The proportion of TnBP in cell walls of shoots increased dramatically from 19% at 24 h to 43% at 72 h,suggesting translocation from the roots to shoots. However, less than 10% of TPhP in shoots subcellular fractions were found during exposure,which proved that TPhP did not readily transfer to shoots. Subcellular distributions of organophosphate diesters in roots were as follows: cell walls > cell sap ≫ cell organelles. less than 6.8% of organophosphate diesters were found in cell organelles of roots. For BCEP, the percentages in cell walls of roots decreased from 25% to 4.2% over time, which may have been due to upward translocation of BCEP via apoplast. The DnBP in roots was mainly distributed in cell walls with the molar percentage of 70–84%,indicating that TnBP hydrolysis principally occurs in cell walls. Electrical repulsion between the plasma membrane and anionic DnBP leads to the ion trap of DnBP in plant cells. Therefore, it would be difficult for DnBP to be transmembrane transported to the cell walls if intracellular hydrolysis of TnBP occurred. Moreover, the electrical repulsion of the plasma membrane also resulted in DnBP in cell walls being resistant to transmembrane transfer to cell organelles.It is supposed that TPhP hydrolysis occurred both intracellularly and extracellularly. The reason for the extracellular hydrolysis was the same as that for TnBP. Intracellular OPEs were able to be selectively bound to cytochromes P450 via hydroponic interaction and van der Waals force to generate metabolite products in wheat. Although CYP 450 are mainly distributed in cell organelles, it is speculated that DPhP could be released to the cell sap after hydrolysis in cell organelles. The ion trap prevents DPhP from being transported across the plasma membrane and transferred to the shoots. Overall, hydrolysis of OPEs in cell walls could be an important reason for the relatively high percentages of diesters in cell walls. In shoots, the molar percentages of diesters in cell walls were comparable to those in the cell sap. For example, up to 39% and 41% of BCEP were found in cell walls and cell sap of shoot at 120 h, respectively.

This could be attributed to the TCEP hydrolysis in shoots and BCEP translocation from roots. In comparison,round plastic pots much lower proportions of DnBP and DPhP accumulated in cell walls and cell sap of shoots. The DnBP was more prone to further metabolization,resulting that it would not accumulate in shoots. Relatively low TFs of both TPhP and hydrolysis metabolite DPhP were found,which can explain the low percentages of DPhP in cell walls and cell sap of shoots.Plants can absorb organic pollutants by active and passive uptake processes, mainly depending on the physicochemical properties and concentrations of chemicals. As energy-consuming processes are mediated by carrier proteins, chemicals can be transported against their concentration gradient in active uptake. In comparison, passive uptake, including simple diffusion and facilitated diffusion via carriers and channels without energy consumption, is driven by the chemical potential gradient. By adding metabolic inhibitors, active and passive absorption processes can be distinguished. Na3VO4 was used as a metabolic inhibitor by inhibiting the plasma membrane H+-ATPase to restrain the energy production of root cells. In this study, there were no significant differences  in RCFs of OPEs between the roots exposed to Na3VO4 or those that were not. This demonstrates that OPE uptake is a process without energy consuming when the external concentration is set to 100 μg/L. For many nonionic organic pollutants, such as polycyclic aromatic hydrocarbons,root uptake is a non-energyconsuming process. Non-energy-consuming uptake includes simple diffusion and facilitated diffusion via carriers or channels such as water channels and anion channels, which are important processes for anthropogenic chemicals to enter plants. Glycerol and AgNO3 are efficient aquaporin inhibitors. Anion channel can be divided into rapid-type and slow-type anion channels based on their kinetics and gating properties,and DIDS and 9-AC can block rapid and slow anion channels, respectively. 

As observed in this study, root uptake of TCEP was inhibited by 67% by AgNO3, while no significant effects on TCEP uptake were found when the glycerol and anion channel inhibited by DIDS and 9-AC was applied. The RCFs of TnBP decreased by 37% when treated with anion channel inhibitor 9-AC, and there was no inhibition of other inhibitors on TnBP uptake. Root absorption of TPhP was inhibited by aquaporin and anion channel inhibitors, with the RCFs of TPhP reducing by 27%, 49%, 31%, and 65% by glycerol, AgNO3, DIDS, and 9-AC, respectively.The results suggested that TCEP uptake by wheat roots was partly mediated by aquaporins, while aquaporins were also involved in root uptake of TPhP with aromatic rings. The mechanisms of aquaporins on uptake of hydrophobic organic pollutants with aromatic rings remain unclear. Conversely, there were no significant effects of aquaporin inhibitors on TnBP uptake. Similar results were found for di-nbutyl phthalate uptake by pumpkin,which indicates that root uptake of alkyl-substituted organic chemicals may be independent of aquaporins. The anion channels were implicated in uptake of TnBP and TPhP rather than TCEP. Na3VO4 had no significant inhibition effects on BCEP, DnBP or DPhP uptake,indicating that absorption of these OPEs hydrolysis metabolites did not consume energy neither. Both AgNO3 and 9-AC significantly inhibited root uptake of DPhP, with RCFs decreasing by 39% and 55%, respectively. In comparison, aquaporins and anion channel inhibitors had no significant effects  on BCEP and DnBP uptake. This indicated that BCEP and DnBP transport in plants might follow simple diffusion, while DPhP transport is dependent on aquaporins and anion channels. As discussed in Section 3.3, the internal tonoplast membrane is positively charged due to the lower pH in vacuole than in cytoplasm. Thus DPhP could be released into the cytoplasm after hydrolysis on the cell organelles, such as vacuole. Water-conducting channel or anion channel is required for DPhP to transport across organelle membrane.

However, the mechanism of selectivity of anion channels to the anion organic pollutants remains unclear, which needs further studies.Tomato  is one of the most consumed vegetables, not only in Pakistan but also in the world, and having a unique aspect of diet. Its fruit is widely used in vegetable mixes, salads, processed goods and as an integrative part of cuisines. The processed tomatoes are available as tomato ketchup, pastes, sauces and purees. The popularity of the tomato is obvious from the fact that it is rich in phosphorus, calcium, carbohydrates, and vitamin A and C. The diversity and standardized classification evaluation system is based on several morphological attributes ,physico-chemical and sensory quality ,nutritional values,content of vitamin C, texture, hardness, pH and acidity. In tomato industry, the overall production has increased due to its high demand among the consumers. All over the world, the rise of the fast food industry is also having a significant impact on the demand for tomato products. It is expected, that this trend will continue in the near future and the consumption of tomato is expected to increase further. In the recent years, a significant increase in area and production of the tomato crop has been reported in Pakistan. In the year of 2010–11, the area was increased to 52,300 hectares and production was about 529.6 thousand tons. The production of horticultural crops is extremely difficult in summer season due to a higher rate of infestation by pathogenic organisms. The cultivated tomato varieties in Pakistan are highly susceptible to hot climatic conditions. Moreover, due to seasonal variations,their production and supply remains far less than demand. The high temperature  has adverse effects on flower formation, fruit setting, vegetative growth, development and subsequent yield. In Pakistan, the tomato is marketed mostly during the end of winter and fruit production gradually decreases with increasing temperature. Therefore, the shortfall in demand supply chain occurs during the summer season. Commercial scale production of tomato and other solanaceous vegetables is significantly hindered by attacks of soil-borne diseases and sudden temperature fluctuation under the open field conditions. To cope with these challenges, the hydroponic bucket technique is considered a promising tool for commercial vegetable productions. 

However, utilization capacity of the soilless system in Pakistan has not yet expanded on a commercial scale due to higher capital investment. The hydroponic culture of tomato and other susceptible vegetable crops can facilitate their successful and profitable production. Therefore, a precise detection and management of biotic and abiotic stresses should be taking into consideration for immense production. Hydroponics is the most intensive method for crop production in the agricultural industry. It is highly productive, as it conserves water and land, and protects the environment. Hydroponics provides optimal conditions for plant growth compared to open field production. Therefore, higher yields can be obtained through it. It also offers a means of controlling pest and soil-borne diseases, which are especially desirable in the tropics, where the life cycle and infestation of these organisms continues in un-interrupted ways. This enables the plants to achieve higher growth of the shoot system with more vegetation, larger fruits, flowers and other edible parts. Plants in hydroponics grow up to two times faster with higher yields than with conventional soil farming methods due to higher oxygen levels around the root system, optimum pH along with increased nutrient and water uptake. Keeping in view the importance of tomato, it was imperative to carry out an experiment on different varieties of tomatoes  under greenhouse conditions by using hydroponics in Pakistan. The research evaluation was based on morphological, qualitative and analytical parameters, which are imperative for the development of rapid screening techniques and proper selection method of different tomato varieties. Therefore, the objective of this study was to explore the best variety under a hydroponic system and to evaluate its performance in terms of growth/yield and fruit quality.The description of tomato fruits  and plant growth of the cultivars Beefsteak & Cherry is shown in Table 1. In general, all tomato cultivars are indeterminate in growth habit, they attain an optimum height and then terminal bud of the primary shoot is transformed into a cluster. These cultivars were specially grown in hydroponic systems without any physiological disorders. Data analysis regarding plant height of Beefsteak  and Cherry  tomatoes indicated a significant difference at P ≤ 0.05. Significantly higher plant height was recorded in Cherry cv. Claree  and Beefsteak cv. Naram  while Cherry cv. Cheramy  and Beefsteak cv. Dirk  were shorter. These results did not coincide with the findings of Kaushik et al.,who reported that the average plant height of indeterminate variety was 9–12 cm. Plant height varies with the genotype and also depends on the recipe that is given in hydroponic production. 

The plant height of cv. Vernal was significantly shorter as compared to other, but their yield was higher. Mehta and Asati  reported the plant height is an important factor and because they have the highest positive effect on fruit yield. Regarding fruit size and fruit weight, the data showed a statistically significant difference in both groups  of cultivars. The fruit size and fruit weight of the Beefsteak group were significantly greater to the Cherry group. Among the Beefsteak cv. Vernal had significantly more fruit size  and fruit weight  as compared to other cultivars. In the case of the Cherry cultivar, the fruit size and fruit weight remained non-significant. These findings were similar regarding the range of fruit size from 5 to 7 cm,and range of fruit weight from 91 to 200 g. We observed that the fruit size plays an important role to increase the yield. The fruit size and fruit weight of the Beefsteak cultivars were greater than the Cherry, which showed the direct relationship regarding the yield. ‘Vernal’ showed a significantly more yield among the Beefsteak and Cherry cultivars. The plant yield depends on the weight and number of fruit. Therefore, the fruit weight was directly proportional to the yield of a plant.The obtained results exhibited significant differences regarding firmness between cultivars and it ranged from 3.01 to 4.83 kgf. Beefsteak cv. Naram was significantly more firm as compared to other Beefsteak and Cherry cultivars, while more softness was observed in the Cherry cv. Arial,but it was not significantly softer than cv. Claree, Nactar and Sahel. However, these values were higher than the ones reported by Arias et al.  for fresh consumption tomatoes grown under the hydroponic system.