Overexpression of ADP-glucose pyrophosphorylase in both leaf and seed tissue synergistically increase biomass and seed number in rice (Oryza sativa ssp. japonica)

2016 ◽  
Vol 43 (12) ◽  
pp. 1194 ◽  
Author(s):  
Alanna J. Oiestad ◽  
John M. Martin ◽  
Michael J. Giroux

Increased expression of leaf or seed ADPglucose pyrophosphorylase activity (AGPase) has been shown to increase plant growth. However, no study has directly compared AGPase overexpression in leaves and/or seeds. In the present study, transgenic rice overexpressing AGPase in leaves or in seeds were crossed, resulting in four F2:3 homozygous genotypes with AGPase overexpression in leaves, seeds, both leaves and seeds, or neither tissue. The impact of AGPase overexpression in these genotypic groups was examined at the metabolic, transcriptomic, and plant growth levels. Leaf-specific AGPase overexpression increased flag leaf starch up to five times that of the wild type (WT) whereas overexpression of AGPase in both leaves and seeds conferred the greatest productivity advantages. Relative to the WT, AGPase overexpression in both leaves and seeds increased plant biomass and panicle number by 61% and 51%, respectively while leaf-specific AGPase overexpression alone only increased plant biomass and panicle number by 24 and 32% respectively. Extraction and analysis of RNA and leaf-specific metabolites demonstrated that carbon metabolism was broadly increased by AGPase overexpression in seeds and leaves. These findings indicate that stimulation of whole-plant growth and productivity can be best achieved by upregulation of starch biosynthesis in both leaves and seeds.


Author(s):  
L. M. Manici ◽  
F. Caputo ◽  
G. A. Cappelli ◽  
E. Ceotto

Abstract Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).



2013 ◽  
Vol 2 ◽  
pp. 139-148 ◽  
Author(s):  
JD Ranjit ◽  
R Bellinder ◽  
C Benidict ◽  
V Kumar

Greenhouse studies were initiated in two small (Polypogon fugox) and large (Phalaris minor) seeded annual grasses in 2007 at Cornell University, Ithaca, NY USA. These two annual grasses were very common in wheat fields of midhills and terai regions of Nepal. P fugox was taken for biological study. Days to emergence took 8-11 days in green house. Early emerged panicles were longer than those emerged late. Panicle took 10-12 days to emerge completely from the flag leaf. Panicles per plant were 120. Seeds were very small having about 1091 seeds per panicle. So one fully matured plant could produce seeds about 130920. Study on eco-biology needs to continue in the future. P fugox and P minor responded differently to buckwheat residues. Among different treatments emergence and growth of both weeds were suppressed more by buckwheat residues when left on the surface than incorporated. P minor was less affected by buckwheat residues. It might be due to larger seed compared to P fugox. Post emergence herbicides clodinofop and pinoxaden were effective on both grasses. Isoproturon and tralkoxydim were effective on P fugox. Sulfosulfuron was good in reducing plant growth to some extent. Preemergence herbicides pendimethalin and s-metolochlor were effective in reducing emergence and growth of both weeds. Isoproturon and and sulfosulfuron suppressed plant growth reducing dry plant biomass. DOI: http://dx.doi.org/10.3126/ajn.v2i0.7529 Agronomy Journal of Nepal (Agron JN) Vol. 2: 2011 pp.139-148



Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1429
Author(s):  
Tadeja Savi ◽  
Jose Carlos Herrera ◽  
Astrid Forneck

Phylloxera is one of the most invasive and widespread insects in viticulture. An increase in populations feeding on leaves and/or roots of formerly resistant grapevines has been observed, but information on leaf and whole plant phylloxera infestation effects is lacking. We monitored the water and carbon metabolism of vines (one rootstock x scion combination) inoculated with insects’ eggs on leaves (L) or both leaves and roots (R+L). Nonstructural carbohydrates (NSC) in infested and noninfested tissue of different organs and plant biomass were measured at the end of the experiment. At the peak of the biotic stress treatment, the plants reduced transpiration by about 30% compared to control, while photosynthesis remained unaffected. Lower soluble NSC were measured in infested than in the nearby noninfested tissue of both L and R+L groups, suggesting sugar consumption by the insect, while infested roots increased starch content by fivefold. NSC were depleted in noninfested roots of R+L plants as well, giving strength to the hypothesis of intense metabolites translocation in favor of the insect. A more distinct physiological depression in R+L vines compared to L was highlighted, even if the total biomass reduction was more marked in L plants. Our preliminary results suggest that the insect reprograms plant metabolism stimulating a more conservative water use, while competing with the host plant for carbon resources. Further studies should validate current results and quantify the NSC invested in the plant’s defense against the pest.



2017 ◽  
Author(s):  
Hannah R. Belsham ◽  
Claire T. Friel

AbstractThe microtubule depolymerising kinesin-13, MCAK, is phosphorylated at residue T537 by Cdk1. This is the only known phosphorylation site within MCAK’s motor domain. To understand the impact of phosphorylation by Cdk1 microtubule depolymerisation activity, we have investigated the molecular mechanism of the phosphomimic mutant T537E. This mutant significantly impairs microtubule depolymerisation activity and when transfected into cells causes metaphase arrest and misaligned chromosomes. We show that the molecular mechanism underlying the reduced depolymerisation activity of this phosphomimic mutant is an inability to recognise the microtubule end. The microtubule-end residence time is reduced relative to wild-type MCAK, whereas the lattice residence time is unchanged by the phosphomimic mutation. Further, the microtubule-end specific stimulation of ADP dissociation, characteristic of MCAK, is abolished by this mutation. Our data shows that T537E is unable to distinguish between the microtubule end and the microtubule lattice.



2020 ◽  
Author(s):  
David Robinson

AbstractUsing a simple plant growth model based on the logistic equation I re-evaluate how biomass allocation between roots and shoots articulates dynamically with the rate of whole-plant biomass production. Defined by parameters reflecting lumped physiological properties, the model constrains roots and shoots to grow sigmoidally over time. From those temporal patterns detailed trajectories of allocation and growth rate are reconstructed. Sigmoid growth trajectories of roots and shoots are incompatible with the dominant ‘functional equilibrium’ model of adaptive allocation and growth often used to explain plants’ responses to nutrient shortage and defoliation. Anything that changes the differential rates of growth between roots and shoots will automatically change allocation and, unavoidably, change whole-plant growth rate. Biomass allocation and whole-plant growth rate are not independent traits. Allocation and growth rate have no unique relationship to one another but can vary across a wide spectrum of possible relationships. When root-shoot allocation seems to respond to the environment it is likely to be a secondary illusory consequence of other primary responses such as localised root proliferation in soil or leaf expansion within canopy gaps. Changes in root-shoot allocation cannot themselves compensate directly for an impairment of growth rate caused by an external factor such as nutrient shortage or defoliation; therefore, such changes cannot be ‘adaptive’.‘The reasons are so simple they often escape notice.’ (James 2012, p. 6).



2021 ◽  
Author(s):  
MENGZI ZHANG ◽  
Abhisheak Sharma ◽  
Francisco León ◽  
Bonnie Avery ◽  
Roger Kjelgren ◽  
...  

The dose-dependent consumptive effect of kratom and its potential application as an alternative source of medicine to mitigate opioid withdrawal symptoms has brought considerable attention to this plant. Increased interest in the application and use of kratom has emerged globally, including North America. Although the chemistry and pharmacology of major kratom alkaloids, mitragynine and 7-hydroxymitragynine, are well documented, foundational information on the impact of plant production environment on growth and kratom alkaloids synthesis is unavailable. To directly address this need, kratom plant growth, leaf chlorophyll content, and alkaloid concentration were evaluated under three lighting conditions: outdoor full sun, greenhouse unshaded, and greenhouse shaded. Nine kratom alkaloids were quantified using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. Contents of six alkaloids to include: mitragynine, speciogynine, speciociliatine, mitraphylline, coynantheidine, and isocorynantheidine were not significantly impacted by lighting conditions, whereas 7-hydroxymitragynine was below the lower limit of quantification across all treatments. However, paynantheine concentration per leaf dry mass was increased by 40% and corynoxine was increased by 111% when grown under shade conditions in a greenhouse compared to outdoor full sun. Additionally, total alkaloid yield per plant was maximized when plants were under such conditions. Greenhouse cultivation generally promoted height and width extension, leaf number, leaf area, average leaf size, and total leaf dry mass, compared to outdoor full sun condition. Rapid, non-destructive chlorophyll evaluation correlated well (r2 = 0.68) with extracted chlorophyll concentrations. Given these findings, production efforts where low-light conditions can be implemented are likely to maximize plant biomass and total leaf alkaloid production.



2019 ◽  
Author(s):  
Wheaton L. Schroeder ◽  
Rajib Saha

AbstractStoichiometric Models of metabolism have proven valuable tools for increased understanding of metabolism and accuracy of synthetic biology interventions to achieve desirable phenotypes. Such models have been used in conjunction with optimization-based and have provided “snapshot” views of organism metabolism at specific stages of growth, generally at exponential growth. This approach has limitations in that metabolic history of the modeled system cannot be studied. The inability to study the complete metabolic history has limited stoichiometric metabolic modeling only to the static investigations of an inherently dynamic process. In this work, we have sought to address this limitation by introducing an optimization-based computational framework and applying to a stoichiometric model of the model plant Arabidopsis thaliana of four linked sub-models of leaf, root, seed, and stem tissues which models the core carbon metabolism through the lifecycle of arabidopsis (named as p-ath780). Uniquely, this framework and model considers diurnal metabolism, changes in tissue mass, carbohydrate storage, and loss of plant mass to senescence and seed dispersal. p-ath780 provide “snapshots” of core-carbon metabolism at one hour intervals of growth, in order to show the evolution of metabolism and whole-plant growth across the lifecycle of a single representative plant. Further, it can simulate important growth stages including seed germination, leaf development, flower production, and silique ripening. The computational framework has shown broad agreement with published experimental data in tissue mass yield, maintenance cost, senescence cost, and whole-plant growth checkpoints. Having focused on core-carbon metabolism, it serves as a scaffold for lifecycle models of other plant systems, to further increase the sophistication of in silico metabolic modeling, and to increase the range of hypotheses which can be investigated in silico. As an example, we have investigated the effect of alternate growth objectives on this plant over the lifecycle.Author SummaryIn an attempt to study the evolution of metabolism across the lifecycle of plants, in this work we have created an optimization-based framework for the in silico modeling of plant metabolism across the lifecycle of a model plant. We then applied this framework to four core-carbon tissue-level (namely, leaf, root, seed, and stem) stoichiometric models of the model plant species Arabidopsis thaliana, and further informed this framework with a wide array of published in vivo data to increase model and framework accuracy. Unique to the p-ath780 model, comparted to other models of plant metabolism, is the simultaneous considerations of diurnal metabolism, carbohydrate storage, changes in tissue mass (including losses), and changes in metabolism with respect to plant growth stage. This provides a more complete picture of plant metabolism and allows for a wider array of future studies of plant metabolism, particularly since we have only modeled the core carbon metabolism of A. thaliana, allowing this work to serve as a framework for studies of other plant systems.



2021 ◽  
Vol 11 ◽  
Author(s):  
Songmei Shi ◽  
Yuling Qiu ◽  
Miao Wen ◽  
Xiao Xu ◽  
Xingshui Dong ◽  
...  

Almost all elevated atmospheric CO2 concentrations (eCO2) studies have not addressed the potential responses of plant growth to different CO2 in daytime and nighttime. The present study was to determine the impact of daytime and/or nighttime eCO2 on growth and quality of mulberry (Morus alba L.), a perennial multipurpose cash plant. Six-month-old mulberry seedlings were hence grown in environmentally auto-controlled growth chambers under four CO2 concentrations: (1) ambient CO2 (ACO2, 410 μmol mol–1 daytime/460 μmol mol–1 nighttime), (2) sole daytime elevated CO2 (DeCO2, 710 μmol mol–1/460 μmol mol–1), (3) sole nighttime elevated CO2 (NeCO2, 410 μmol mol–1/760 μmol mol–1), and (4) continuous daytime and nighttime elevated CO2 (D + NeCO2, 710 μmol mol–1/760 μmol mol–1). Plant growth characteristics, nutrient uptake, and leaf quality were then examined after 120 days of CO2 exposure. Compared to control, DeCO2 and (D + N)eCO2 increased plant biomass production and thus the harvest of nutrients and accumulation of leaf carbohydrates (starch, soluble sugar, and fatty acid) and N-containing compounds (free amino acid and protein), though there were some decreases in the concentration of leaf N, P, Mg, Fe, and Zn. NeCO2 had no significant effects on leaf yield but an extent positive effect on leaf nutritional quality due to their concentration increase in leaf B, Cu, starch, and soluble sugar. Meanwhile, (D + N)eCO2 decreased mulberry leaf yield and harvest of nutritious compounds for silkworm when compared with DeCO2. The reason may be associated to N, P, Mg, Fe, and Zn that are closely related to leaf pigment and N metabolism. Therefore, the rational application of mineral nutrient (especially N, P, Fe, Mg, and Zn) fertilizers is important for a sustainable mulberry production under future atmosphere CO2 concentrations.



Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1831
Author(s):  
Maria L. Pappas ◽  
Konstantinos Samaras ◽  
Ioannis Koufakis ◽  
George D. Broufas

Beneficial soil microbes have long been recognized for their ability to improve plant growth, to antagonize pathogens and to prime plants against biotic stressors. Nevertheless, their ability to enhance plant resistance against arthropod pests remains largely unexplored, especially in crop plants such as pepper. Herein, we assessed the effects of several fungal and bacterial species/strains applied in the soil on the performance of key pests of pepper plants. Specifically, we recorded the impact of pepper inoculation with commercial strains of beneficial bacteria (Bacillus amyloliquefaciens and Pseudomonas spp.) as well as fungi (Trichoderma spp. and Cordyceps fumosorosea) on the population growth of the green peach aphid, Myzus persicae, and the two-spotted spider mite, Tetranychus urticae. Furthermore, we recorded the effects of microbial inoculation on plant growth parameters, such as stem and root weight. We found that both pests can be negatively affected by microbial inoculation: spider mites laid up to 40% fewer eggs, and the number of aphids were up to 50% less on pepper-inoculated plants, depending on the microbe. We also recorded a variation among the tested microbes in their impact on herbivore performance, but no significant effects were found on plant biomass. Our results add to the growing literature that beneficial soil microbes may be capable of exerting biocontrol capabilities against aboveground herbivorous pests possibly, among other means, via the elicitation of plant defense responses.



Author(s):  
Shelby M. Gruss ◽  
Manoj Ghaste ◽  
Joshua R. Widhalm ◽  
Mitchell R. Tuinstra

AbstractCyanogenic glucosides (CGs) play a key role in host-plant defense to insect feeding; however, the metabolic tradeoffs between synthesis of CGs and plant growth are not well understood. In this study, genetic mutants coupled with nondestructive phenotyping techniques were used to study the impact of the CG dhurrin on fall armyworm [Spodoptera frugiperda (J.E. Smith)] (FAW) feeding and plant growth in sorghum [Sorghum bicolor (L.) Moench]. A genetic mutation in CYP79A1 gene that disrupts dhurrin biosynthesis was used to develop sets of near-isogenic lines (NILs) with contrasting dhurrin contents in the Tx623 bmr6 genetic background. The NILs were evaluated for differences in plant growth and FAW feeding damage in replicated greenhouse and field trials. Greenhouse studies showed that dhurrin-free Tx623 bmr6 cyp79a1 plants grew more quickly than wild-type plants but were more susceptible to insect feeding based on changes in green plant area (GPA), total leaf area, and total dry weight over time. The NILs exhibited similar patterns of growth in field trials with significant differences in leaf area and dry weight of dhurrin-free plants between the infested and non-infested treatments. Taken together, these studies reveal a significant metabolic tradeoff between CG biosynthesis and plant growth in sorghum seedlings. Disruption of dhurrin biosynthesis produces plants with higher growth rates than wild-type plants but these plants have greater susceptibility to FAW feeding.



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