Translocation Of Photosynthates Research Articles

Development of a compact multiprobe system for monitoring positron-emitting tracers in plant stems

Nondestructive monitoring of positron-emitting tracers in plant bodies at multiple points, including points separated by large distances, has been realised with the positron multiprobe system (PMPS) to investigate graminaceous plants, whose stems and leaves have simple shapes. Recently, the translocation of photosynthates into fruits has been studied intensively using a 11C tracer. The relatively complex shapes of the stems and leaves of these plants sometimes prevent the detector heads of the PMPS from approaching and being fixed to the target stem properly because of its relatively large and heavy detector heads based on photomultiplier tubes. Owing to the compactness, lightweightness and recent advances of silicon photomultipliers (SiPMs), fabricating compact and lightweight detector heads has become possible. In this study, we developed a compact PMPS (CPMPS) using SiPMs and successfully demonstrated its capability for monitoring a 11C tracer in strawberry stems. Moreover, we found that energy-window filtering markedly reduced noise events without radiation shielding. The dominant ionisation events detected by the CPMPS were Compton scattering and subsequent photoabsorption of a single 511 keV gamma ray, suggesting that the ionisation events of single-gamma-ray emitters, such as 42K, 43K, 54Mn, 59Fe and 65Zn, can be detected by the CPMPS. The developed CPMPS can also be applied to study the physiology of other plants with intricately shaped stems and leaves, such as the tomato and eggplant.

Comparative physiology reveals heat stress disrupts acid-base homeostasis independent of symbiotic state in the model cnidarian Exaiptasia diaphana.

Climate change threatens the survival of symbiotic cnidarians by causing photosymbiosis breakdown in a process known as bleaching. Direct effects of temperature on cnidarian host physiology remain difficult to describe because heatwaves depress symbiont performance, leading to host stress and starvation. The symbiotic sea anemone Exaiptasia diaphana provides an opportune system to disentangle direct versus indirect heat effects on the host, as it can survive indefinitely without symbionts. We tested the hypothesis that heat directly impairs cnidarian physiology by comparing symbiotic and aposymbiotic individuals of two laboratory subpopulations of a commonly used clonal strain of E. diaphana, CC7. We exposed anemones to a range of temperatures (ambient, +2°C, +4°C and +6°C) for 15-18 days, then measured their symbiont population densities, autotrophic carbon assimilation and translocation, photosynthesis, respiration and host intracellular pH (pHi). Symbiotic anemones from the two subpopulations differed in size and symbiont density and exhibited distinct heat stress responses, highlighting the importance of acclimation to different laboratory conditions. Specifically, the cohort with higher initial symbiont densities experienced dose-dependent symbiont loss with increasing temperature and a corresponding decline in host photosynthate accumulation. In contrast, the cohort with lower initial symbiont densities did not lose symbionts or assimilate less photosynthate when heated, similar to the response of aposymbiotic anemones. However, anemone pHi decreased at higher temperatures regardless of cohort, symbiont presence or photosynthate translocation, indicating that heat consistently disrupts cnidarian acid-base homeostasis independent of symbiotic status or mutualism breakdown. Thus, pH regulation may be a critical vulnerability for cnidarians in a changing climate.

Irradiance driven trophic plasticity in the coral Madracis pharensis from the Eastern Mediterranean

The distribution of symbiotic scleractinian corals is driven, in part, by light availability, as host energy demands are partially met through translocation of photosynthate. Physiological plasticity in response to environmental conditions, such as light, enables the expansion of resilient phenotypes in the face of changing environmental conditions. Here we compared the physiology, morphology, and taxonomy of the host and endosymbionts of individual Madracis pharensis corals exposed to dramatically different light conditions based on colony orientation on the surface of a shipwreck at 30 m depth in the Bay of Haifa, Israel. We found significant differences in symbiont species consortia, photophysiology, and stable isotopes, suggesting that these corals can adjust multiple aspects of host and symbiont physiology in response to light availability. These results highlight the potential of corals to switch to a predominantly heterotrophic diet when light availability and/or symbiont densities are too low to sustain sufficient photosynthesis, which may provide resilience for corals in the face of climate change.

Phenotypic Variations in Banana Cultivars in the Utilization and Tolerance to Different Magnesium Levels

Magnesium (Mg) is the most commonly deficient nutrient in tropical banana-growing areas. The effects of different concentrations of Mg on morpho-physiological and biochemical responses on three commercial cultivars (Baxi, Haigong, and Guangfen No.1) of bananas were accessed for 12 weeks. Results showed genotypic variation in the utilization and tolerance to different Mg levels. The optimum Mg level was 1 mM for Baxi and Guangfen No.1 and 3 mM for Haigong. Both the deficiency and excess of Mg caused a severe reduction in plant height, dry weight, total root length, and root surface area of Haigong and Baxi. Mg stress reduced root growth by impairing photosynthate translocation and increased carbohydrate contents in the source leaf. Under Mg stress, more reduction in photosynthetic pigment and photosynthesis rate, higher accumulation of carbohydrates and malondialdehyde contents, and higher activities of antioxidative enzymes were observed in Haigong as compared to other genotypes. Based on the above results, it is concluded that Haigong is most sensitive to Mg stress while Guangfen No. 1 was least affected and tolerant to changes in the Mg levels.

Translocation of 11C-labelled photosynthates to strawberry fruits depends on leaf transpiration during twilight

Photosynthate translocation from leaves to fruits is an important determinant of crop yield and quality. In protected cultivation, environmental control based on photosynthate translocation is indicative for realising high-yield and high-quality production. There are, however, few studies on the environmental response of photosynthate translocation, especially during twilight. In greenhouses, these transition periods are characterised by a drastic change in relative humidity (RH). In this study, we focused on light intensity as a key environmental factor to steer translocation under high RH prevailing under twilight conditions. We fed 11CO2 to a leaf of strawberry plants (Fragaria × ananassa Duch.) and analysed real-time dynamics of 11C-labeled photosynthate translocation to individual fruits on an inflorescence of intact plants by using positron emission tomography (PET) under different light intensities (i.e., 50, 200 and 400 μmol m−2 s−1). No clear relationship was obtained between 11C-photosynthate translocation and light intensity since the results revealed that translocation rates into the fruits were highest under the light intensity of 200 μmol m−2 s−1 followed by those of 400 and 50 μmol m−2 s−1. However, there was a strong negative correlation between transpiration rate of the 11C-fed leaf and 11C-photosynthate translocation rate. These novel findings indicate that transpiration, which controls leaf moisture status, is one of the drivers for photosynthate translocation towards fruits during twilight conditions.

Rice immediately adapts the dynamics of photosynthates translocation to roots in response to changes in soil water environment.

Rice is susceptible to abiotic stresses such as drought stress. To enhance drought resistance, elucidating the mechanisms by which rice plants adapt to intermittent drought stress that may occur in the field is an important requirement. Roots are directly exposed to changes in the soil water condition, and their responses to these environmental changes are driven by photosynthates. To visualize the distribution of photosynthates in the root system of rice plants under drought stress and recovery from drought stress, we combined X-ray computed tomography (CT) with open type positron emission tomography (OpenPET) and positron-emitting tracer imaging system (PETIS) with 11C tracer. The short half-life of 11C (20.39min) allowed us to perform multiple experiments using the same plant, and thus photosynthate translocation was visualized as the same plant was subjected to drought stress and then re-irrigation for recovery. The results revealed that when soil is drier, 11C-photosynthates mainly translocated to the seminal roots, likely to promote elongation of the root with the aim of accessing water stored in the lower soil layers. The photosynthates translocation to seminal roots immediately stopped after rewatering then increased significantly in crown roots. We suggest that when rice plant experiencing drought is re-irrigated from the bottom of pot, the destination of 11C-photosynthates translocation immediately switches from seminal root to crown roots. We reveal that rice roots are responsive to changes in soil water conditions and that rice plants differentially adapts the dynamics of photosynthates translocation to crown roots and seminal roots depending on soil conditions.

Coral holobiont research needs spatial analyses at the microbial scale.

Coral holobiont research needs spatial analyses at the microbial scale.

Using Stable Isotope Analyses to Assess the Trophic Ecology of Scleractinian Corals

Studies on the trophic ecology of scleractinian corals often include stable isotope analyses of tissue and symbiont carbon and nitrogen. These approaches have provided critical insights into the trophic sources and sinks that are essential to understanding larger-scale carbon and nitrogen budgets on coral reefs. While stable isotopes have identified most shallow water (<30 m) corals as mixotrophic, with variable dependencies on autotrophic versus heterotrophic resources, corals in the mesophotic zone (~30–150 m) transition to heterotrophy with increasing depth because of decreased photosynthetic productivity. Recently, these interpretations of the stable isotope data to distinguish between autotrophy and heterotrophy have been criticized because they are confounded by increased nutrients, reverse translocation of photosynthate, and changes in irradiance that do not influence photosynthate translocation. Here we critically examine the studies that support these criticisms and show that they are contextually not relevant to interpreting the transition to heterotrophy in corals from shallow to mesophotic depths. Additionally, new data and a re-analysis of previously published data show that additional information (e.g., skeletal isotopic analysis) improves the interpretation of bulk stable isotope data in determining when a transition from primary dependence on autotrophy to heterotrophy occurs in scleractinian corals.

Different survival strategies involve carbon translocation rather than de novo C assimilation under complete submergence in rice plant.

This study investigated the effect of transient submergence on the recovery of photosynthetic activity and translocation of photosynthate in IR67520 (Sub1A genotype) and IR72442 (non-Sub1A genotype) using 13C-labeled tracer, coupled with some photosynthetic physiological assessments. Plant growth, photosynthetic capacity, and photosynthetic recovery were studied by treating the two rice genotypes without or completely submerged for 7days in transparent acrylic tanks filled with water to a depth of 80cm, followed by 7days of reaeration. Results revealed that the IR67520 was able to obtain new carbon source for assimilation during at 7days of recovery periods. The IR72442 genotype partitioned 13C to the newly developed upper leaves more than the IR67520 genotype did. This was due to its inability to obtain CO2 from other source during post submergence. Recovery of chlorophyll content, ability to retain higher biomass, and ability to grow faster at 7days of recovery periods also indicated the ability of Sub1A genotype to reactivate its photosynthetic capacity.

Impact of Rising Atmospheric Temperature on Wheat

Since the industrial revolution, temperatures have been steadily rising over the world at a pace of 0.15 to 0.17°Cevery decade. The productivity of agricultural crops is being impacted. To maintain crop output under increased temperatures, thermotolerance measures are therefore required. More than 80% of the world's population relies on wheat, a significant grain crop, as a source of essential protein and calories. Concerns about how rising temperatures could affect wheat output due to recent global climate change are spreading around the globe. Abiotic stressors such as heat and drought are what primarily limit wheat productivity. Under projected future climatic scenarios, extreme weather events (such as frost and heat shock), which presently pose a considerable burden to grain growers, are expected to get worse. The crucial physiological and biochemical processes of the plant are halted by heat stress. Stress brought on by high temperatures decreases the quantity of grains, photosynthetic activity, chlorophyll content, and endosperm starch synthesis. The high temperature has a negative impact on the phenology, growth, and development of the crop. The pollen viability, seed germination, and embryo development are all slowed down by the high temperature before anthesis. The accumulation of starch granules, stem reserve carbohydrates, and photosynthate translocation into grains are all reduced by the high postanthesis temperature. A temperature above 400°C prevents photosynthesis from happening by harming photosystem-I, photosystem-II, and the electron transport chain. The crop suffers significant oxidative damage when reactive oxygen species that have accumulated due to heat stress. In order to reduce the effects of heat stress, plants quickly synthesise heat shock proteins.

Examining effects of rhizobacteria in relieving abiotic crop stresses using carbon‐11 radiotracing

In agriculture, plant growth promoting bacteria (PGPB) are increasingly used for reducing environmental stress‐related crop losses through mutualistic actions of these microorganisms, activating physiological and biochemical responses, building tolerances within their hosts. Here we report the use of radioactive carbon‐11 (t ½ 20.4 min) to examine the metabolic and physiological responses of Zea mays to Azospirillum brasilense (HM053) inoculation while plants were subjected to salinity and low nitrogen stresses. Host metabolism of “new” carbon resources (as 11C) and physiology including [11C]‐photosynthate translocation were measured in response to imposed growth conditions. Salinity stress caused shortened, dense root growth with a 6‐fold increase in foliar [11C]‐raffinose, a potent osmolyte. ICP‐MS analyses revealed increased foliar Na+ levels at the expense of K+. HM053 inoculation relieved these effects, reinstating normal root growth, lowering [11C]‐raffinose levels while increasing [11C]‐sucrose and its translocation to the roots. Na+ levels remained elevated with inoculation, but K+ levels were boosted slightly. Low nitrogen stress yielded longer roots possessing high levels of anthocyanins. Metabolic analysis revealed significant shifts in “new” carbon partitioning into the amino acid pool under low nitrogen stress, with significant increases in foliar [11C]‐glutamate, [11C]‐aspartate, and [11C]‐asparagine, a noted osmoprotectant. 11CO2 fixation and [11C]‐photosynthate translocation also decreased, limiting carbon supply to roots. However, starch levels in roots were reduced under nitrogen limitation, suggesting that carbon repartitioning could be a compensatory action to support root growth. Finally, inoculation with HM053 re‐instated normal root growth, reduced anthocyanin, boosted root starch, and returned 11C‐allocation levels back to those of unstressed plants.

Plant root PET: visualization of photosynthate translocation to roots in rice plant

Roots are essential to plants for uptake of water and nutrients. For the improvement of crop production, it is necessary to understand the elucidation of the root development and its function under the ground. Especially, photosynthate translocation from plant leaves to roots is an important physiological function that affects the root elongation, adaptation to the soil environment and nutrients uptake. To evaluate the translocation dynamics to roots, positron emission tomography (PET) and 11C tracer have been used. However, the spatial resolution is degraded at roots that develop around the peripheral area of field of view (FOV) due to parallax errors. In this study, to overcome this problem, we developed a small OpenPET prototype applying four-layer depth-of-interaction detectors. We demonstrated the imaging capability of 11C-photosynthate translocation to rice roots that develop throughout the entire PET field. We also tried to obtain structural information of roots by high-throughput X-ray computerized tomography (CT) system using the same test plant. As a result, we succeeded in visualizing the root structure that developed around the peripheral region of FOV and imaging the accumulation of 11C-photosynthate to the roots in those areas without degrading the spatial resolution. From obtained images, we also succeeded in evaluating the translocation dynamics varied by roots. The combined use of the high-throughput CT system and the OpenPET prototype was demonstrated to be appropriate for structural and functional analysis of roots.

Effects of nitrogen addition on clonal integration between mother and daughter ramets of Moso bamboo: a 13C-CO2 pulse labeling study

Abstract Resource sharing among connected ramets (i.e. clonal integration) is one of the distinct traits of clonal plants. Clonal integration confers Moso bamboo (Phyllostachys pubescens) a strong adaptability to different environmental conditions. But the mechanisms of how clonal integration makes Moso bamboo has better performance are still poorly understood. In this study, acropetal and basipetal translocation of photosynthates between Moso bamboo ramets were analyzed separately to investigate how clonal fragments obtain higher benefits under heterogeneous N conditions. Clonal fragments of Moso bamboo consisting of two interconnected mother–daughter ramets were used, each of the ramets was subjected to either with or without N addition. The acropetal and basipetal translocation of 13C-photosynthates was separated via single-ramet 13CO2-labeling. Mother ramets translocated more 13C-photosynthates to daughter ramets with N addition, and the translocation of 13C-photosynthates to mother ramets was more pronounced when daughter ramets were treated with N addition. The 13C-photosynthates that were translocated from mother ramets without and with N addition were mainly invested in the leaves and roots of daughter ramets with N addition, from daughter ramets with N addition were mainly invested in the leaves and roots of mother ramets with and without N addition, respectively. These results suggest that mother ramets preferentially invest more resources in nutrient-rich daughter ramets, and that daughter ramets serve as efficient resource acquisition sites to specialize in acquiring abundant resources based on the resource conditions of mother ramets. Clonal plants can improve their resource acquisition efficiency and maximize the overall performance in this way.

Photosynthesis from stolen chloroplasts can support sea slug reproductive fitness.

Some sea slugs are able to steal functional chloroplasts (kleptoplasts) from their algal food sources, but the role and relevance of photosynthesis to the animal host remain controversial. While some researchers claim that kleptoplasts are slowly digestible ‘snacks’, others advocate that they enhance the overall fitness of sea slugs much more profoundly. Our analysis shows light-dependent incorporation of 13C and 15N in the albumen gland and gonadal follicles of the sea slug Elysia timida, representing translocation of photosynthates to kleptoplast-free reproductive organs. Long-chain polyunsaturated fatty acids with reported roles in reproduction were produced in the sea slug cells using labelled precursors translocated from the kleptoplasts. Finally, we report reduced fecundity of E. timida by limiting kleptoplast photosynthesis. The present study indicates that photosynthesis enhances the reproductive fitness of kleptoplast-bearing sea slugs, confirming the biological relevance of this remarkable association between a metazoan and an algal-derived organelle.

Remarkable Metabolic Reconfiguration due to N Deficiency and an Ammonium‐to‐Nitrate Shift in the Free‐Living Effrenium voratum (Symbiodiniaceae)

AbstractNitrogen (N) controls the growth of phytoplankton and the phytosymbionts of corals, but little is known about N nutrition in free‐living planktonic species of the Symbiodiniaceae family. Here, with physiological and transcriptomic analyses, we investigated how Effrenium voratum responded to N deficiency or a nitrate (NO3−) to ammonium (NH4+) switch. The results from batch cultures showed that E. voratum grew well on both NH4+ and NO3−, but NH4+ supported higher yield. Furthermore, when provided with both NH4+ and NO3−, E. voratum preferentially utilized NH4+ and consumed it faster than NO3−. Inhibitory effects of NH4+ on cell growth and photochemical efficiency were detected at ≥ 440 μM in a dose‐dependent manner. When NH4+ and NO3− were compared, only 582 genes were differentially expressed; NH4+ promoted expression of genes related to N transport, carbon fixation, chlorophyll synthesis, and cell division. In contrast, N deficiency inhibited cell division, decreased Chl a content, and changed expression of a large number (4,553) of genes involved in a wide range of metabolic processes from N acquisition, carbon fixation, photosynthate translocation, glycolysis, ROS production, to the cell cycle. This study provides baseline information about N nutrition in a free‐living symbiodiniacean dinoflagellate, which will be useful for comparative research with symbiotic counterparts. The findings also underscore the need to consider differences among phytoplankton groups in responding to forms (NH4+ versus NO3−) and availability (N repletion versus deficiency) of N‐nutrient in modeling N effects on phytoplankton dynamics.

Genetic and physiological traits conferring tolerance to ocean acidification in mesophotic corals.

The integrity of coral reefs worldwide is jeopardized by ocean acidification (OA). Most studies conducted so far have focused on the vulnerability to OA of corals inhabiting shallow reefs while nothing is currently known about the response of mesophotic scleractinian corals. In this study, we assessed the susceptibility to OA of corals, together with their algal partners, inhabiting a wide depth range. We exposed fragments of the depth generalist coral Stylophora pistillata collected from either 5 or 45m to simulated future OA conditions, and assessed key molecular, physiological and photosynthetic processes influenced by the lowered pH. Our comparative analysis reveals that mesophotic and shallow S. pistillata corals are genetically distinct and possess different symbiont types. Under the exposure to acidification conditions, we observed a 50% drop of metabolic rate in shallow corals, whereas mesophotic corals were able to maintain unaltered metabolic rates. Overall, our gene expression and physiological analyses show that mesophotic corals possess a greater capacity to cope with the effects of OA compared to their shallow counterparts. Such capability stems from physiological characteristics (i.e., biomass and lipids energetics), a greater capacity to regulate cellular acid-base parameters, and a higher baseline expression of cell adhesion and extracellular matrix genes. Moreover, our gene expression analysis suggests that the enhanced symbiont photochemical efficiency under high pCO2 levels could prevent acidosis of the host cells and it could support a greater translocation of photosynthates, increasing the energy pool available to the host. With this work, we provide new insights on the response to OA of corals living at mesophotic depths. Our investigation discloses key genetic and physiological traits underlying the potential for corals to cope with future OA conditions.

Non-invasive 11C-Imaging Revealed the Spatiotemporal Variability in the Translocation of Photosynthates Into Strawberry Fruits in Response to Increasing Daylight Integrals at Leaf Surface.

The efficiency of photosynthate translocation from leaves to fruits directly affects dry matter partitioning. Therefore, controlling photosynthate translocation dynamics is critical for high-yield and high-quality fruit production. Accordingly, photosynthate translocation changes must be characterized using data obtained at a higher spatiotemporal resolution than those provided by conventional methods. In this study, 11C-photosynthate translocation into strawberry (Fragaria × ananassa Duch.) fruits in individual plants was visualized non-invasively and repeatedly using a positron emission tracer imaging system (PETIS) to assess the spatiotemporal variability in the translocation dynamics in response to increasing daylight integrals (i.e., 0.5-, 4.5-, and 9-h exposures to 400 μmol m–2 s–1 at the leaf surface). Serial images of photosynthate translocation into strawberry fruits obtained from the PETIS confirmed that 11C-photosynthates were translocated heterogeneously into each fruit on the same inflorescence. The amount of translocated 11C-photosynthates and the translocation rate into each fruit significantly increased as the integrated light intensity at the leaf surface increased. An analysis of the pedicel of each fruit also confirmed that the photosynthate translocation rate increased. The cumulated photosynthesis in leaves increased almost linearly during the light period, suggesting that an increase in the amount of photosynthates in leaves promotes the translocation of photosynthates from leaves, resulting in an increase in the photosynthate translocation rate in pedicels and enhanced photosynthate accumulation in fruits. Additionally, the distribution pattern of photosynthate translocated to fruits did not change during the light period, nor did the order of the sink activity (11C radioactivity/fruit dry weight), which is the driving force for the prioritization of the 11C-partitioning between competing organs, among fruits. Thus, this is the first study to use 11C-radioisotopes to clarify the spatiotemporal variability in photosynthate translocation from source leaves to individual sink fruits in vivo in response to increasing daylight integrals at a high spatiotemporal resolution.

Effects of zinc levels on synthesis and translocation of 13C-photoassimilates in leaves to fruit of apple during fruit expanding stage

To explore the effects of zinc levels on the synthesis and translocation of photosynthetic products from leaves to fruits, and to lay a theoretical foundation for improving fruit quality through zinc supplementation during the critical period of apple fruit development, a field experiment was carried out with a eight-year old 'Hanfu'/GM256/Malus baccata Borkh apple. We used the 13C tracer method to examine the effects of different zinc levels (ZnSO4·H2O 0, 0.1%, 0.2%, 0.3%, 0.4%, expressed by CK, Zn1, Zn2, Zn3, Zn4, respectively) on translocation of photosynthate to fruit during the stage of fruit expanding. The results showed that, with increasing zinc concentration, Rubisco enzyme activity, net photosynthetic rate, sorbitol and sucrose content, sorbitol 6-phosphate dehydrogenase, and sucrose phosphate synthase enzyme activities of leaves first increased and then decreased, with the highest values being observed in Zn3 treatment. Zn3 treatment significantly increased the 13C assimilation capability of leaves. Compared with other treatments, the 13C of self-retention (labeled leaves and labeled branches) was lowest in Zn3 treatment (61.2%) and the output of 13C photoassimilates was highest in Zn3 treatment (38.8%). 13C absorption of apple fruit showed a trend of Zn3 ＞ Zn2 ＞ Zn4 ＞ Zn1 ＞ CK. In summary, foliar zinc application under appropriate concentration (0.3% ZnSO4·H2O) enhanced photosynthesis, increased the assimilation capability of leaves, and promoted the directional transportation of photosynthate to fruit.

HEAT STRESS EFFECT ON WHEAT: A REVIEW

Heat stress is the main limiting factors for wheat production worldwide. Raising of temperature above 31°C during grain filling causes heat stress. Every 1°C rise in temperature reduced the wheat production by 6%. Under heat stress, the plant highly produced reactive element known as oxygen reactive species. ROS disturbs the function of the cell by their negative action on lipids, protein and DNA. Heat stress disrupt the plant water relation, cell turgidity, reduced seed germination and seedling growth, deactivation of photosynthetic enzymes, disturb translocation of photosynthate due to which it reduced grain number and grain filling. Management approaches like agronomic management and genetic management can be applied against heat stress. The main objective of this review is to study the responses of wheat towards heat stress and its management practices.

Split application of potassium improves yield and potassium uptake of rice under deficient soils

Potassium is involved in many vital plant functions improving grain quality, water and nutrient use efficiency, stress tolerance, energy-use efficiency, translocation of photosynthates and sugars from source to sink. The experimental site lies in the area of K-deficient region in the Punjab state, India. A two year (2016–17 and 2017–18) field experiment was conducted to assess the impact of split application of K on growth, yield and K uptake. The experiment comprising six treatments of K fertilizer application with four replications was laid out in a randomized complete block design. The results revealed significant improvement in growth and yield parameters of rice crop when numbers of splits were increased from single basal dose to two and three splits. The data further revealed a significant improvement in the total uptake of K(grain + straw) with three splits as compared to control application and single split application. The data on partial K budget revealed higher K removal where grain and biomass yield were higher in three split doses of K than that in control and single split application. The agronomic efficiency showed that the three split doses of potassium fertilizers may be recommended to achieve better yield and potassium use efficiency. The study highlights the need to study the complete potassium budget of crop for sustainable crop production.