‘Superior Seedless’ grafted on three selected grapevine rootstocks grown on calcareous soil under diluted brackish water irrigation. I. Growth performances

Mixing brackish water with conventional quality water for irrigation in ratios to maintain satisfactory vigor of grapevines might be a feasible man- agement practice. The objective of this study was to evaluate the performance of three grape rootstocks that are used worldwide and locally; R110, 41B and P1103, irrigated with three salinity levels: 1.5, 3.0 and 5.0 dS m-1 in addition to the 0.8 dS m-1 control. A randomized complete block design was used with three blocks of 12 pots each. ‘Superior Seedless’ grafted on P1103 showed bet- ter performance regarding chlorophyll content, stem length and number of young leaves and even growth after bud break. It does seem that grapevine rootstocks that have either V. rupestris or V. berlandieri in their parentage are good candidates for salinity tolerance. It can be concluded that irrigation with diluted brackish water can be practiced for a certain period of time (two months from April to June); according to our findings under conditions of the experiment, to be followed by irrigation with good quality water in order to flush excessive salts out of the root zone.

‘Superior Seedless’ grapevine grafted on three rootstocks grown on calcare- ous soil under diluted brackish water irrigation. II. Expression of antioxidant genes

Grapevine rootstocks that can absorb brackish water and maintain satisfactory growth of the grapevine scion might be a feasible management practice in areas suffering scarce water resources. The objective of this study was to evaluate the expression of antioxidant genes in ‘Superior Seedless’ leaves grafted on R110 (Vitis berlandieri x V. rupestris), 41B (V. berlandieri x V. vinifera) and P1103 (V. berlandieri x V. rupestris) in response to diluted brack- ish water irrigation at three levels: 1.5, 3.0 and 5.0 dS m-1 in addition to the 0.8 dS m-1 control. Results revealed that after salinity exposure for two weeks, the transcript levels of APX, Mn-SOD and MDAR increased in ‘Superior Seedless’ leaves grafted on the different rootstocks. However, their expression levels in response to salinity were noticeably higher in plants grafted on P1103 and R110 compared to 41B. The expression of CAT gene showed obvious enhanced level in plants grafted on P1103 in response to salt exposure. Meanwhile, the expres- sion of CAT gene in ‘Superior Seedless’ scion grafted on 41B or R110 showed almost unchanged level in control and stressed conditions. Down-regulation of CuZn-SOD was recorded in leaves of ‘Superior Seedless’ grafted on P1103. Slight up-regulation of this gene in response to saline condition was recorded when scion was grafted on 41B or R110. The expression of GPX was enhanced in scion grafted on P1103 and 41B. On the other hand, scion grafted on R110 showed decreased expression of GPX in response to salt treatment. Grapevine root- stocks that have V. rupestris and V. berlandieri in their parentage are good can- didates for salinity tolerance.

Propagación clonal y almacenamiento criogénico de la planta medicinal Stevia rebaudiana

Successful clonal propagation of Stevia rebaudiana was achieved using microshoots as a primary step for in vitro conservation. Maximum proliferation was obtained on Murashige and Skoog (MS) medium supplemented with 1.5 mg L–1 benzyl amino purine and 0.2 mg L–1 indole-3-butyric-acid (IBA). Auxin increased rooting percentage of shoots at concentration of 0.4 mg L–1 IBA, indole-3-acetic-acid or naphthalene acetic acid and no rooting occurred without plant growth regulator. A survival of 90% was achieved when rooted explants were acclimatized in vivo in 1 soil: 1 perlite: 1 peat. In vitro S. rebaudiana shoots were successfully stored for up to 32 weeks on MS medium supplemented with an appropriate concentration of sucrose, sorbitol or mannitol, at 24 ± 2°C. After 32 weeks, 93.6% of the shoots were able to survive. Moreover, 89.3% of them were able to regrow when stored under light conditions. Cryopreservation by vitrification was successfully achieved (65.6% regrowth) when shoot tips were precultured on a medium supplemented with 0.4 M sorbitol for 2 d, followed by loading shoot tips with 80% concentrated plant vitrification solution 2 (PVS2) for 20 min; then dehydrated with 100% PVS2 for 60 min at 0°C prior to storage in liquid nitrogen. This procedure is easy to handle and produced a high levels of shoot formation. This protocol could be useful for longterm storage of S. rebaudiana germplasm.Se logró con éxito la propagación clonal de Stevia rebaudiana, utilizando microtallos como primer paso para su conservación in vitro. Se obtuvo la proliferación máxima en el medio Murashige y Skoog (MS) suplementado con 1,5 mg L–1 de bencil amino purina y 0,2 mg L–1 de ácido indol-3-butírico (IBA). Las auxinas aumentaron el porcentaje de enraizamiento de los brotes en la concentración de 0,4 mg L–1 de IBA, ácido indol-3-acético o el ácido naftalen acético, pero no se produjo enraizamiento sin regulador del crecimiento vegetal. Se logró una supervivencia del 90% cuando los explantes enraizados fueron aclimatizados in vivo en 1 suelo: 1 perlita: 1 turba. Se almacenaron con éxito brotes de S. rebaudiana in vitro hasta 32 semanas a 24 ± 2°C, en medio MS suplementado con una concentración apropiada de sacarosa, sorbitol o manitol. Después de 32 semanas, el 93,6% de los brotes fueron capaces de sobrevivir y el 89,3% fueron capaces de rebrotar cuando se almacenaron bajo condiciones de luz. Se logró con éxito (65,6% rebrotes) la criopreservación por vitrificación cuando los ápices se pre-cultivaron durante 2 días en un medio suplementado con sorbitol 0,4 M, y a continuación con una solución de vitrificación de la planta 2 (PVS2) al 80% durante 20 minutos, seguido de una deshidratación con PVS2 al 100% durante 60 min a 0°C antes de su almacenamiento en nitrógeno líquido. Este procedimiento es fácil de ejecutar y puede ser útil para el almacenamiento a largo plazo del germoplasma de S. rebaudiana

Bioremediation of cadmium-contaminated water systems using intact and alkaline-treated alga (<i>Hydrodictyon reticulatum</i>) naturally grown in an ecosystem

<p>Cadmium can enter water, soil, and food chain in amounts harmful to human health by industrial wastes. The use of intact and NaOH-treated dried algal tissues (<i>Hydrodictyon reticulatum</i>), a major ecosystem bio-component, for Cd removal from aqueous solutions was characterized. Cadmium biosorption was found to be dependent on solution pH, bioadsorbent dose, the interaction between pH and dose, contact time, and initial Cd concentration. The experimental results indicated that the biosorption performance of alkaline-treated algal tissues was better than that of intact tissues. The maximum biosorption capacities were 7.40 and 12.74 mg g⁻¹ for intact and alkaline-treated bioadsorbents, respectively, at optimum operating conditions. Biosorption reaches equilibrium after 24 and 240 minutes of contact, respectively, for alkaline-treated and intact bioadsorbents. Cadmium biosorption was best fitted to Langmuir isotherm model (<i>R²</i> ≈ 0.99) and the kinetic study obeyed the pseudo-second-order kinetic model, which suggests chemisorption as the rate-limiting step in the biosorption process. Alkaline-treated algal tissues can be used as a new material of low-cost bioadsorbent for continuous flow rate treatment systems.</p

Clonal propagation and cryogenic storage of the medicinal plant Stevia rebaudiana

Successful clonal propagation of Stevia rebaudiana was achieved using microshoots as a primary step for in vitro conservation. Maximum proliferation was obtained on Murashige and Skoog (MS) medium supplemented with 1.5 mg L�1 benzyl amino purine and 0.2 mg L�1 indole-3-butyric-acid (IBA). Auxin increased rooting percentage of shoots at concentration of 0.4 mg L�1 IBA, indole-3-acetic-acid or naphthalene acetic acid and no rooting occurred without plant growth regulator. A survival of 90% was achieved when rooted explants were acclimatized in vivo in 1 soil: 1 perlite: 1 peat. In vitro S. rebaudiana shoots were successfully stored for up to 32 weeks on MS medium supplemented with an appropriate concentration of sucrose, sorbitol or mannitol, at 24 ± 2°C. After 32 weeks, 93.6% of the shoots were able to survive. Moreover, 89.3% of them were able to regrow when stored under light conditions. Cryopreservation by vitrification was successfully achieved (65.6% regrowth) when shoot tips were precultured on a medium supplemented with 0.4 M sorbitol for 2 d, followed by loading shoot tips with 80% concentrated plant vitrification solution 2 (PVS2) for 20 min; then dehydrated with 100% PVS2 for 60 min at 0°C prior to storage in liquid nitrogen. This procedure is easy to handle and produced a high levels of shoot formation. This protocol could be useful for longterm storage of S. rebaudiana germplasm.Se logró con éxito la propagación clonal de Stevia rebaudiana, utilizando microtallos como primer paso para su conservación in vitro. Se obtuvo la proliferación máxima en el medio Murashige y Skoog (MS) suplementado con 1,5 mg L�1 de bencil amino purina y 0,2 mg L�1 de ácido indol-3-butírico (IBA). Las auxinas aumentaron el porcentaje de enraizamiento de los brotes en la concentración de 0,4 mg L�1 de IBA, ácido indol-3-acético o el ácido naftalen acético, pero no se produjo enraizamiento sin regulador del crecimiento vegetal. Se logró una supervivencia del 90% cuando los explantes enraizados fueron aclimatizados in vivo en 1 suelo: 1 perlita: 1 turba. Se almacenaron con éxito brotes de S. rebaudiana in vitro hasta 32 semanas a 24 ± 2°C, en medio MS suplementado con una concentración apropiada de sacarosa, sorbitol o manitol. Después de 32 semanas, el 93,6% de los brotes fueron capaces de sobrevivir y el 89,3% fueron capaces de rebrotar cuando se almacenaron bajo condiciones de luz. Se logró con éxito (65,6% rebrotes) la criopreservación por vitrificación cuando los ápices se pre-cultivaron durante 2 días en un medio suplementado con sorbitol 0,4 M, y a continuación con una solución de vitrificación de la planta 2 (PVS2) al 80% durante 20 minutos, seguido de una deshidratación con PVS2 al 100% durante 60 min a 0°C antes de su almacenamiento en nitrógeno líquido. Este procedimiento es fácil de ejecutar y puede ser útil para el almacenamiento a largo plazo del germoplasma de S. rebaudiana

Ectoine, from a Natural Bacteria Protectant to a New Treatment of Dry Eye Disease

Ectoine, a novel natural osmoprotectant, protects bacteria living in extreme environments. This study aimed to explore the therapeutic effect of ectoine for dry eye disease. An experimental dry eye model was created in C57BL/6 mice exposed to desiccating stress (DS) with untreated mice as controls (UT). DS mice were dosed topically with 0.5–2.0% of ectoine or a vehicle control. Corneal epithelial defects were detected via corneal smoothness and Oregon Green dextran (OGD) fluorescent staining. Pro-inflammatory cytokines and chemokines were evaluated using RT-qPCR and immunofluorescent staining. Compared with UT mice, corneal epithelial defects were observed as corneal smoothness irregularities and strong punctate OGD fluorescent staining in DS mice with vehicle. Ectoine treatment protected DS mice from corneal damage in a concentration-dependent manner, and ectoine at 1.0 and 2.0% significantly restored the corneal smoothness and reduced OGD staining to near normal levels. Expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokines CCL3 and CXCL11 was significantly elevated in the corneas and conjunctivas of DS mice, whereas 1.0 and 2.0% ectoine suppressed these inflammatory mediators to near normal levels. Our findings demonstrate that ectoine can significantly reduce the hallmark pathologies associated with dry eye and may be a promising candidate for treating human disease