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Peanuts (Arachis hypogaea L.) are a rich source of herbal oil, proteins, minerals, vitamins, fibers, essential amino acids, as well as bioactive compounds, and are thus widely used for human nutrition and animal feed, and for prevention from certain diseases. However, the in vitro regeneration response of the species is generally low, and it also displays a significant variability among its varieties. Thus, the development of advanced protocols and approaches for the in vitro propagation of peanut is still of immense importance. A recently developed in vitro propagation technique, TIS; Temporary Immersion Bioreactor System, provides a new approach for the mass propagation of plants. Accordingly, the present study provides an efficient de novo regeneration protocol for Arachis hypogaea L. cv. Virginia by using a TIS. Different concentrations of cytokinins, i.e., benzyladenine (BA) or thidiazuron (TDZ), were tested with several combinations of dry and medium immersion periods of TIS, corresponding to a total of 8, 12, 16, 24, 32, 36, 48, 64, 72, and 96 min daily immersions for the induction of direct organogenesis. The study exhibited that an MS medium added to 110 µM BA or 10 µM TDZ are the most appropriate medium formulations in TIS, when applied for 16 min every 16 h. The application of optimized procedures to cv. NC7 and two valuable Turkish autochthonous varieties, 7 × 77 and Com74, is also reported. To the best of our knowledge, the present study draws attention also for being the first study in which a TIS was used for peanuts. [ABSTRACT FROM AUTHOR]

Peanuts (Arachis hypogaea L.) are a rich source of herbal oil, proteins, minerals, vitamins, fibers, essential amino acids, as well as bioactive compounds, and are thus widely used for human nutrition and animal feed, and for prevention from certain diseases. However, the in vitro regeneration response of the species is generally low, and it also displays a significant variability among its varieties. Thus, the development of advanced protocols and approaches for the in vitro propagation of peanut is still of immense importance. A recently developed in vitro propagation technique, TIS; Temporary Immersion Bioreactor System, provides a new approach for the mass propagation of plants. Accordingly, the present study provides an efficient de novo regeneration protocol for Arachis hypogaea L. cv. Virginia by using a TIS. Different concentrations of cytokinins, i.e., benzyladenine (BA) or thidiazuron (TDZ), were tested with several combinations of dry and medium immersion periods of TIS, corresponding to a total of 8, 12, 16, 24, 32, 36, 48, 64, 72, and 96 min daily immersions for the induction of direct organogenesis. The study exhibited that an MS medium added to 110 µM BA or 10 µM TDZ are the most appropriate medium formulations in TIS, when applied for 16 min every 16 h. The application of optimized procedures to cv. NC7 and two valuable Turkish autochthonous varieties, 7 × 77 and Com74, is also reported. To the best of our knowledge, the present study draws attention also for being the first study in which a TIS was used for peanuts.

Eukaryotic translational initiation factor 4A belong to family of helicases, involved in multifunctional activities during stress and non-stress conditions. The eIF4A gene was isolated and cloned from semi-arid cereal crop of Pennisetum glaucum. In present study, the PgeIF4A gene was expressed under the regulation of stress inducible Arabidopsis rd29A promoter in groundnut (cv JL-24) with bar as a selectable marker. The deembryonated cotyledons were infected with Agrobacterium tumefaciens (LBA4404) carrying rd29A:PgeIF4A construct and generated high frequency of multiple shoots in phosphinothricin medium. Twenty-four T0 plants showed integration of both nos-bar and rd29A-PgeIF4A gene cassettes in genome with expected amplification products of 429 and 654 bps, respectively. Transgene copy number integration was observed in five T0 transgenic plants through Southern blot analysis. Predicted Mendelian ratio of segregation (3:1) was noted in transgenic plants at T1 generation. The T2 homozygous lines (L1-5, L8-2, and L16-2) expressing PgeIF4A gene were exhibited superior growth performance with respect to phenotypic parameters like shoot length, tap root length, and lateral root formation under simulated drought and salinity stresses compared to the wild type. In addition, the chlorophyll retention was found to be higher in these plants compared to the control plants. The quantitative real time--PCR results confirmed higher expression of PgeIF4A gene in L1-5, L8-3, and L16-2 plants imposed with drought/salt stress. Further, the salt stress tolerance was associated with increase in oxidative stress markers, such as superoxide dismutase accumulation, reactive oxygen species scavenging, and membrane stability in transgenic plants. Taken together our results confirmed that the PgeIF4A gene expressing transgenic groundnut plants exhibited better adaptation to stress conditions. [ABSTRACT FROM AUTHOR]

Multiple shoots in Arachis hypogaea L. could be induced from the de-embryonated cotyledons (DC), embryo-axes (EA) and mature whole seeds (MWS) in MS medium supplemented with different levels of benzylaminopurine (BAP). DC was the most suitable explant with 57.9 % induction and more than 40 shoots per explant in 31.6 % of cases. Though EA and MWS had high percent induction at or above 30 mg dm−3 BAP, only 10 – 14 shoots per explant were observed. In DC, multiple shoots were confined to the proximal end and in EA they originated from the axillary bud region. Histological studies on DC confirmed the origin of shoots from the region of attachment with the embryo. Shoots could be rooted in MS medium containing 2 g dm−3 charcoal and 200 mg dm−3 casein hydrolysate. Sixty percent of the rooted plantlets could be established in the field. [ABSTRACT FROM AUTHOR]

Mature de-embryonated cotyledons with intact proximal end of Vigna unguiculata were cultured on B5 basal medium containing varying concentrations of BAP. Thirty-six percent of the explants produced shoots on B5 medium supplemented with 8× 10 M BAP. Cotyledon explants were pre-incubated for 24 h, inoculated with A. tumefaciens pUCD2614 carrying pUCD2340, co-cultivated for 48 h and transferred to hygromycin-B (25 mg/l) containing shoot induction medium. Approximately 15-19% of the explants produced shoots on the selection medium. The elongated shoots were subsequently rooted on B5 basal medium containing hygromycin. The transgenic plants were later established in pots. The presence of hpt gene in the transgenic plants was confirmed by Southern blot hybridization. [ABSTRACT FROM AUTHOR]

Eukaryotic translational initiation factor 4A belong to family of helicases, involved in multifunctional activities during stress and non-stress conditions. The eIF4A gene was isolated and cloned from semi-arid cereal crop of Pennisetum glaucum . In present study, the PgeIF4A gene was expressed under the regulation of stress inducible Arabidopsis rd29A promoter in groundnut ( cv JL-24) with bar as a selectable marker. The de-embryonated cotyledons were infected with Agrobacterium tumefaciens (LBA4404) carrying rd29A:PgeIF4A construct and generated high frequency of multiple shoots in phosphinothricin medium. Twenty- four T 0 plants showed integration of both nos-bar and rd29A-PgeIF4A gene cassettes in genome with expected amplification products of 429 and 654 bps, respectively. Transgene copy number integration was observed in five T 0 transgenic plants through Southern blot analysis. Predicted Mendelian ratio of segregation (3:1) was noted in transgenic plants at T 1 generation. The T 2 homozygous lines (L1-5, L8-2, and L16-2) expressing PgeIF4A gene were exhibited superior growth performance with respect to phenotypic parameters like shoot length, tap root length, and lateral root formation under simulated drought and salinity stresses compared to the wild type. In addition, the chlorophyll retention was found to be higher in these plants compared to the control plants. The quantitative real time-PCR results confirmed higher expression of PgeIF4A gene in L1-5, L8-3, and L16-2 plants imposed with drought/salt stress. Further, the salt stress tolerance was associated with increase in oxidative stress markers, such as superoxide dismutase accumulation, reactive oxygen species scavenging, and membrane stability in transgenic plants. Taken together our results confirmed that the PgeIF4A gene expressing transgenic groundnut plants exhibited better adaptation to stress conditions.