This study aimed to determine the variables that influence the mortality rate of Oligonychus afra... more This study aimed to determine the variables that influence the mortality rate of Oligonychus afrasiaticus (McGregor) (Acari Tetranchidae) dust mites and to explore potential control options for this pest. The important variables that were examined at included plant species, extraction method, concentration, and time. The findings indicated noteworthy impacts of these variables on the mortality rates of dust mites. The mortality rates of dust mites were significantly affected by the type of plant species (p < 0.01). The highest mortality rates were observed with Cymbopogon citratus, whereas there was no significant variation between Vitexm agnus-castus and Melilotus officinalis. The extraction method was Influential (p < 0.01), with ethanol extract performing better than aqueous and hexane extracts in terms of efficacy. Aqueous extraction had a lower efficacy than hexane extraction. The concentration of plant extract considerably affected the mortality rates of dust mites (p &l...
Date palm is one of the most important trees for economic and social development in many countrie... more Date palm is one of the most important trees for economic and social development in many countries and its fruits with high nutritional value. This aimed to determine the role of salicylic (SA) and jasmonic acids (JA) as antioxidants against salt stress. Salt stress was applied with water irrigation to two-year-old date palm offshoots by using 200 mM NaCl alone or in combination with foliar sprays of JA and SA at 1, 2 and 3 mgL-1. Results indicate that salinity at 200 mM NaCl remarkably increased the content of osmolytes (e.g., proline, glycine betaine and soluble sugars) in date palm leaves. Moreover, with the combination of 2 and 3 mg.L-1 SA and 1 mg.L-1 JA with salinity, the osmolyte content was remarkably higher than in salinity treatment alone. When date palm was exposed to salinity alone, the levels of oxidative markers, Malondialdehyde as a lipid peroxidation marker and H2O2 as a ROS accumulation marker, substantially increased compared with the control. Importantly, the leve...
The current study used the Fourier Transform Infrared (FTIR) spectroscopy to determine the corres... more The current study used the Fourier Transform Infrared (FTIR) spectroscopy to determine the corresponding changes caused by salt-induced biochemical changes at different NaCl concentrations (2.5 as control level, 5, 10, and 20 ds.m− 1). FTIR also determines the potential role of selenium nanoparticles (Se NPs) at two concentrations (80 and 160 ppm) in alleviating salinity stress on date palm (Phoenix dactylifera L.) trees. Notably, the study found the appearance of a new peak at 2850 cm− 1 in the lipid region (2800–3000 cm− 1) when date palm trees were exposed to salinity and tested at all levels. This peak was not seen in the control treatment or when salinity was combined with foliar spraying of Se NPs at the two tested concentrations (80 and 160 ppm). Furthermore, a clear and distinct peak at 1735 cm− 1 was only seen in plants exposed to salinity at 10 or 20 ds.m− 1. This peak was attributed to membrane lipid compounds that contain carbonyl-ester groups. In addition, the findings ...
Investigations were conducted on young date palm (Phoenix dactylifera L.) plants derived from tis... more Investigations were conducted on young date palm (Phoenix dactylifera L.) plants derived from tissue culture to evaluate their biochemical responses to cadmium and lead treatments through irrigation water. Changes in date palm metabolisms were observed as a response to heavy metals accumulation, the reductions in photosynthetic pigments as chlorophyll and carotenoides were obvious after 180 days of treatments, compared with the increase in anthocyanin pigments which was twofold more than control plants. It is noteworthy, that Cd and Pb treatments induced a significant decrease in chlorophyll stability index (CSI) to 66.97 and 58.79%, in Cd (9 mg/kg) and P (276 mg/kg), respectively. Stressed P. dactylifera plants tend to accumulate more carbohydrates, free amino acid and proline in their leaves as consequences of heavy metal treatments. Interestingly, the level of total soluble proteins was found to be less, up to twofold, than those in non-stressed plants. An excessive production of...
The leaves and soil of date palm (Phoenix dactylifera L.) were assessed for their pollution by di... more The leaves and soil of date palm (Phoenix dactylifera L.) were assessed for their pollution by different heavy metals (HMs) including Cd, Co, Cr, Ni and Pb. Three different areas at Basra governorate have been selected to be as rural (Shaat Al-Arab area - SAR), industrial (Najibiy Power Station area - NPS) and Al-Zubair high way area - ZHW. The concentrations of HMs were analysed in both soil and leaves by using Atomic Absorption. Results showed that the highest levels of pollution were observed at ZHW, both in soil and leaves samples; which were 58.20 and 19.50 mg kg-1, respectively, followed by NPS and reported the means of 51.30 and 11.90 mg kg-1, respectively. The lowest averages of pollution by HMs were seen at SAR area. It was found that the Pb concentrations were the highest among examined HMs and recorded the values of 115.0 and 40.40 mg kg-1, in soil and leaves of date palm, respectively, followed by Cr, while the lowest averages of pollution were observed with Cd in both soil and date palm leaves samples. The dominant of HMs found in the order of Pb&gt; Cr&gt; Ni&gt; Co&gt; Cd, in soil and date palm leaves. The highest levels of Pb, Cd and Ni were found to be exceeded the permissible levels of EU standards in the soils of ZHW and NPS, thus, required an urgent interaction to reduce these risky levels by suitable soil remediation procedures.
This study was aimed to investigate the oxidative responses and genetic stability of date palm Ph... more This study was aimed to investigate the oxidative responses and genetic stability of date palm Phoenix dactylifera L. under different irrigation water salinity, date palm off shoots cv. Barhi subjected to different concentrations of NaCl (100, 200, 300 and 400 µM) for 180 days. The obtained results showed that, the date palm responses to salinity stress, this responses was increased of H 2 O 2 level, Peroxidase activity and Malondialdehyde MDA concentration with increase NaCl concentration, while opposite trend with membrane stability index, which H 2 O 2 was increased from(0.73 µM/g) in control to (2.20 µM/g) in 400 µM treatment, MDA was increased from (2.35 nmole/g) in control to (nmole/g) in 400 µM treatment, also peroxidase activity was reached to (39.59 U/min/g) in 400 µM treatment, while was (20.73 U/min/g) in control and Membrane stability index reduction significantly from (81.36%) in control to (64.13%) in 400 µM treatment. In terms of genetic stability of date palm under ...
Heavy metals pollution has become a worldwide problem, and its toxicity affects crop yield, envir... more Heavy metals pollution has become a worldwide problem, and its toxicity affects crop yield, environment, human and animal health, as well as, soil fertility. In this study, the quantities of different heavy metals including Pb, Cd, Cr and Co have been assessed in Basra governorate. Soil and date palm Phoenix dactylifera L. leaves have been collected from different sites (Zubair highway, Najibya electric power station, Faw, Qurna, Shat Al-Arab and Abo Al-Kaseeb districts) during the rainy and dry seasons. The analysis of heavy metals revealed that the total, available and leaf content of Pb was found to be high at all investigated sites during both season, followed by Cr, while the lowest averages of heavy metals were reported with Cd. Results indicate that the total level of heavy metals pollution during the dry season was higher than what was observed during rainy season in all analysed heavy metals. It is noteworthy, that the levels of Pb and Cd in Basra's soils have exceeded ...
Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of le... more Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when...
The study was conducted to evaluate the effect of lead (Pb) stress
alone or in combination with s... more The study was conducted to evaluate the effect of lead (Pb) stress alone or in combination with salinity on the anatomical structure of roots and leaves of Date palm seedlings. Pb was added to soil at 100, 300 and 600 mg/kg concentrations as a pure aqueous solution or mixed with saline solution at 200 mM. Compared with the control, the microscopic study of root tissues showed that all treatments caused a significant increase in the thickness of epidermis, endodermis and pericycle, whereas the cortex thickness and diameters of the vascular cylinder, protoxylem and metaxylem decreased significantly. However, only the phloem diameter was affected significantly by 600 mg/kg Pb with or without salinity. Compared with the control, results on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb alone or in combination with salinity led to a significant increase in the thickness of cuticle layer, upper epidermis and lower epidermis. Results also showed a significant increase in the diameter of tannin and palisade cells when treated with 100 mg/kg Pb with or without salinity. Small vascular bundle diameter decreased significantly in seedlings exposed to Pb at all examined concentrations with or without salinity.
Scientific Journal of King Faisal University (Basic and Applied Sciences), 2020
Microbial contaminants are the major challenges in plant's in vitro propagation during different ... more Microbial contaminants are the major challenges in plant's in vitro propagation during different stages of culture processes, ZnO-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. The aim of present study was to evaluate the effect of ZnO NPs on microbial contamination; vitrification and growth promoting of date palm cultured tissues. Several concentrations of ZnO NPs were selected to assess their activity. The percentage of shoot formation, the number of proliferated shoot and the percentage of contamination of cultures were investigated, as well as several biochemical characteristics. Twofold of increase multiplication rate of proliferated shoot was observed in ZnO NPs at 150 mg L −1 compared to control treatment. The multiplication rate was 46.6% at control and increased significantly to 86.67% and 93.34% in ZnO NPs before and after sterilisation, respectively. No microbial contamination and vitrification were observed at all ZnO NP treatments compared with control treatment. Biochemical analysis showed that ZnO NPs had no toxic effects at all examined concentrations on date palm cultured tissues. A positive effect was observed in carbohydrates, protein and amino acid accumulations at high ZnO concentration (150 mg l −1). The results provide basis for the application of ZnO NPs in media date palm tissue cultures at 150 mg l −1 .
Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of le... more Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when plantlets were exposed to Pb, these traits decreased when plantlets passed from low to high concentration of Pb. Mesophyll thickness was decreased from 218.90 µm in plantlets grown in medium without Pb to 162 µm in plantlets grown in medium supplemented with Pb at 2.5 mg.L-1 , the mesophyll thickness increased in the plantlets passed from 2.5 to 5 mg.L-1 and reached to 465.16 µm. The same pattern of results was observed in the blade thickness; as well as; the number of vascular bundles and the width and height of vascular bundles. Our results demonstrate the usefulness of in vitro technique in testing and generating a tolerant clone of date palm to lead stress.
Journal of Genetic Engineering and Biotechnology, 2019
Background: Al is a common metallic element found in earth's crust and is a toxic pollutant prese... more Background: Al is a common metallic element found in earth's crust and is a toxic pollutant present at high concentrations in acidic soil, thus affecting plant growth. Despite being well studied as a toxic element, the effects of Al on date palm have not been investigated. This study aimed to assess the toxic effects of different Al concentrations on the development and growth of date palm callus and evaluate the biochemical and molecular response of date palm cells under Al stress. Results: Our study revealed the phytotoxicity of Al concentrations (50, 100, 150 and 200 mg.l-1) on date palm callus. The fresh and dry weight and the number of produced embryos were significantly decreased in response to Al concentration. At 150 mg.l-1 , the embryo number decreased to 1.66 compared with the 19.33 in the control treatment. At high Al concentration (200 mg.l-1), the callus failed to produce any embryo. Biochemical analysis revealed that Al exposure had negative effect on callus. Total soluble carbohydrates, total soluble protein and free amino acids were decreased in plants receiving 200 mg.l-1 Al treatment compared with those in the untreated ones. A similar decline was observed in total soluble protein and free amino acid in response to Al treatment. Significant accumulations of malondialdehyde, H 2 O 2 and peroxidase activity accompanied the increase in Al concentration in cultured tissues, revealing the generation of toxic reactive oxygen species in affected cultures. The genotoxic effect of Al at high concentrations (150 and 200 mg.l-1) was revealed by protein patterns. Conclusion: Our findings revealed for the first time the phytotoxicity of Al to date palm callus. At 200 mg.l-1 , Al prevented the embryo production of date palm callus. At 50, 100, 150 and 200 mg.l-1 , Al negatively affected the biochemical characteristics of date palm callus. At 150 and 200 mg.l-1 , Al induced changes in protein expression. These data showed that the tissue culture technique can be used as a valuable approach in heavy metal toxicity studies.
This study aimed to determine the variables that influence the mortality rate of Oligonychus afra... more This study aimed to determine the variables that influence the mortality rate of Oligonychus afrasiaticus (McGregor) (Acari Tetranchidae) dust mites and to explore potential control options for this pest. The important variables that were examined at included plant species, extraction method, concentration, and time. The findings indicated noteworthy impacts of these variables on the mortality rates of dust mites. The mortality rates of dust mites were significantly affected by the type of plant species (p < 0.01). The highest mortality rates were observed with Cymbopogon citratus, whereas there was no significant variation between Vitexm agnus-castus and Melilotus officinalis. The extraction method was Influential (p < 0.01), with ethanol extract performing better than aqueous and hexane extracts in terms of efficacy. Aqueous extraction had a lower efficacy than hexane extraction. The concentration of plant extract considerably affected the mortality rates of dust mites (p &l...
Date palm is one of the most important trees for economic and social development in many countrie... more Date palm is one of the most important trees for economic and social development in many countries and its fruits with high nutritional value. This aimed to determine the role of salicylic (SA) and jasmonic acids (JA) as antioxidants against salt stress. Salt stress was applied with water irrigation to two-year-old date palm offshoots by using 200 mM NaCl alone or in combination with foliar sprays of JA and SA at 1, 2 and 3 mgL-1. Results indicate that salinity at 200 mM NaCl remarkably increased the content of osmolytes (e.g., proline, glycine betaine and soluble sugars) in date palm leaves. Moreover, with the combination of 2 and 3 mg.L-1 SA and 1 mg.L-1 JA with salinity, the osmolyte content was remarkably higher than in salinity treatment alone. When date palm was exposed to salinity alone, the levels of oxidative markers, Malondialdehyde as a lipid peroxidation marker and H2O2 as a ROS accumulation marker, substantially increased compared with the control. Importantly, the leve...
The current study used the Fourier Transform Infrared (FTIR) spectroscopy to determine the corres... more The current study used the Fourier Transform Infrared (FTIR) spectroscopy to determine the corresponding changes caused by salt-induced biochemical changes at different NaCl concentrations (2.5 as control level, 5, 10, and 20 ds.m− 1). FTIR also determines the potential role of selenium nanoparticles (Se NPs) at two concentrations (80 and 160 ppm) in alleviating salinity stress on date palm (Phoenix dactylifera L.) trees. Notably, the study found the appearance of a new peak at 2850 cm− 1 in the lipid region (2800–3000 cm− 1) when date palm trees were exposed to salinity and tested at all levels. This peak was not seen in the control treatment or when salinity was combined with foliar spraying of Se NPs at the two tested concentrations (80 and 160 ppm). Furthermore, a clear and distinct peak at 1735 cm− 1 was only seen in plants exposed to salinity at 10 or 20 ds.m− 1. This peak was attributed to membrane lipid compounds that contain carbonyl-ester groups. In addition, the findings ...
Investigations were conducted on young date palm (Phoenix dactylifera L.) plants derived from tis... more Investigations were conducted on young date palm (Phoenix dactylifera L.) plants derived from tissue culture to evaluate their biochemical responses to cadmium and lead treatments through irrigation water. Changes in date palm metabolisms were observed as a response to heavy metals accumulation, the reductions in photosynthetic pigments as chlorophyll and carotenoides were obvious after 180 days of treatments, compared with the increase in anthocyanin pigments which was twofold more than control plants. It is noteworthy, that Cd and Pb treatments induced a significant decrease in chlorophyll stability index (CSI) to 66.97 and 58.79%, in Cd (9 mg/kg) and P (276 mg/kg), respectively. Stressed P. dactylifera plants tend to accumulate more carbohydrates, free amino acid and proline in their leaves as consequences of heavy metal treatments. Interestingly, the level of total soluble proteins was found to be less, up to twofold, than those in non-stressed plants. An excessive production of...
The leaves and soil of date palm (Phoenix dactylifera L.) were assessed for their pollution by di... more The leaves and soil of date palm (Phoenix dactylifera L.) were assessed for their pollution by different heavy metals (HMs) including Cd, Co, Cr, Ni and Pb. Three different areas at Basra governorate have been selected to be as rural (Shaat Al-Arab area - SAR), industrial (Najibiy Power Station area - NPS) and Al-Zubair high way area - ZHW. The concentrations of HMs were analysed in both soil and leaves by using Atomic Absorption. Results showed that the highest levels of pollution were observed at ZHW, both in soil and leaves samples; which were 58.20 and 19.50 mg kg-1, respectively, followed by NPS and reported the means of 51.30 and 11.90 mg kg-1, respectively. The lowest averages of pollution by HMs were seen at SAR area. It was found that the Pb concentrations were the highest among examined HMs and recorded the values of 115.0 and 40.40 mg kg-1, in soil and leaves of date palm, respectively, followed by Cr, while the lowest averages of pollution were observed with Cd in both soil and date palm leaves samples. The dominant of HMs found in the order of Pb&gt; Cr&gt; Ni&gt; Co&gt; Cd, in soil and date palm leaves. The highest levels of Pb, Cd and Ni were found to be exceeded the permissible levels of EU standards in the soils of ZHW and NPS, thus, required an urgent interaction to reduce these risky levels by suitable soil remediation procedures.
This study was aimed to investigate the oxidative responses and genetic stability of date palm Ph... more This study was aimed to investigate the oxidative responses and genetic stability of date palm Phoenix dactylifera L. under different irrigation water salinity, date palm off shoots cv. Barhi subjected to different concentrations of NaCl (100, 200, 300 and 400 µM) for 180 days. The obtained results showed that, the date palm responses to salinity stress, this responses was increased of H 2 O 2 level, Peroxidase activity and Malondialdehyde MDA concentration with increase NaCl concentration, while opposite trend with membrane stability index, which H 2 O 2 was increased from(0.73 µM/g) in control to (2.20 µM/g) in 400 µM treatment, MDA was increased from (2.35 nmole/g) in control to (nmole/g) in 400 µM treatment, also peroxidase activity was reached to (39.59 U/min/g) in 400 µM treatment, while was (20.73 U/min/g) in control and Membrane stability index reduction significantly from (81.36%) in control to (64.13%) in 400 µM treatment. In terms of genetic stability of date palm under ...
Heavy metals pollution has become a worldwide problem, and its toxicity affects crop yield, envir... more Heavy metals pollution has become a worldwide problem, and its toxicity affects crop yield, environment, human and animal health, as well as, soil fertility. In this study, the quantities of different heavy metals including Pb, Cd, Cr and Co have been assessed in Basra governorate. Soil and date palm Phoenix dactylifera L. leaves have been collected from different sites (Zubair highway, Najibya electric power station, Faw, Qurna, Shat Al-Arab and Abo Al-Kaseeb districts) during the rainy and dry seasons. The analysis of heavy metals revealed that the total, available and leaf content of Pb was found to be high at all investigated sites during both season, followed by Cr, while the lowest averages of heavy metals were reported with Cd. Results indicate that the total level of heavy metals pollution during the dry season was higher than what was observed during rainy season in all analysed heavy metals. It is noteworthy, that the levels of Pb and Cd in Basra's soils have exceeded ...
Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of le... more Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when...
The study was conducted to evaluate the effect of lead (Pb) stress
alone or in combination with s... more The study was conducted to evaluate the effect of lead (Pb) stress alone or in combination with salinity on the anatomical structure of roots and leaves of Date palm seedlings. Pb was added to soil at 100, 300 and 600 mg/kg concentrations as a pure aqueous solution or mixed with saline solution at 200 mM. Compared with the control, the microscopic study of root tissues showed that all treatments caused a significant increase in the thickness of epidermis, endodermis and pericycle, whereas the cortex thickness and diameters of the vascular cylinder, protoxylem and metaxylem decreased significantly. However, only the phloem diameter was affected significantly by 600 mg/kg Pb with or without salinity. Compared with the control, results on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb alone or in combination with salinity led to a significant increase in the thickness of cuticle layer, upper epidermis and lower epidermis. Results also showed a significant increase in the diameter of tannin and palisade cells when treated with 100 mg/kg Pb with or without salinity. Small vascular bundle diameter decreased significantly in seedlings exposed to Pb at all examined concentrations with or without salinity.
Scientific Journal of King Faisal University (Basic and Applied Sciences), 2020
Microbial contaminants are the major challenges in plant's in vitro propagation during different ... more Microbial contaminants are the major challenges in plant's in vitro propagation during different stages of culture processes, ZnO-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. The aim of present study was to evaluate the effect of ZnO NPs on microbial contamination; vitrification and growth promoting of date palm cultured tissues. Several concentrations of ZnO NPs were selected to assess their activity. The percentage of shoot formation, the number of proliferated shoot and the percentage of contamination of cultures were investigated, as well as several biochemical characteristics. Twofold of increase multiplication rate of proliferated shoot was observed in ZnO NPs at 150 mg L −1 compared to control treatment. The multiplication rate was 46.6% at control and increased significantly to 86.67% and 93.34% in ZnO NPs before and after sterilisation, respectively. No microbial contamination and vitrification were observed at all ZnO NP treatments compared with control treatment. Biochemical analysis showed that ZnO NPs had no toxic effects at all examined concentrations on date palm cultured tissues. A positive effect was observed in carbohydrates, protein and amino acid accumulations at high ZnO concentration (150 mg l −1). The results provide basis for the application of ZnO NPs in media date palm tissue cultures at 150 mg l −1 .
Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of le... more Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when plantlets were exposed to Pb, these traits decreased when plantlets passed from low to high concentration of Pb. Mesophyll thickness was decreased from 218.90 µm in plantlets grown in medium without Pb to 162 µm in plantlets grown in medium supplemented with Pb at 2.5 mg.L-1 , the mesophyll thickness increased in the plantlets passed from 2.5 to 5 mg.L-1 and reached to 465.16 µm. The same pattern of results was observed in the blade thickness; as well as; the number of vascular bundles and the width and height of vascular bundles. Our results demonstrate the usefulness of in vitro technique in testing and generating a tolerant clone of date palm to lead stress.
Journal of Genetic Engineering and Biotechnology, 2019
Background: Al is a common metallic element found in earth's crust and is a toxic pollutant prese... more Background: Al is a common metallic element found in earth's crust and is a toxic pollutant present at high concentrations in acidic soil, thus affecting plant growth. Despite being well studied as a toxic element, the effects of Al on date palm have not been investigated. This study aimed to assess the toxic effects of different Al concentrations on the development and growth of date palm callus and evaluate the biochemical and molecular response of date palm cells under Al stress. Results: Our study revealed the phytotoxicity of Al concentrations (50, 100, 150 and 200 mg.l-1) on date palm callus. The fresh and dry weight and the number of produced embryos were significantly decreased in response to Al concentration. At 150 mg.l-1 , the embryo number decreased to 1.66 compared with the 19.33 in the control treatment. At high Al concentration (200 mg.l-1), the callus failed to produce any embryo. Biochemical analysis revealed that Al exposure had negative effect on callus. Total soluble carbohydrates, total soluble protein and free amino acids were decreased in plants receiving 200 mg.l-1 Al treatment compared with those in the untreated ones. A similar decline was observed in total soluble protein and free amino acid in response to Al treatment. Significant accumulations of malondialdehyde, H 2 O 2 and peroxidase activity accompanied the increase in Al concentration in cultured tissues, revealing the generation of toxic reactive oxygen species in affected cultures. The genotoxic effect of Al at high concentrations (150 and 200 mg.l-1) was revealed by protein patterns. Conclusion: Our findings revealed for the first time the phytotoxicity of Al to date palm callus. At 200 mg.l-1 , Al prevented the embryo production of date palm callus. At 50, 100, 150 and 200 mg.l-1 , Al negatively affected the biochemical characteristics of date palm callus. At 150 and 200 mg.l-1 , Al induced changes in protein expression. These data showed that the tissue culture technique can be used as a valuable approach in heavy metal toxicity studies.
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alone or in combination with salinity on the anatomical structure of
roots and leaves of Date palm seedlings. Pb was added to soil at 100,
300 and 600 mg/kg concentrations as a pure aqueous solution or
mixed with saline solution at 200 mM. Compared with the control, the
microscopic study of root tissues showed that all treatments caused
a significant increase in the thickness of epidermis, endodermis
and pericycle, whereas the cortex thickness and diameters of the
vascular cylinder, protoxylem and metaxylem decreased significantly.
However, only the phloem diameter was affected significantly by 600
mg/kg Pb with or without salinity. Compared with the control, results
on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb
alone or in combination with salinity led to a significant increase in
the thickness of cuticle layer, upper epidermis and lower epidermis.
Results also showed a significant increase in the diameter of tannin and
palisade cells when treated with 100 mg/kg Pb with or without salinity.
Small vascular bundle diameter decreased significantly in seedlings
exposed to Pb at all examined concentrations with or without salinity.
alone or in combination with salinity on the anatomical structure of
roots and leaves of Date palm seedlings. Pb was added to soil at 100,
300 and 600 mg/kg concentrations as a pure aqueous solution or
mixed with saline solution at 200 mM. Compared with the control, the
microscopic study of root tissues showed that all treatments caused
a significant increase in the thickness of epidermis, endodermis
and pericycle, whereas the cortex thickness and diameters of the
vascular cylinder, protoxylem and metaxylem decreased significantly.
However, only the phloem diameter was affected significantly by 600
mg/kg Pb with or without salinity. Compared with the control, results
on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb
alone or in combination with salinity led to a significant increase in
the thickness of cuticle layer, upper epidermis and lower epidermis.
Results also showed a significant increase in the diameter of tannin and
palisade cells when treated with 100 mg/kg Pb with or without salinity.
Small vascular bundle diameter decreased significantly in seedlings
exposed to Pb at all examined concentrations with or without salinity.