Effect of ambient gases and soil moisture regimes on carbohydrate translocation in kidneybean plants grown in pots in Riyadh, KSA

This study designated to examine the effect of elevated gases in four localities of Riyadh City on carbohydrate for parts of kidneybean plants (Phaseolous vulgaris L.) grown in pots under two soil moisture regimes (well-watered vs. restricted water). Carbohydrate analysis results showed increases in kidneybean samples under well-watered conditions compared to restricted soil moisture. Most kidneybean samples at Embasses site exhibited higher soluble, insoluble and total carbohydrateconcentrations while the Batha site samples have lower values of these fractions. Batha site reduced the flux of carbohydrates from source to the sinks of both soil moisture regimes. This study concluded that there was a good relation between the effect of highly polluted localities and kidneybean leaves carbohydrate content and its translocation

Application of inter simple sequence repeat (ISSR marker) to detect genotoxic effect of heavy metals on Eruca sativa (L.)

As an influence of the Mediterranean diet, Eruca sativa (rocket salad) is eaten all over the world in salads and soups. It belongs to plant order Capparales (glucosinolate-containing species) and it is from the family Brassicaceae. Predominantly, the leaves of this species is eaten raw or cooked, although flowers are also consumed. Assessment of environmental contamination on ecology (plant) at molecular and population levels is important in risk quantification and remediation study. Heavy metal toxicity in plants is to induce oxidative stress linked to oxidation of proteins and membrane lipids but also to alterations of DNA damage response. E. sativa has been investigated in our study which is ofagronomical importance and widely used in European countries. We studied three heavy metals Zn, Pb and Cd which showed a dose-dependent effect on radicle and coleoptile lengths of E. sativa. Theradicle length was more affected than the coleoptiles length under all concentration tested plant. The ranking of genotoxic potencies in all three heavy metals was in the descending order: Cd2+ > Pb2+ Zn2+.Among these heavy metals, high concentration of Cd (150 mg/l) and Pb (150 mg/l) generated mutations along with changed morphology of seedlings. The radicle and coleoptile lengths (cm) under high concentration of Cd were decreased as compared to low, medium and high  concentrations treated seedlings with Pb and Zn. 20 ISSR primers were used, of which four did not amplify, three gave single band and the rest of thirteen primers generated upto six bands (an average of 4 bands per primer). Sixteen primers exhibiting amplified products gave monomorphic; only two primers (OPC-5 and OPC-7) gave unique extra band in seedlings treated with medium and high concentrations of heavy metals Cdand Pb, respectively. The dendrogram was constructed to evaluate the genetic distance generated among the seedling treated with various heavy metals at various concentrations. The similarity matrix values were found from 42.8 to 100% and these values showed the genetic divergence among the seedlings treated with various concentrations of heavy metals

Molecular diagnostics and phylogenetic analysis of ‘Candidatus phytoplasma asteris’ (16SrI- Aster yellow group) infecting banana (Musa spp.)

The presence of phytoplasma in diseased banana plants exhibiting acute stunting symptoms was detected by the polymerase chain reaction using a primer set specific for the 16SrRNA gene of phytoplasma. The amplified DNA fragments of 1500 bp were cloned in pGEMT-Easy plasmid cloningvector and sequenced. The BLASTN and phylogenetic analyses revealed the infecting agents to be the closely related members of the ‘Candidatus phytoplasma asteris’ (16Sr I-Aster yellow) group

Regulation in some vital physiological attributes and antioxidative defense system in carrot (Daucus carota L.) under saline stress

Regulation of some key metabolic phenomena including antioxidative defense system involved in plant salt tolerance is of great concern. Changes in chlorophyll pigments, chlorophyll fl uorescence and leaf gas exchange characteristics, glycinebetaine and proline contents, and enzymatic and non-enzymatic antioxidants was assessed in two carrot (Daucus carota L.) cultivars, DC-4 and T-29 under saline stress in a greenhouse study. Application of different saline regimes (0, 50, 100 and 150 mM NaCl) to the growth medium considerably reduced the shoot and root fresh and dry weights, shoot and root lengths, chlorophyll b contents, leaf water potential (Ψw), leaf osmotic potential (Ψs), photosynthetic rate (A), water-use effi ciency, sub-stomatal CO2 concentration (Ci), stomatal conductance (gs), transpiration rate (E), Ci/Ca ratio, leaf and root K+ and Ca2+ contents, leaf MDA, total phenolics, total soluble proteins, and activities of CAT, SOD and POD enzymes, while a marked increase was observed in leaf turgor potential (Ψp), leaf and root Na+ and Cl- contents, leaf proline, glycinebetaine (GB), ascorbic acid (AsA) and H2O2 contents in both cultivars. Of both carrot cultivars, cultivar T-29 was relatively higher in shoot and root fresh weights, root Na+, leaf and root Ca2+, leaf proline, MDA, total phenolics, soluble proteins and activity of SOD enzyme. In contrast, cultivar DC-4 was relatively higher in leaf Ψw and Ψs, leaf K+, root Ca2+ and leaf GB as compared to those in the other cultivar. The relatively better growth of cultivar T-29 was found to be correlated with improved leaf water potential, leaf Ca2+, proline, phenolics, and activity of SOD enzyme under saline conditions

Effect of ambient gases and soil moisture regimes on carbohydrate translocation in kidneybean plants grown in pots in Riyadh, KSA

This study designated to examine the effect of elevated gases in four localities of Riyadh City on carbohydrate for parts of kidneybean plants (Phaseolous vulgaris L.) grown in pots under two soil moisture regimes (well-watered vs. restricted water). Carbohydrate analysis results showed increases in kidneybean samples under well-watered conditions compared to restricted soil moisture. Most kidneybean samples at Embasses site exhibited higher soluble, insoluble and total carbohydrateconcentrations while the Batha site samples have lower values of these fractions. Batha site reduced the flux of carbohydrates from source to the sinks of both soil moisture regimes. This study concluded that there was a good relation between the effect of highly polluted localities and kidneybean leaves carbohydrate content and its translocation

Modulation of growth parameters, proline content and mineral nutrients in maize (Zea mays L.) by exogenously applied glycinebetaine at different growth stages under salt stress

Effect of glycinebetaine (0, 50 and 100 mM) applied as a foliar spray at different growth stages i.e. vegetative, reproductive and both at the vegetative and reproductive stages on growth, proline accumulation and ion accumulation was investigated in plants of two maize cultivars under saline conditions. Salt stress caused a significant reduction in growth, leaves and roots K+ and Ca2+ while, Na+ and Cl- concentrations of both maize cultivars was significantly increased due to salt stress. Foliar applied glycinebetaine at the vegetative stage was more effective in ameliorating the adverse effects of salt stress than when applied at the reproductive or at both vegetative and reproductive stages. Foliar applied glycinebetaine did not change the leaf proline concentration in the salt stressed plants of both cultivars. However, exogenously applied glycinebetaine significantly reduced Na+ accumulation in the roots and leaves, while that of K+ increased, thereby resulting in higher K+/Na+ and Ca2+/Na+ ratios under saline conditions