scholarly journals An Allelopathic Role for Garlic Root Exudates in the Regulation of Carbohydrate Metabolism in Cucumber in a Hydroponic Co-Culture System

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 45 ◽  
Author(s):  
Haiyan Ding ◽  
Ahmad Ali ◽  
Zhihui Cheng

Garlic is considered to have a strong positive effect on the growth and yield of receptors under soil cultivation conditions. However, how this positive promotion is produced by changing the growth environment of the receptors or directly acting on the receptors is still not very clear. The direct influence of co-culturing with different quantities of garlic plants (the control 5, 10, 15, 20) on the growth and biochemical processes of cucumber plants was studied using a hydroponic co-culture system. Different numbers of garlic bulbs inhibited the growth of cucumber plants and increased the production and induction of reactive oxygen species, which accompanied the enhancement of lipid peroxidation and oxidative damage to cucumber. This allelopathic exposure further reduced the chlorophyll contents and photosynthesis rate, and consequently impaired the photosynthetic performance of photosystem II (PSII). Garlic root exudates increased the leaves’ carbohydrates accumulation, such as soluble sugar contents and sucrose levels by regulating the activities of metabolismic enzymes; however, no such accumulation was observed in the roots. Our results suggested that garlic root exudates can mediate negative plant–plant interactions and its phytotoxic influence on cucumber plants may have occurred through the application of oxidative stress, which consequently imbalanced the source-to-sink photo-assimilate flow.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lawan Gana Ali ◽  
Rosimah Nulit ◽  
Mohd Hafiz Ibrahim ◽  
Christina Yong Seok Yien

AbstractRice is an important staple crop produced and consumed worldwide. However, poor seed emergence is one of the main impediments to obtaining higher yield of rice especially in hot and dry ecosystems of the world that are ravaged by drought. Therefore, this study was carried out to evaluate the effects of potassium nitrate (KNO3), salicylic acid (SA) and silicon dioxide (SiO2) priming in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44 rice under drought conditions. Rice seedlings primed with 2.5% and 5% KNO3, 3% and 3.5% SiO2, and 1 mM and 2.5 mM SA were subjected to three drought levels of low, moderate and severe under the greenhouse. Seed emergence, seedling growth, biochemical attributes and antioxidant activities were thereafter evaluated. Seed priming experiments were laid in a completely randomized design with five replicates per treatment. The results found that rice seedlings responded differently to different priming treatments. However, all primed rice seedlings had significantly (P ≤ 0.05) improved emergence percentage (72–92%), seedling growth, seedling vigor, seedling fresh and dry biomass and shorter emergence time compared with controls. Likewise, total soluble protein content, activities of catalase, ascorbate peroxidase and superoxide dismutase, carbohydrate, soluble sugar and total chlorophyll contents of rice seedlings were increased by more than two-folds by seed priming compared with control. Salicylic acid showed less effect in increasing emergence, seedling growth, antioxidant activities and biochemical attributes of rice. Thus, this study established that seed priming with KNO3 (2.5% and 5%) and SiO2 (3% and 3.5%) were more effective in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44. Thus, priming of FARO44 rice with this chemical is recommended for fast emergence, seedling growth and drought resistance in dry ecosystems.


2020 ◽  
Author(s):  
Ezekiel Taiwo Afolayan

AbstractThis work compares the physiological and yield characteristics of white yam (Dioscorea rotundata – Poir) under Arbuscular mycorrhizal fungi (AMF) inoculation, green manures of Gliricidia sepium, Leucaena leucocephala and other soil amendments. The experiment was conducted on the plot of land that had been overcropped, located at the back of the male Hostel, Federal College of Education, Abeokuta, Ogun State, Nigeria. The land was cleared and heaped at 1m x 1m apart. The experimental design employed was a complete randomized design in 5 replicates. The treatments were Glomus deserticola (GD), Glomus fasciculatum (GF), Gliricidia sepium (GS), Leucaena leucocephala (LL), Poultry manure (PM) and NPK fertilizers. Soils were dug from the heaps, 20 g of the inoculums of AMF (GD/ GF) were poured into the dug hole, seeds were laid on it and covered with soil (for GD & GF treatments). Others were applied at one week after sprouting. Growth and yield Parameters were determined at harvest while relative water and chlorophyll contents were measured forth nightly from 10 weeks after treatment. Data obtained were subjected to ANOVA while means were separated by Duncan multiple range test at P> 0.05. Results showed that growth, yield and physiological characters were enhanced in GD, GD+GF, GS and PM treated plants more than in inorganic fertilizers treated plants. There was a positive significant relationship between white yam’s growth, physiology and tuber yield. The study justifies the use of plant/animal manures and Arbuscular mycorrhizal fungi in place of inorganic fertilizers.


Beverages ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 90 ◽  
Author(s):  
José Casanova-Gascón ◽  
Pablo Martín-Ramos ◽  
Clara Martí-Dalmau ◽  
David Badía-Villas

Lime-induced chlorosis (LIC) is an important abiotic constraint affecting the growth and yield of grapevines growing in calcareous soils in the Mediterranean region, and the sensory properties of the produced wine. In the work presented herein, the impact of LIC on the nutritional status and chlorophyll content was assessed for eleven varieties and a clone (Merlot, Pinot Noir, Cabernet Sauvignon, Tempranillo, Parraleta, Moristel, Aglianico, Macabeo, Sauvignon, Chardonnay, and Riesling), grafted to the same rootstock (1103 Paulsen). Macro- and micronutrient contents were determined in the fruit set and veraison stages by petiole analyses, while chlorophyll content in young leaves was monitored by SPAD. Significant differences were detected amongst varieties for all nutrients (including Fe), and inverse relationships between Fe and P contents in the petiole and chlorophyll concentration in the young leaves were found. Regarding LIC resistance, the Fe and chlorophyll contents suggest that Cabernet Sauvignon, Tempranillo and Aglianico varieties would show the best performance, while Sauvignon would be the least tolerant.


2008 ◽  
Vol 1 (1) ◽  
pp. 128-137 ◽  
Author(s):  
Cheruth Abdul Jaleel ◽  
Zhao Changxing ◽  
K Jayakumar ◽  
M Iqbal

A pot culture experiment has been carried out to find the extent of changes occurring in the biochemicals and nutrients of maize plants (Zea mays L.) grown under different concentrations of cobalt (50, 100, 150, 200, 250 mg kg-1 soil). The growth and yield parameters such as seedling vigour, number of cobs, number of seeds per plant; photosynthetic pigments viz., chlorophyll ‘a’, chlorophyll ‘b’, and total chlorophyll contents; biochemicals like total sugars (reducing and non reducing), starch, amino acids and protein content and various macro- and micronutrients are determined 90 days after sowing (DAS). All the growth parameters, pigment content, biochemicals and mineral content increase at 50 mg Co kg-1 soil when compared with the control. Further increase in the Co levels (100-200 mg kg-1 soil) has a negative effect on all the above parameters.   Keywords: Cobalt; Growth; Zea mays; Biochemicals; Nutrients. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  DOI: 10.3329/jsr.v1i1.1226 


Agronomy ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 266 ◽  
Author(s):  
Shumaila Khan ◽  
Hongjun Yu ◽  
Qiang Li ◽  
Yinan Gao ◽  
Basheer Noman Sallam ◽  
...  

As natural plant growth stimulators, amino acids are widely used to improve the yield and quality of crops. Several studies have illustrated the effects of different amino acids on lettuce plant parts. However, the effects of applying single amino acids on root growth remain elusive. The objective of this study was to evaluate the effect of root application of L-methionine on the growth of lettuce. In this study, two successive experiments on butterhead lettuce were conducted under hydroponic conditions. Three amino acids, L-methionine (20 mg/L), L-glycine (210 mg/L), and L-tryptophan (220 mg/L), were applied separately. L-methionine significantly increased the growth performance by 23.60%, whereas growth using L-tryptophan and L-glycine decreased by 98.78% and 27.45%, respectively. Considering the results of the first experiment, a second experiment was established with different concentrations of L-methionine (2200 mg/L, 220 mg/L, 22 mg/L, 2.2 mg/L, 0.2 mg/L, and 0.02 mg/L). The plants were allowed to grow for four weeks. Leaf width, plant area, leaf area, chlorophyll contents, etc., were evaluated. The results show that plant growth significantly improved by applying L-methionine at the lowest concentrations of 0.2 mg/L and 0.02 mg/L, which can, therefore, improve hydroponic production of lettuce and, accordingly, human nutrition.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2828
Author(s):  
Md. Shakhawat Hossain ◽  
Jing Li ◽  
Ashim Sikdar ◽  
Mirza Hasanuzzaman ◽  
Ferdinand Uzizerimana ◽  
...  

Tartary buckwheat is one of the nutritious minor cereals and is grown in high-cold mountainous areas of arid and semi-arid zones where drought is a common phenomenon, potentially reducing the growth and yield. Melatonin, which is an amphiphilic low molecular weight compound, has been proven to exert significant effects in plants, under abiotic stresses, but its role in the Tartary buckwheat under drought stress remains unexplored. We evaluated the influence of melatonin supplementation on plant morphology and different physiological activities, to enhance tolerance to posed drought stress by scavenging reactive oxygen species (ROS) and alleviating lipid peroxidation. Drought stress decreased the plant growth and biomass production compared to the control. Drought also decreased Chl a, b, and the Fv/Fm ratio by 54%, 70%, and 8%, respectively, which was associated with the disorganized stomatal properties. Under drought stress, H2O2, O2•−, and malondialdehyde (MDA) contents increased by 2.30, 2.43, and 2.22-folds, respectively, which caused oxidative stress. In contrast, proline and soluble sugar content were increased by 84% and 39%, respectively. However, exogenous melatonin (100 µM) could improve plant growth by preventing ROS-induced oxidative damage by increasing photosynthesis, enzymatic antioxidants (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase), secondary metabolites like phenylalanine ammonialyase, phenolics, and flavonoids, total antioxidant scavenging (free radical DPPH scavenging), and maintaining relative water content and osmoregulation substances under water stress. Therefore, our study suggested that exogenous melatonin could accelerate drought resistance by enhancing photosynthesis and antioxidant defense in Tartary buckwheat plants.


1985 ◽  
Vol 63 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
David H. Turpin ◽  
David B. Layzell

A chemostat culture system is described in which measurements of rates associated with carbon and nitrogen assimilation may be made in in situ steady-state cultures of N2-fixing cyanobacteria. Net C and N assimilations were determined from the steady-state cellular carbon and nitrogen contents and the steady-state growth rate of the cultures. O2 evolution in the light and short-term 14C assimilation were measured simultaneously in unperturbed culture cuvettes. 14C assimilation was linear with time through the origin over the 20-min sampling period, thereby providing a measure of gross photosynthesis. C2H2 reduction was measured within the culture cuvette using an open gas analysis system. Steady-state rates of C2H2 reduction were obtained within 10 min and remained constant for up to 1 h. Preliminary results showed that at similar growth rates (0.018–0.019 h−1) cultures grown on [Formula: see text] and N2 contained heterocysts, were smaller, and had higher chlorophyll contents than cells grown on NH3. Corresponding gross photosynthesis was 1.6 to 1.8 times higher than net photosynthesis in [Formula: see text] and N2-grown cells; however, for NH3-grown cells the ratio of gross photosynthesis:net photosynthesis was close to unity. These results are discussed with reference to the energetic costs associated with N assimilation in cyanobacteria.


1986 ◽  
Vol 32 (4) ◽  
pp. 348-352
Author(s):  
Keuk-Ki Lee ◽  
Robert C. Shearman ◽  
Robert V. Klucas

Response of 'Park' Kentucky bluegrass to inoculation with Klebsiella pneumoniae strain W-6 was tested under field conditions. Field inoculation did not increase nitrogenase activity measured in situ, but did increase the nitrogenase activity as measured using an excised root assay which included a 10-h incubation before the addition of acetylene. Fifteen lines composing 'Park' were grown in fritted-clay medium, inoculated with soil, and compared for nitrogenase activities using the excised roots assay. Significant differences were observed between two lines. Six lines were selected from the 15 lines, grown hydroponically, inoculated with soil, and assayed for nitrogenase activity using intact 105-day-old plants. Nitrogenase activities were immediately detectable and increased curvilinearly. Differences in nitrogenase activities among the six lines were detected within 1 h and significant differences were evident in 4 h. The six selected lines were also tested for levels of anthrone-reactive sugars in roots and root exudates of hydroponically grown plants. Significant differences were detected in levels of sugars in roots but not in root exudates. Possible correlations were sought among and within the three different experiments involving the six selected lines. With hydroponically grown plants, nitrogenase activities during the first 4 h were highly correlated with those after 24 h incubation. Correlations were found between nitrogenase activities in excised roots and soluble sugar concentrations in root tissue and root exudates.


2020 ◽  
Author(s):  
Guozhang Bao ◽  
Wenyi Tang ◽  
Qirui An ◽  
Yaoxin Liu ◽  
Jiaqi Tian ◽  
...  

Abstract BackgroundIn the early spring of northern China, the combined stresses of freeze-thaw, deicing salt and acid deposition are the main ecological threats to the urban turf ecosystem. ResultsWe studied changes in the Malondialdehyde (MDA), protein, soluble sugar, proline and chlorophyll contents of DongMu No. 1seedlings of 8 treatment combination groups which are imposed by freeze-thaw (F), acid rain (A) and deicing salt (D). An increasing in MDA content showed that the membrane system of seedlings was damaged under combined stress (F+A+D). The changes indicated that under the adverse conditions, the proline and soluble sugar contents increased obviously with the accumulation of MDA in the plants, while the chlorophyll content decreased significantly.ConclusionPlants can alleviate the damage caused by stress by increasing soluble sugars and by regulating the proline content to maintain osmotic balance.


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