus should be given to slow B release in the future in order to reduce losses by leaching.

Influence of lime, phosphorus and boron on performance of maize (Zea mays L.)in acidic soil of Nagaland

A pot experiment was conducted in an acidic sandy clay loam soil during the kharif season of 2016 and 2017 to study the performance of maize using two lime levels (0 and ¼ lime of LR), four phosphorus levels (0, 13.4, 26.8 and 40.2 mg P2O5 kg-1) and three boron levels (0, 0.45 and 0.90 mg B kg-1) with maize as test crop. The experiment was designed in complete randomized design with three replications. Results revealed that plant height, number of leaves and leaf area index increased appreciably with the advancement of age of the crop and maximum values were recorded at harvest. Application of ¼ lime of LR increased plant height at harvest, grain and stover yield to the extent of 13.1, 24.6 and 23.0%, respectively over control. Phosphorus and boron uptake increased significantly with lime application and enhanced by 45.9, 27.0% in grain and 44.5 and 29.3% in stover, respectively over control. Application of phosphorus significantly enhanced the growth attributes, yield attributes, grain and stover yield and P and B uptake except rows per cob and test weight and the highest values of these parameters were recorded with 40.2 mg P2O5 kg-1. However, grain and stover yield and P and B uptake in grain and stover remained statistically at par with 26.8 mg P2O5 kg-1application.Application of 26.8 mg P2O5 kg-1 enhanced plant height at harvest, grain and stover yield by 21.2, 23.2 and 19.8%, respectively over control. Plant height, leaves plant-1, cob length, cob girth, grains row-1, grains cob-1, grain and stover yield and P and B uptake were influenced significantly with boron application and maximum values were recorded with 0.90 mg B kg-1. At harvest plant height, grain and stover yield was increased by 4.9, 10.9 and 10.6%, respectively with application of 0.90 mg B kg-1 over control. Lime application significantly increased the available P and B status of post harvest soil. Application of P and B significantly improved their respective status in post harvest soil.Thus, results suggested that application of ¼ lime of LR along with 26.8 mg kg-1 P2O5 and 0.90 mg kg-1 boron proved beneficial for cultivation of maize in acidic soil condition of Nagaland.

Boron: More Than an Essential Element for Land Plants?

Although boron (B) is an element that has long been assumed to be an essential plant micronutrient, this assumption has been recently questioned. Cumulative evidence has demonstrated that the players associated with B uptake and translocation by plant roots include a sophisticated set of proteins used to cope with B levels in the soil solution. Here, we summarize compelling evidence supporting the essential role of B in mediating plant developmental programs. Overall, most plant species studied to date have exhibited specific B transporters with tight genetic coordination in response to B levels in the soil. These transporters can uptake B from the soil, which is a highly uncommon occurrence for toxic elements. Moreover, the current tools available to determine B levels cannot precisely determine B translocation dynamics. We posit that B plays a key role in plant metabolic activities. Its importance in the regulation of development of the root and shoot meristem is associated with plant developmental phase transitions, which are crucial processes in the completion of their life cycle. We provide further evidence that plants need to acquire sufficient amounts of B while protecting themselves from its toxic effects. Thus, the development of in vitro and in vivo approaches is required to accurately determine B levels, and subsequently, to define unambiguously the function of B in terrestrial plants.