scholarly journals Overproduction of ABA in rootstocks alleviates salinity stress in tomato shoots

Author(s):  
Cristina Martínez Andújar ◽  
Ascensión Martínez-Pérez ◽  
Alfonso Albacete Moreno ◽  
Purificación A Martínez-Melgarejo ◽  
Ian Dodd ◽  
...  

To determine whether root-supplied ABA alleviates saline stress, tomato (Solanum lycopersicum L. cv. Sugar Drop) was grafted onto two independent lines overexpressing the SlNCED1 (9-cis-epoxycarotenoid dioxygenase) gene (NCED OE) and wild type rootstocks. After 200 days of salinity irrigation (EC = 3.5 dS m-1), plants with NCED OE rootstocks had 30% higher fruit yield, but root biomass and lateral root development was reduced. Although NCED OE rootstocks upregulated ABA-signalling (AREB, ATHB12), ethylene-related (ACCs, ERFs), aquaporin (PIPs) and stress-related (TAS14, KIN, LEA) genes, downregulation of PYL ABA receptors and signalling components (WRKYs), ethylene synthesis (ACOs) and auxin responsive factors occurred. Elevated SlNCED1 expression enhanced ABA levels in reproductive tissue while ABA catabolites accumulated in leaf and xylem sap suggesting homeostatic mechanisms. NCED OE also reduced xylem cytokinin transport to the shoot and stimulated foliar 2-isopentenyl adenine (iP) accumulation and phloem transport. Moreover, increased xylem gibberellin GA3 levels in growing fruit trusses was associated with enhanced reproductive growth. Improved photosynthesis without changes in stomatal conductance was consistent with hormone-mediated alteration of leaf growth and mesophyll structure, which combined with lower assimilate requirement in the roots and systemic changes in hormone balances could explain enhanced vigour, reproductive growth and yield under saline stress.

2016 ◽  
Vol 67 (18) ◽  
pp. 5301-5311 ◽  
Author(s):  
Andreas D Peuke

Abstract In a series of experiments with Ricinus communis, abscisic acid (ABA) concentrations in tissues and transport saps, its de novo biosynthesis, long-distance transport, and metabolism (degradation) were affected by nutritional conditions, nitrogen (N) source, and nutrient limitation, or salt stress. In the present study these data were statistically re-evaluated, and new correlations presented that underpin the importance of this universal phytohormone. The biggest differences in ABA concentration were observed in xylem sap. N source had the strongest effect; however, nutrient limitation (particularly phosphorus limitation) and salt also had significant effects. ABA was found in greater concentration in phloem sap compared with xylem sap; however, the effect of treatment on ABA concentration in phloem was lower. In the leaves, ABA concentration was most variable compared with the other tissues. This variation was only affected by the N source. In roots, ABA was significantly decreased by nutrient limitation. Of the compartments in which ABA was quantified, xylem sap ABA concentration was most significantly correlated with leaf stomatal conductance and leaf growth. Additionally, ABA concentration in xylem was significantly correlated to that in phloem, indicating a 6-fold concentration increase from xylem to phloem. The ABA flow model showed that biosynthesis of ABA in roots affected the xylem flow of ABA. Moreover, ABA concentration in xylem affected the degradation of the phytohormone in shoots and also its export from shoots via phloem. The role of phloem transport is discussed since it stimulates ABA metabolism in roots.


2020 ◽  
Vol 51 (4) ◽  
pp. 1001-1014
Author(s):  
Sulaiman & Sadiq

The experiment was conducted in a greenhouse during 2017 and 2018 growing seasons to evaluate the impact of the shading and various nutrition programs on mitigating heat stress, reducing the use of chemical minerals, improving the reproductive growth and yield of tomato plant. Split-plot within Randomized Complete Block Design (RCBD) with three replications was conducted in this study. Shading factor was allocated in the main plots and the nutrition programs distributed randomly in the subplots. Results indicate that shading resulted in the decrease of daytime temperature by 5.7˚C as an average for both seasons; thus a significant increasing was found in leaf contents of macro nutrients (Nitrogen, Phosphorous, and Potassium), and micro nutrients (Iron, Zinc and Boron), except the Iron content in 2018 growing season. Furthermore, shading improved significantly the reproductive growth and tomato yield. Among the plant nutrition programs, the integrated nutrient management (INM) including the application of organic substances, bio inoculum of AMF and 50% of the recommended dose of chemical fertilizers; lead to the enhancement of nutrients content, reproductive characteristics and plant yield. Generally, combination of both shading and INM showed positive effects on plants nutrient status and persisting balance on tomato flowering growth and fruits yield.


2017 ◽  
Vol 9 (2) ◽  
pp. 1170-1175 ◽  
Author(s):  
Ankush Ankush ◽  
Vikram Singh ◽  
S. K. Sharma

Drip irrigation technique has proved its superiority over other methods of irrigation due to direct application of water and nutrient in the vicinity of root zone. A field study was conducted to evaluate the effect of irrigation and fertigation scheduling through drip irrigation in tomato (Solanum lycopersicum L.) during Rabi season of 2015-16 at Rajasthan College of Agriculture, MPUAT, Udaipur. There were three irrigation levels and five fertilization levels in split-plot design with three replications. Nutrient content in plant and fruit was found higher under the application of drip irrigation at 100 % PE (I1) and at 100 % RDF through fertigation (F1). Maximum nutrient uptake by tomato i.e. nitrogen (166.83 kg ha-1), phosphorus (41.59 kg ha-1) and potassium (183.08 kg ha-1) was recorded with treatment combination of drip irrigation at 75 % PE (I2) + 75 % RDF through fertigation + 2 foliar spray of 1 % urea phosphate (F3). Similarly, significantly maximum yield and growth attributes i.e. fruit yield (201.25 q ha-1), plant height (67.43 cm) and number of branches (12.33) were registered with treatment combination of drip irrigation at 75 % PE and 75 % RDF through fertigation + 2 foliar spray of 1 % urea phosphate. Drip fertigation method has proved to be very significant in improving nutrient uptake which finally resulting in enhancement of growth and yield of tomato crop.


2021 ◽  
Vol 27 (1) ◽  
pp. 20-25
Author(s):  
Ziyad Khalf Salih ◽  
Seyedeh Somayyeh Shafiei Masouleh ◽  
Mohamed Abdulla Ahmed ◽  
Marwan Abdulla Sanam

Abstract Jasmine (Jasminum sambac L.) is an evergreen shrub and very fragrant, which has a very importance in the perfume industry and its flowers are used in different religious and ceremonies. Training the shrubs for more yields of flowers and essential oil with horticultural improvement effects of pruning and amino acids may help gardeners to achieve more benefits. This study aimed to investigate the effects of pruning intensity (without pruning, 40, 60 or 75 cm above ground level) and foliar application of amino acids (without amino acids, tryptophan or glycine) on jasmine shrubs for promoting growth and reproductive growth and the content of essential oil. The results showed that plants with light pruning (75 cm) and foliar application of amino acids especially glycine had the best growth and yield, which means that plants were affected by the interactions of pruning level and application of amino acids.


Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 175 ◽  
Author(s):  
Hipólito Hernández-Hernández ◽  
Antonio Juárez-Maldonado ◽  
Adalberto Benavides-Mendoza ◽  
Hortensia Ortega-Ortiz ◽  
Gregorio Cadenas-Pliego ◽  
...  

Saline stress severely affects the growth and productivity of plants. The activation of hormonal signaling cascades and reactive oxygen species (ROS) in response to salt stress are important for cellular detoxification. Jasmonic acid (JA) and the enzyme SOD (superoxide dismutase), are well recognized markers of salt stress in plants. In this study, the application of chitosan-polyvinyl alcohol hydrogels (Cs-PVA) and copper nanoparticles (Cu NPs) on the growth and expression of defense genes in tomato plants under salt stress was evaluated. Our results demonstrate that Cs-PVA and Cs-PVA + Cu NPs enhance plant growth and also promote the expression of JA and SOD genes in tomato (Solanum lycopersicum L.), under salt stress. We propose that Cs-PVA and Cs-PVA + Cu NPs mitigate saline stress through the regulation of oxidative and ionic stress.


2013 ◽  
Vol 40 (5) ◽  
pp. 459 ◽  
Author(s):  
Patrizia Trifilò ◽  
Maria Assunta Lo Gullo ◽  
Fabio Raimondo ◽  
Sebastiano Salleo ◽  
Andrea Nardini

This work reports on experimental evidence for the role of ion-mediated changes of xylem hydraulic conductivity in the functional response of Solanum lycopersicum L. cv. Naomi to moderate salinity levels. Measurements were performed in fully developed 12-week-old plants grown in half-strength Hoagland solution (control, C-plants) or in the same solution added with 35 mM NaCl (NaCl-plants). NaCl-plants produced a significantly less but heavier leaves and fruits but had similar gas-exchange rates as control plants. Moreover, NaCl-plants showed higher vessel multiple fraction (FVM) than control plants. Xylem sap potassium and sodium concentrations were significantly higher in NaCl-plants than in control plants. When stems were perfused with 10 mM NaCl or KCl, the hydraulic conductance of NaCl plants was nearly 1.5 times higher than in control plants. Accordingly, stem hydraulic conductance measured in planta was higher in NaCl- than in control plants. Our data suggest that tomato plants grown under moderate salinity upregulate xylem sap [Na+] and [K+], as well as sensitivity of xylem hydraulics to sap ionic content, thus, increasing water transport capacity.


2004 ◽  
Vol 31 (9) ◽  
pp. 903 ◽  
Author(s):  
Ian C. Dodd ◽  
Chuong Ngo ◽  
Colin G. N. Turnbull ◽  
Christine A. Beveridge

The rms2 and rms4 pea (Pisum sativum L.) branching mutants have higher and lower xylem-cytokinin concentration, respectively, relative to wild type (WT) plants. These genotypes were grown at two levels of nitrogen (N) supply for 18–20 d to determine whether or not xylem-cytokinin concentration (X-CK) or delivery altered the transpiration and leaf growth responses to N deprivation. Xylem sap was collected by pressurising de-topped root systems. As sap-flow rate increased, X-CK declined in WT and rms2, but did not change in rms4. When grown at 5.0 mm N, X-CKs of rms2 and rms4 were 36% higher and 6-fold lower, respectively, than WT at sap-flow rates equivalent to whole-plant transpiration. Photoperiod cytokinin (CK) delivery rates (the product of transpiration and X-CK) decreased more than 6-fold in rms4. Growth of plants at 0.5 mm N had negligible (< 10%) effects on transpiration rates expressed on a leaf area basis in WT and rms4, but decreased transpiration rates of rms2. The low-N treatment decreased leaf expansion by 20–25% and expanding leaflet N concentration by 15%. These changes were similar in all genotypes. At sap-flow rates equivalent to whole-plant transpiration, the low N treatment decreased X-CK in rms2 but had no discernible effect in WT and rms4. Since the low N treatment decreased transpiration of all genotypes, photoperiod CK delivery rates also decreased in all genotypes. The similar leaf growth response of all genotypes to N deprivation despite differences in both absolute and relative X-CKs and deliveries suggests that shoot N status is more important in regulating leaf expansion than xylem-supplied cytokinins. The decreased X-CK and transpiration rate of rms2 following N deprivation suggests that changes in xylem-supplied CKs may modify water use.


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