scholarly journals EFFECTS OF CONTINUOUS LIGHTING ON ENZYME ACTIVITIES OF LEAF CARBON METABOLISM OF TOMATO AND PEPPER PLANTS

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 250a-250 ◽  
Author(s):  
Dominique-André Demers ◽  
Serge Yelle ◽  
André Gosselin

Exposure of tomato and pepper plants to long photoperiods (20 hours or more for tomato; 24 hours for pepper) results in leaf chlorosis (tomato), leaf deformities (pepper), and decreased growth and productivity (both species). Some researchers have suggested that excessive starch accumulation in the leaves could be the cause of the negative effects. We observed that tomato and pepper plants do accumulate more starch in their leaves when grown under a long photoperiod (24 hours) compared to a shorter one (16 hours). However, our results indicated that these accumulations were not caused by a limited sink strength but by an alteration of the carbon metabolism at the leaf level. In our last experiment, we studied the activity of enzymes [sucrose phosphate synthase (SPS), sucrose synthase (SS), invertase] of leaf carbon metabolism in tomato and pepper plants grown under different photoperiods (natural, natural + supplemental light of 100 μmol·m-2·s-1 during 16 and 24 hours). We observed a 10% to 15% decrease in leaf SPS activity in tomato (not in pepper) plants grown under a 24-hour photoperiod. In both species, invertase and SS activities were not affected by photoperiod treatments. In tomato plants grown under a 24-hour photoperiod, the decrease in SPS activity corresponded to the appearance of leaf chlorosis (6 to 7 weeks after the beginning of treatments). Therefore, it appears that leaf carbon metabolism could be involved in the development of negative effects of long photoperiod in tomato plants, but not in pepper plants. The fact that photoperiod had no apparent effect on leaf carbon metabolism of pepper may explain why this species can tolerate longer photoperiods than tomato plants.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Tadeja Savi ◽  
Almudena García González ◽  
Jose Carlos Herrera ◽  
Astrid Forneck

Abstract Background Intensity of drought stress and pest attacks is forecasted to increase in the near future posing a serious threat to natural and agricultural ecosystems. Knowledge on potential effects of a combined abiotic-biotic stress on whole-plant physiology is lacking. We monitored the water status and carbon metabolism of a vine rootstock with or without scion subjected to water shortening and/or infestation with the sucking insect phylloxera (Daktulosphaira vitifoliae Fitch). We measured non-structural carbohydrates and biomass of different plant organs to assess the stress-induced responses at the root, stem, and leaf level. Effects of watering on root infestation were also addressed. Results Higher root infestation was observed in drought-stressed plants compared to well-watered. The drought had a significant impact on most of the measured functional traits. Phylloxera further influenced vines water and carbon metabolism and enforced the sink strength of the roots by stimulating photosynthates translocation. The insect induced carbon depletion, reprogramed vine development, while preventing biomass compensation. A synergic effect of biotic-abiotic stress could be detected in several physiological and morphological traits. Conclusions Our results indicate that events of water shortage favour insects’ feeding damage and increase the abundance of root nodosities. Root phylloxera infestation imposes a considerable stress to the plants which might exacerbate the negative effects of drought.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 778E-778
Author(s):  
Dominique-André Demers ◽  
Sylvain Dubé ◽  
Serge Yelle ◽  
André Gosselin

Growing tomato and pepper plants under continuous light causes negative effects such as leaf chlorosis and deformities, and decreased growth and yield. Such effects are more pronounced on tomato plants. Our general objectives are to identify the physiological process(es) responsible for these negative effects and to explain the difference in sensitivity of tomato and pepper plants to continuous light. The specific objective of this experiment was to determine the effects of continuous light and light spectral composition on photosynthesis and related processes of tomato and pepper plants. Tomato and pepper plants were place on 7 June 1994 in growth chambers under photoperiod treatments of 12 h [high-pressure sodium (HPS) lamps], 24 h (HPS lamps), and 24 h [metal halide (MH) lamps]. For all treatments, FPP was 350 μmol·m–2·s–1, temperatures were 21C (day) and 17C (night), and RH was 70%. Every 2 weeks (7 June until 2 Aug.), tomato and pepper leaf samples were harvested and frozen in liquid nitrogen for subsequent measurements of starch content (Robinson et al, 1988, Plant Physiol.), sucrose phosphate synthase activities (Dali et al., 1992, Plant Physiol.) and chlorophyll and carotenoid content (determination on HPLC). A system that measured gas exchange and chlorophyll fluorescence of fresh leaf samples was used to determine the photosynthetic rate and quantum yield of CO2 fixation and electron transport. Development of the negative effects of continuous light on plants was monitored. Light spectral composition of the two types of lamps was measured using a spectroradiometer. Results show that, under continuous light, pepper plants were less-efficient than tomato plants in using light for CO2 fixation, but were more efficient in dissipating the extra energy received. This may explain why pepper plants are less sensitive to continuous light than tomato plants. MH lamps caused more-severe chloroses on tomato leaves than HPS plants. We believe that the higher proportion of UV-light provided by MH lamps may be related to this effect. Detailed results will be presented.


Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 546-551 ◽  
Author(s):  
Judy A. Gougler ◽  
Donald R. Geiger

Glyphosate [N-(phosphonomethyl)glycine] had several effects on carbon translocation in sugarbeet (Beta vulgarisL. ‘Klein E multigerm’): a) import of carbon by sink leaves was inhibited, b) net starch accumulation in source leaves was stopped, and c) carbon export from source leaves in the dark was stopped following 10 h of treatment in the light. During periods when no carbon was exported, glyphosate also was not transported from treated leaves. The limitation of glyphosate transport, resulting from disruption of carbon metabolism, appears important in the study and use of the herbicide.


2022 ◽  
Vol 12 ◽  
Author(s):  
Maria Cristina Della Lucia ◽  
Ali Baghdadi ◽  
Francesca Mangione ◽  
Matteo Borella ◽  
Walter Zegada-Lizarazu ◽  
...  

This work aimed to study the effects in tomato (Solanum lycopersicum L.) of foliar applications of a novel calcium-based biostimulant (SOB01) using an omics approach involving transcriptomics and physiological profiling. A calcium-chloride fertilizer (SOB02) was used as a product reference standard. Plants were grown under well-watered (WW) and water stress (WS) conditions in a growth chamber. We firstly compared the transcriptome profile of treated and untreated tomato plants using the software RStudio. Totally, 968 and 1,657 differentially expressed genes (DEGs) (adj-p-value < 0.1 and |log2(fold change)| ≥ 1) were identified after SOB01 and SOB02 leaf treatments, respectively. Expression patterns of 9 DEGs involved in nutrient metabolism and osmotic stress tolerance were validated by real-time quantitative reverse transcription PCR (RT-qPCR) analysis. Principal component analysis (PCA) on RT-qPCR results highlighted that the gene expression profiles after SOB01 treatment in different water regimes were clustering together, suggesting that the expression pattern of the analyzed genes in well water and water stress plants was similar in the presence of SOB01 treatment. Physiological analyses demonstrated that the biostimulant application increased the photosynthetic rate and the chlorophyll content under water deficiency compared to the standard fertilizer and led to a higher yield in terms of fruit dry matter and a reduction in the number of cracked fruits. In conclusion, transcriptome and physiological profiling provided comprehensive information on the biostimulant effects highlighting that SOB01 applications improved the ability of the tomato plants to mitigate the negative effects of water stress.


EUGENIA ◽  
2019 ◽  
Vol 25 (1) ◽  
Author(s):  
Yoakhim Y. E Oessoe

This research aims to study 1) Maternal effect on the inheritance of yield components of Manado Yellow Use of Insecticides is one way that is very often made vegetable farmersto cope with pest and plant diseases. However, the use of insecticides may give negative effects for consumers of food containing residues of these poisons.Methodology of research is survey and laboratory. Collecting data in the survey was an interview of 20 vegetable farmers, each 10 from Modoinding and 10 from Rurukan that determined purposively. Laboratory data obtainedwith the ways to identify residues in the cabbage and tomatoes from Modoinding and Rurukan , using Gas Chromatography (GC) according to the analysis method of Pusat Pengujian Obat dan Makanan.Vegetable farmers in Modoinding and Rurukan often apply the insecticide organophospate and pyretroid on cabbage and tomato plants. The residues level in ccabbage and tomato from Modoinding and Rurukan far exceed the value of Acceptable Daily Intake of profonefos allowed.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1488
Author(s):  
Artemii P. Gorshkov ◽  
Anna V. Tsyganova ◽  
Maxim G. Vorobiev ◽  
Viktor E. Tsyganov

In Russia, tetramethylthiuram disulfide (TMTD) is a fungicide widely used in the cultivation of legumes, including the pea (Pisum sativum). Application of TMTD can negatively affect nodulation; nevertheless, its effect on the histological and ultrastructural organization of nodules has not previously been investigated. In this study, the effect of TMTD at three concentrations (0.4, 4, and 8 g/kg) on nodule development in three pea genotypes (laboratory lines Sprint-2 and SGE, and cultivar ‘Finale’) was examined. In SGE, TMTD at 0.4 g/kg reduced the nodule number and shoot and root fresh weights. Treatment with TMTD at 8 g/kg changed the nodule color from pink to green, indicative of nodule senescence. Light and transmission electron microscopy analyses revealed negative effects of TMTD on nodule structure in each genotype. ‘Finale’ was the most sensitive cultivar to TMTD and Sprint-2 was the most tolerant. The negative effects of TMTD on nodules included the appearance of a senescence zone, starch accumulation, swelling of cell walls accompanied by a loss of electron density, thickening of the infection thread walls, symbiosome fusion, and bacteroid degradation. These results demonstrate how TMTD adversely affects nodules in the pea and will be useful for developing strategies to optimize fungicide use on legume crops.


2020 ◽  
Vol 17 ◽  
pp. 00231
Author(s):  
F. Yasar ◽  
O. Uzal

The present study was carried out in a climate chamber and water culture of physiology laboratory of Van Yüzüncü Yıl University, Faculty of Agriculture, Department of Horticulture. Demre pepper varieties are used in the study of different levels of calcium (Ca) morphological and biochemical effects of pepper plants under salt stress were investigated. The study was carried out in 16/8 hour light / dark photoperiod, 25 oC and % 70 humid climate chamber in controlled conditions. In order to determine the biochemical changes occurring in stressed plants, the amount of ions Na, K, Ca, Cl in root, stem and leaves of plants and Ca/Na ratio were determined. The accumulation of Na and Cl ions was found to decrease in root, stem and leaves as the dose of Ca increased. It can be said that increasing doses of Ca applications under salt stress are partially effective in reducing the negative effects of salt.


2004 ◽  
Vol 47 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Seok-Yoon Yoon ◽  
Jang-Wook Lee ◽  
Seong-Hee Bhoo ◽  
Jong-Seong Jeon ◽  
Youn-Hyung Lee ◽  
...  

1985 ◽  
Vol 65 (1) ◽  
pp. 185-192 ◽  
Author(s):  
ANDRÉ GOSSELIN ◽  
MARC-J. TRUDEL

Six-week-old tomato plants (Lycopersicon esculentum Mill. ’Vendor’) were maintained at five root temperatures (12, 18, 24, 30 or 36 °C) and five night air temperatures (8, 12, 16, 20 or 24 °C) for a period of 4 wk. Increase in root temperature partly offset the negative effects of low night air temperature on leaf dry weight and leaf area. Our results showed that higher root temperatures (30 °C) are required at low night air temperature (8 °C) for optimum plant growth. Lower rates of plant photosynthesis at low root and/or night air temperatures resulted mainly from reduced leaf growth and expansion, but also from a decrease in the photosynthetic capacity of the leaves. Our results suggest combining split-night temperature and soil warming techniques to improve the productivity of tomato plants and to reduce greenhouse heating costs.Key words: Tomato substrate, temperature, photosynthesis, growth


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