Factors That Influence the Yield and Viability of Cucumber (Cucumis sativus L) Cotyledon Protoplasts

1990 ◽  
Vol 38 (2) ◽  
pp. 169 ◽  
Author(s):  
AS Kantharajah ◽  
WA Dodd

Protoplasts isolated from cotyledons of aseptically germinated cucumber seedlings were divided into three size classes. The relationships between tissue age, isolation procedure, yield and protoplast size were investigated. During germination and up to an age of 13 days, the percentage of protoplasts in each size class underwent considerable change with a big reduction in percentage of the largest protoplasts in older cotyledons. Protoplast size and yield could also be manipulated by varying the isolation technique. In this context, temperature, incubation time and shaker speed were significant. By selecting tissue of appropriate age and using a carefully selected isolation procedure the percentage of viable cucumber protoplasts with the ability to form a cell wall and divide can be increased considerably.

1989 ◽  
Vol 67 (3) ◽  
pp. 817-821 ◽  
Author(s):  
A. Raymond Miller ◽  
Joseph P. Dalmasso ◽  
Dale W. Kretchman

Variation of cell wall degrading enzyme activities and tissue firmness from the petal senescence to overripe stages of fruit development was studied in greenhouse-grown cucumbers (Cucumis sativus L. cv. Heinz 3534). Cucumbers exhibited a typical sigmoidal growth curve with a short lag phase (0–8 days after pollination) and extended log phase (8–28 days) followed by a stationary phase. Mesocarp firmness decreased between 10 and 20 days after pollination, then increased until 32 days after pollination. This decrease of mesocarp firmness was accompanied by increased activity of cellulase (3.5-fold), polygalacturonase (20-fold), pectin methylesterase (4-fold), and xylanase (9-fold). By contrast, carpel tissue firmness declined from 8–20 days after pollination, and remained low until 32 days after pollination. Only polygalacturonase and xylanase activities exhibited significant increases (5- and 6-fold, respectively) during softening of this tissue. Further, these peaks of enzyme activity in the carpel occurred 10 days before the corresponding peaks in the mesocarp. These data suggest that mesocarp and carpel tissues of cucumber soften by similar, but not identical mechanisms.


2021 ◽  
Vol 23 (1) ◽  
pp. 176
Author(s):  
Lin Chen ◽  
Fenghua Zheng ◽  
Zili Feng ◽  
Yue Li ◽  
Muxuan Ma ◽  
...  

Vacuolar invertase (VI) can irreversibly degrade sucrose into glucose and fructose and involve in plants abiotic-stress-tolerance. Cucumber (Cucumis sativus L.) is susceptible to drought stress, especially during the seedling stage. To date, the involvement of VI in drought tolerance in cucumber seedlings is in urgent need of exploration. In the present study, a cucumber vacuolar invertase gene, CsVI2, was isolated and functionally characterized. The results showed that (1) CsVI2 showed vacuolar invertase activity both in vivo and in vitro; (2) the transcript level of CsVI2, along with VI activity, was significantly induced by drought stress. Moreover, the expression of sucrose synthase 3 (CsSUS3) was increased and that of sucrose phosphate synthase 1 (CsSPS1) was decreased after exposure to drought stress, which was followed by an increase in sucrose synthase activity and a decrease in sucrose phosphate synthase activity; (3) CsVI2-overexpressing transformed cucumber seedlings showed enhanced vacuolar invertase activity and drought tolerance and 4) protein–protein interaction modelling indicated that a cucumber invertase inhibitor, CsINVINH3, can interact with CsVI2. In summary, the results indicate that CsVI2 as an invertase can regulate sucrose metabolism and enhance drought stress in cucumber seedlings.


2014 ◽  
Vol 49 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Józef Buczek ◽  
Ewa Kowalińska ◽  
Krystyna Kuczera

Investigations were conducted on the influence of tungsten (Na<sub>2</sub>WO<sub>4</sub>) and meta-vanadate (NaVO<sub>3</sub>) on uptake and reduction of nitrates by cucumber seedlings. Tungsten and vanadium almost completely inhibited nitrate reductase activity (NR) after treating the plants for 24 hours with nitrates in the presence of 10<sup>-4</sup> M WO<sub>4</sub><sup>-2</sup> and 10<sup>-3</sup> M VO<sub>3</sub><sup>-</sup>. Uptake of NO<sub>3</sub><sup>-</sup> in the presence of WO<sub>4</sub><sup>-2</sup> in this same period of time was lowered by about 50 %, while in the presence of VO<sub>3</sub><sup>-</sup> by seventy percent. The ratio of NO<sub>3</sub><sup>-</sup> absorbed to that reducted in control plants was around 3, whereas in the presence of WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> 9 and 8 respectively. The effect of NR inhibiting activity by WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> was significant but somewhat weaker if both inhibitors were applied to the plants 24 hours after formation of the NR system, whereas NO<sub>3</sub><sup>-</sup> uptake was subject to a slight lowering. The above data suggest that WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> after a 24 hour application of these inhibitors to plants, primary inhibit biosynthesis and activity of NR and to a lesser extent effect NO<sub>3</sub><sup>-</sup> absorption. On the basis of results reached the Butz and Jackson (1977) hypothesis concerning the model of NO<sub>3</sub><sup>-</sup> uptake and reduction by plant tissues is discussed.


Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1145-1152 ◽  
Author(s):  
Shulin Liu ◽  
Yanxia Shi ◽  
Han Miao ◽  
Min Wang ◽  
Baoju Li ◽  
...  

Gummy stem blight (GSB), caused by Didymella bryoniae (syn. Stagonosporopsis cucurbitacearum), is an important disease of cucumber (Cucumis sativus L.) worldwide. To better understand the resistance to GSB in cucumber seedlings, a set of 160 F9 recombinant inbred lines (RILs) and a total of 405 pairs of SSR primers were employed to detect quantitative trait loci (QTLs) conferring the resistance. Genetic analysis indicated that the resistance to GSB in PI 183967 seedlings was quantitative and mainly governed by two pairs of major QTLs and multiple minor QTLs. Six QTLs, gsb3.1, gsb3.2, gsb3.3, gsb4.1, gsb5.1, and gsb6.1, for resistance to GSB in cucumber seedlings were detected. The stable locus gsb5.1 on Chr.5 was repeatedly detected in three seasons. Locus gsb5.1 accounted for the highest phenotypic variation, 17.9%, and was flanked by SSR15321 and SSR07711 within the genetic distance of 0.5 cM. There were 102 candidate genes predicted in the region harboring the stable QTL gsb5.1, of which seven genes were related to disease resistance. These results can provide a good base for further study and molecular markers for fine-mapping the major QTL conferring GSB resistance in cucumber.


2009 ◽  
Vol 21 (3) ◽  
pp. 175-186 ◽  
Author(s):  
Jamile F. Gonçalves ◽  
Alexssandro G. Becker ◽  
Luciane B. Pereira ◽  
João B. T. da Rocha ◽  
Denise Cargnelutti ◽  
...  

In this study, the effects of lead (Pb) on growth, photosynthetic pigments concentration, lipid peroxidation, electrolyte leakage percentage (ELP), protein oxidation, aminolevulinate dehydratase (ALA-D; E.C. 4.2.1.24), ascorbate peroxidase (APX; E.C. 1.11.1.11), catalase (CAT; E.C. 1.11.1.6) and superoxide dismutase (SOD; E.C. 1.15.1.1) activities, and ascorbic acid (AsA), non-protein thiol groups (NPSH) and total soluble protein concentrations in cucumber seedlings (Cucumis sativus L.) were investigated. Seedlings were grown in vitro in an agar-solidified substrate containing three Pb levels as (C2H3O2)Pb.3H2O (0, 100, 400, and 1000 µmol L-1) for 10 d. Increasing Pb concentrations in substrate enhanced Pb concentration in both roots and shoot. Pb accumulated at a higher amount in roots. Root length and total fresh weight were decreased at the two highest Pb concentrations. Cucumber showed no reduction in shoot length and total dry weight at any Pb level. The highest Pb concentration decreased water content and ALA-D activity as well as increased malondialdehyde, carbonyls and total soluble protein concentrations. Carotenoids concentration enhanced at 100 and 400 µmol Pb L-1, while chlorophyll concentration and ELP were not affected by Pb stress. Activity of APX was inhibited while the activities of CAT and SOD were increased at all Pb concentrations. AsA was enhanced at 400 and 1000 µmol Pb L-1 whereas NPSH were increased only at the highest Pb concentration. Therefore, high Pb-exposure caused oxidative stress, and the antioxidant system of the cucumber seedlings was not sufficient to revert it, contributing for growth reduction.


2012 ◽  
Vol 32 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Edilson Costa ◽  
Laura C. R. Vieira ◽  
Paulo A. M. Leal ◽  
Murillo C. de S. Jara ◽  
Priscilla N. de L. Silva

Culture environments, trays and doses of organic compost were evaluated in the formation of cucumber seedlings (Cucumis sativus L.). Five environmental conditions were tested: (A1) a greenhouse with height of 2.5 m, covered with polyethylene film, (A2) nursery with height of 2.5 m, monofilament fabric, 50% shading, (A3) nursery with height of 2.5 m, heat-reflective screen, 50% shading, (A4) nursery with a height of 1.8 m, covered with coconut tree straw and (A5) greenhouse with height of 4.0 m, covered with polyethylene film, with zenith opening and thermo-reflective cloth under the plastic. Trays of 72 (R1) and 128 (R2) cells were filled with 93% soil and 7% organic compound (S1), 86% soil and 14% organic compound (S2) and 79% soil and 21% organic compound (S3). It was used a randomized design in split-split-plot scheme, with five replicates (environments x trays x substrates). The greenhouses provide the best environments for the formation of cucumber seedlings. A tray of 72 cells is the best container, promoting more vigorous seedlings in substrate with soil and 7 or 14% organic compound.


2014 ◽  
Vol 50 (3) ◽  
pp. 429-436
Author(s):  
Genowefa Kubiak-Dobosz

Changes in the activity of glutamate dehydrogenase (GDH), alanine aminotransferase (GPT) and aspartate aminotransferase (GOT) were studied in various organs of <em>Cucumis sativus</em> L. seedlings in relation to the uptake of mineral nitrogen (in form of N0<sub>3</sub><sup>-</sup> or NH<sub>4</sub><sup>+</sup> ) from the medium. Activity of GDH, GPT, and GOT was higher in young leaves and roots of cucumber seedlings if the plants developed- in an ammonium medium. No similar changes of aminotransferases activity were noted in the cotyledons. Factors affecting varying effect of ammonium ions upon GPT and GOT activity are discussed for particular organs of cucumber seedlings.


2021 ◽  
Vol 22 (17) ◽  
pp. 9365
Author(s):  
Zili Feng ◽  
Fenghua Zheng ◽  
Silin Wu ◽  
Rui Li ◽  
Yue Li ◽  
...  

Cucumber (Cucumis sativus L.), an important vegetable plant species, is susceptible to low temperature stress especially during the seedling stage. Vacuolar invertase (VI) plays important roles in plant responses to abiotic stress. However, the molecular and biochemical mechanisms of VI function in cucumber, have not yet been completely understood and VI responses to low temperature stress and it functions in cold tolerance in cucumber seedlings are also in need of exploration. The present study found that hexose accumulation in the roots of cucumber seedlings under low temperature stress is closely related to the observed enhancement of invertase activity. Our genome-wide search for the vacuolar invertase (VI) genes in cucumber identified the candidate VI-encoding gene CsVI1. Expression profiling of CsVI1 showed that it was mainly expressed in the young roots of cucumber seedlings. In addition, transcriptional analysis indicated that CsVI1 expression could respond to low temperature stress. Recombinant CsVI1 proteins purified from Pichia pastoris and Nicotiana benthamiana leaves could hydrolyze sucrose into hexoses. Further, overexpression of CsVI1 in cucumber plants could increase their hexose contents and improve their low temperature tolerance. Lastly, a putative cucumber invertase inhibitor was found could form a complex with CsVI1. In summary, these results confirmed that CsVI1 functions as an acid invertase involved in hexose accumulation and responds to low temperature stress in cucumber seedlings.


1982 ◽  
Vol 30 (2) ◽  
pp. 137-148
Author(s):  
G. Heij ◽  
P.J.A.L. de Lint

Cucumber seedlings, cv. Farbio, planted in the greenhouse on 13 or 27 December or 10 or 24 January, were grown at 21-27 deg C day temperature and 12, 16 or 20 deg night temperatures until 1 April. Later planting produced more fruit than early planting. Night temperature had only a slight effect on fruit numbers/stem, but there was an optimum near 16 deg . The rate of fruit production between 12 and 20 deg was similar, but increased slightly with later planting. Production started earlier with higher night temperature and later planting. Fruit growth was not affected markedly by night temperature and fruit weight at harvest increased with season but was not dependent on the treatments. Fruit length was also independent of night temperature or planting date. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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