المؤلفون: Khosro Ershadimanesh, Adel Siosemardeh, Farzad Hoseeinpanahi

المصدر: Frontiers in Agronomy, Vol 6 (2024)

مصطلحات موضوعية: chlorophyll, grain yield, photosynthetic materials, remobilization, source and sink limitation, water soluble carbohydrates, Agriculture, Plant culture, SB1-1110

الوصف: The source–sink (S-S) ratio during the grain-filling period is crucial for wheat crop yield. The aim of this study was to investigate the relative sensitivity of grain yield in response to treatments of S-S ratio changes to determine the extent of S-S limitation during grain filling in modern wheat genotypes. The S-S manipulation treatments included four levels: check (CH), removal of flag leaf (RFL), removal of all leaves (RAL), and removal of the upper half of the spikes (RHS). The results showed significant differences between genotypes (pb< 0.001%) in all traits. Drought stress decreased grain weight per spike (GWS) (g) and grain yield (GY) (kg/ha) by 18% and 25%, respectively. The average reduction in GWS under irrigation and rainfed conditions was 8.25% and 6.71% for RFL and 12.25% and 11.15% for RAL, respectively. By RFL and RAL, increasing the remobilization from the stem and spike straw helped to reduce the effects of source limitation. Also, by RHS, the reduction in photosynthetic materials production in both conditions was only equivalent to 38% and 29% of the expected values, respectively, which shows the presence of strong sinks in vegetative organs (stem and spike) compared to grains. Vegetative organs seem to have a larger sink for the uptake of photosynthetic materials than grains when the source–sink ratio increases. However, high-yield genotypes showed more severe source limitation, while low-yield genotypes showed more relative sink limitation. Overall, to increase the yield potential in high-yielding genotypes, photosynthetic sources and sinks in low-yielding genotypes should be improved.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fagro.2024.1393267/fullTest; https://doaj.org/toc/2673-3218Test

الوصول الحر: https://doaj.org/article/5eceb17887f2493cbb421e94c35fa41bTest

المؤلفون: C. D. Rosendahl, Y. Roebbert, A. Schippers, S. Weyer

المصدر: Frontiers in Microbiology, Vol 14 (2023)

مصطلحات موضوعية: uranium, isotope fractionation, remobilization, laboratory batch experiments, Thiobacillus denitrificans, Acidithiobacillus ferrooxidans, Microbiology, QR1-502

الوصف: Uranium (U) contamination of the environment causes high risk to health, demanding for effective and sustainable remediation. Bioremediation via microbial reduction of soluble U(VI) is generating high fractions (>50%) of insoluble non-crystalline U(IV) which, however, might be remobilized by sulfur-oxidizing bacteria. In this study, the efficacy of Acidithiobacillus (At.) ferrooxidans and Thiobacillus (T.) denitrificans to mobilize non-crystalline U(IV) and associated U isotope fractionation were investigated. At. ferrooxidans mobilized between 74 and 91% U after 1 week, and U mobilization was observed for both, living and inactive cells. Contrary to previous observations, no mobilization by T. denitrificans could be observed. Uranium mobilization by At. ferrooxidans did not cause U isotope fractionation suggesting that U isotope ratio determination is unsuitable as a direct proxy for bacterial U remobilization. The similar mobilization capability of active and inactive At. ferrooxidans cells suggests that the mobilization is based on the reaction with the cell biomass. This study raises doubts about the long-term sustainability of in-situ bioremediation measures at U-contaminated sites, especially with regard to non-crystalline U(IV) being the main component of U bioremediation.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmicb.2023.1190962/fullTest; https://doaj.org/toc/1664-302XTest

الوصول الحر: https://doaj.org/article/ea041c42e4a3428297bbf0417e75c1b9Test

المؤلفون: Yan Sun, Yang Han, Zikai Xu, Jinting Zhang, Jianbo Shen, Lingyun Cheng

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: post-silking phosphorus uptake, phosphorus remobilization, grain formation, grain phosphorus, human nutrition and health, Plant culture, SB1-1110

الوصف: IntroductionLower phosphorus (P) availability limits crop productivity in agroecosystems. The remobilization of P from the source to the sink organs plays an important role in enhancing the P-utilization efficiency of crops. During the grain filling stage, phosphorus flow to the developing grains, the primary sink, determines crop yield. However, the specific contributions of different organs to grain P throughout the post-silking period in maize remain unclear.MethodsIn our study, three maize inbred lines (CIMBL89, Ji846, and CML118) with contrasting P statuses were selected and grown in a field with high P (HP, 150 kg ha–1 P2O5) and low P (LP, 0 kg ha–1 P2O5) conditions.ResultsThe grain yield of CIMBL89 was 69% and 169% greater under HP supply, and 83% and 309% greater than those of Ji846 and CML118 under LP supply, respectively. The ear length, ear diameter, and kernel row number of CML118 were lower than those of CIMBL89 and Ji846 under HP conditions. Most of the P (87%) in the grains of CIMBL89 came from P uptake at the LP supply, while almost all P (95%) came from P remobilization in various organs at the HP supply after silking. In contrast, 91% of the P found in the grain of CML118 came from P remobilization under LP supply, while 76% came from P uptake under HP supply after silking.DiscussionIn conclusion, our findings suggest that CIMBL89, with greater P acquisition efficiency, contributes to grain formation and production during the post-silking period under LP conditions. Additionally, CIMBL89 can fully remobilize P and avoid the extravagant absorption of P in P-sufficient soil, which sets it apart from Ji846 and CML118.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1223532/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/ab26a4cd1080474288e12625e264b4d4Test

المؤلفون: Michael Schwarz, Lediane Marcon, Andreas Lorke

المصدر: Frontiers in Earth Science, Vol 11 (2023)

مصطلحات موضوعية: bubble size spectra, reservoir monitoring, heavy metal transport, sediment remobilization, freshwater bubbles, Science

الوصف: The widespread release of gas bubbles from aquatic sediments (ebullition) has been receiving growing scientific interest because of its globally relevant contribution to methane emissions. Besides being an efficient transport pathway for methane and other gases to the atmosphere, these bubbles have the potential to mobilize resources and pollutants previously buried in the sediment by carrying solutes and particles on their surface. The phenomenon of bubbles transporting substances other than gases is well studied in open water and widely used in technical applications, such as froth flotation or dissolved air floatation. Research on the transport capabilities of natural bubbles forming in, and being released from, aquatic sediments is exceedingly rare. Ebullition resulting from biogenic gas production in sediments is characterized by large spatial and temporal variability and bubble sizes exceed those typically used in technical applications. Here we summarize the current state of research concerning bubble mediated transport (BMT) from aquatic sediments and develop a perspective based on these findings and own experimental results. We present measurements from a shallow reservoir to explore methods to monitor BMT and gather data on ebullition over 1 year. We found consistent bubble size spectra, despite large temporal variations of ebullition fluxes. We highlight some of the inherent difficulties of research in this area and argue that more experiments are needed for improving empirical and mechanistic understanding of BMT.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/feart.2023.1113349/fullTest; https://doaj.org/toc/2296-6463Test

الوصول الحر: https://doaj.org/article/bc84855d45d24bb292e223d51718e12fTest

المؤلفون: Stine Le Tougaard, Augusta Szameitat, Pauline Møs, Søren Husted

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: Solanum tuberosum, chlorophyll a fluorescence, phosphorus deficiency, nutrient remobilization, critical nutrient concentration, Plant culture, SB1-1110

الوصف: Phosphorus (P) deficiency is a global issue which can severely impact the yield of crops, including the P demanding and important food crop potato. Diagnosis of P status directly in the field can be used to adapt P fertilization strategies to the needs of the evolving crop during the growing season and is often estimated by analyzing P concentrations in leaf tissue. In this study, we investigate how diagnosis of P status in field grown potato plants is affected by leaf position and time of measurement in a randomized block experiment. The concentrations of many essential plant nutrients are highly dynamic, and large differences in nutrient concentrations were found in potato leaves depending on leaf age and time of sampling. During tuber initiation, P concentrations decreased in a steep gradient from the youngest leaves (0.8%) towards the oldest leaves (0.2%). The P concentrations in the youngest fully expanded leaf decreased by 25-33% within just 7 days, due to a high remobilization of P from source to sink tissue during crop development. 40 days later P concentrations in all leaves were near or below the established critical P concentration of 0.22%. The P concentration in leaf tissue thus depends on sampling time and leaf position on the plant, which in a practical setting might prevent a meaningful interpretation in terms of fertilizer recommendation. The chlorophyll a fluorescence parameter “P-predict”, derived from the fluorescence transients, is an alternative to the classical chemical analysis of nutrient concentrations in leaf tissue. P-predict values serve as a proxy for the bioavailable P pool in the leaf and can be measured directly in the field using handheld technology. However, in conditions of high solar irradiation, the P-predict values of the most light-exposed leaf positions, i.e. the younger leaves, were found to be severely impacted by photoinhibition, preventing accurate characterization of the P status in potatoes. Shading the plants can reverse or prevent photoinhibition and restore the diagnostic capabilities of the P-predict approach.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1100318/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/12fdf52f17b54429a051a5cacf0b86c3Test

المؤلفون: Birendra K. Padhan, Lekshmy Sathee, Santosh Kumar, Viswanathan Chinnusamy, Arvind Kumar

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: Nitrogen remobilization efficiency (NRE), Nitrogen Harvest Index (NHI), Nitrogen grain production efficiency (NUEg), Nitrogen use efficiency, Rice, NUE, Nitrogen deficiency, Optimum Nitrogen, Plant culture, SB1-1110

الوصف: Nitrogen (N) is an important macronutrient needed for grain yield, grain N and grain protein content in rice. Grain yield and quality are significantly determined by N availability. In this study, to understand the mechanisms associated with reproductive stage N remobilization and N partitioning to grain 2 years of field experiments were conducted with 30 diverse rice genotypes during 2019-Kharif and 2020-Kharif seasons. The experiments were conducted with two different N treatments; N deficient (N0-no external N application, available soil N; 2019-234.15 kgha-1, 2020-225.79 kgha-1) and N sufficient (N120-120 kgha-1 external N application, available soil N; 2019-363.77 kgha-1, 2020-367.95 kgha-1). N application increased the NDVI value, biomass accumulation, grain yield, harvest index and grain N accumulation. Post-anthesis N uptake and N remobilization from vegetative tissues to grain are critical for grain yield and N harvest index. Rice genotypes, Kalinga-1, BAM-4234, IR-8384-B-B102-3, Sahbhagi Dhan, BVD-109 and Nerica-L-42 showed a higher rate of N remobilization under N sufficient conditions. But, under N deficiency, rice genotypes-83929-B-B-291-3-1-1, BVD-109, IR-8384-B-B102-3 and BAM-4234 performed well showing higher N remobilization efficiency. The total amount of N remobilization was recorded to be high in the N120 treatment. The harvest index was higher in N120 during both the cropping seasons. RANBIR BASMATI, BAM-832, APO, BAM-247, IR-64, Vandana, and Nerica-L-44 were more efficient in N grain production efficiency under N deficient conditions. From this study, it is evident that higher grain N accumulation is not always associated with higher yield. IR-83929-B-B-291-3-1-1, Kalinga-1, APO, Pusa Basmati-1, and Nerica-L-44 performed well for different N use efficiency component traits under both N deficient (N0) and N sufficient (N120) conditions. Identifying genotypes/donors for N use efficiency-component traits is crucial in improving the fertilizer N recovery rate and site specific N management.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1093581/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/2ce3d2ffac634e88994af464ca6b8b96Test

المؤلفون: Oluwaseun Olayemi Aluko, Surya Kant, Oluwafemi Michael Adedire, Chuanzong Li, Guang Yuan, Haobao Liu, Qian Wang

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: nitrate transporters, nitrate uptake, nitrate transport and signaling, nitrate remobilization, nitrogen use efficiency, environmental stress, Plant culture, SB1-1110

الوصف: Nitrate (NO3-) transporters have been identified as the primary targets involved in plant nitrogen (N) uptake, transport, assimilation, and remobilization, all of which are key determinants of nitrogen use efficiency (NUE). However, less attention has been directed toward the influence of plant nutrients and environmental cues on the expression and activities of NO3- transporters. To better understand how these transporters function in improving plant NUE, this review critically examined the roles of NO3- transporters in N uptake, transport, and distribution processes. It also described their influence on crop productivity and NUE, especially when co-expressed with other transcription factors, and discussed these transporters’ functional roles in helping plants cope with adverse environmental conditions. We equally established the possible impacts of NO3- transporters on the uptake and utilization efficiency of other plant nutrients while suggesting possible strategic approaches to improving NUE in plants. Understanding the specificity of these determinants is crucial to achieving better N utilization efficiency in crops within a given environment.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1074839/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/f9b597b8cc484205984919cd864e6f42Test

المؤلفون: Feifan Lin, Sheng Lin, Zhixing Zhang, Wenxiong Lin, Christopher Rensing, Daoxin Xie

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: ratooning season rice, GF14f gene, carbon reserve remobilization, starch composition, oxidative and environmental resistance, Plant culture, SB1-1110

الوصف: BackgroundRatoon rice cropping has been shown to provide new insights into overcoming the current challenges of rice production in southern China. However, the potential mechanisms impacting yield and grain quality under rice ratooning remain unclear.MethodsIn this study, changes in yield performance and distinct improvements in grain chalkiness in ratoon rice were thoroughly investigated, using physiological, molecular and transcriptomic analysis.ResultsRice ratooning induced an extensive carbon reserve remobilization in combination with an impact on grain filling, starch biosynthesis, and ultimately, an optimization in starch composition and structure in the endosperm. Furthermore, these variations were shown to be associated with a protein-coding gene: GF14f (encoding GF14f isoform of 14-3-3 proteins) and such gene negatively impacts oxidative and environmental resistance in ratoon rice.ConclusionOur findings suggested that this genetic regulation by GF14f gene was the main cause leading to changes in rice yield and grain chalkiness improvement of ratoon rice, irrespective of seasonal or environmental effects. A further significance was to see how yield performance and grain quality of ratoon rice were able to be achieved at higher levels via suppression of GF14f.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1112146/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/935b514d7d2043b1a08e028829cb1f8bTest

المؤلفون: Yasuhito Sakuraba

المصدر: Frontiers in Plant Science, Vol 13 (2022)

مصطلحات موضوعية: leaf senescence, nitrogen (N), N starvation, N remobilization, transcriptional regulation, Plant culture, SB1-1110

الوصف: Nitrogen (N), a macronutrient, is often a limiting factor in plant growth, development, and productivity. To adapt to N-deficient environments, plants have developed elaborate N starvation responses. Under N-deficient conditions, older leaves exhibit yellowing, owing to the degradation of proteins and chlorophyll pigments in chloroplasts and subsequent N remobilization from older leaves to younger leaves and developing organs to sustain plant growth and productivity. In recent years, numerous studies have been conducted on N starvation-induced leaf senescence as one of the representative plant responses to N deficiency, revealing that leaf senescence induced by N deficiency is highly complex and intricately regulated at different levels, including transcriptional, post-transcriptional, post-translational and metabolic levels, by multiple genes and proteins. This review summarizes the current knowledge of the molecular mechanisms associated with N starvation-induced leaf senescence.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2022.1013304/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/da0a5bab872e46ca8774e15dfb457387Test

المؤلفون: Vivek Shrestha, Hari B. Chhetri, David Kainer, Yaping Xu, Lance Hamilton, Cristiano Piasecki, Ben Wolfe, Xueyan Wang, Malay Saha, Daniel Jacobson, Reginald J. Millwood, Mitra Mazarei, C. Neal Stewart

المصدر: Frontiers in Plant Science, Vol 13 (2022)

مصطلحات موضوعية: nitrogen use efficiency, nitrogen remobilization efficiency, switchgrass, accessions, genome wide association study, Plant culture, SB1-1110

الوصف: Switchgrass (Panicum virgatum L.) has immense potential as a bioenergy crop with the aim of producing biofuel as an end goal. Nitrogen (N)-related sustainability traits, such as nitrogen use efficiency (NUE) and nitrogen remobilization efficiency (NRE), are important factors affecting switchgrass quality and productivity. Hence, it is imperative to develop nitrogen use-efficient switchgrass accessions by exploring the genetic basis of NUE in switchgrass. For that, we used 331 diverse field-grown switchgrass accessions planted under low and moderate N fertility treatments. We performed a genome wide association study (GWAS) in a holistic manner where we not only considered NUE as a single trait but also used its related phenotypic traits, such as total dry biomass at low N and moderate N, and nitrogen use index, such as NRE. We have evaluated the phenotypic characterization of the NUE and the related traits, highlighted their relationship using correlation analysis, and identified the top ten nitrogen use-efficient switchgrass accessions. Our GWAS analysis identified 19 unique single nucleotide polymorphisms (SNPs) and 32 candidate genes. Two promising GWAS candidate genes, caffeoyl-CoA O-methyltransferase (CCoAOMT) and alfin-like 6 (AL6), were further supported by linkage disequilibrium (LD) analysis. Finally, we discussed the potential role of nitrogen in modulating the expression of these two genes. Our findings have opened avenues for the development of improved nitrogen use-efficient switchgrass lines.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2022.893610/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/9185869882da4284ac1629bd48642a72Test